Opisthobranchiate Mollusca Collected by The

SPL’ RI LL A BRAZI L IA N A MA C FAELA N D 93

ot Th i l Fo . e oo i s ath e na w t er ost r or int o f t r r rro , ap ing p e y

sh o t blu nt o te d ta Th e t r ma i s hi k en d a r ly p in il . an e ior rgin t c e , h i st ct edi oo it s out e n s ar s or and wit a d in , m an gr ve, r a gle e h t i Pl X VI h o t . ﬁ The t ota le t t e oot i s p n ed , g . l ng h of f

mm iam t of it s nt io ort ion n an a ow n , the d e er a er r p , n rr i g i t mm . w o abo r t m d ay of it s lengt h .

r n l Th h l u n ea r ! o in Pha y geal bu b. e p a ryngea b lb is y val

ou t l n b r oad st on it s u e ost e io bor de th e sid s slo i n i e, e pp r p r r r, e p g w ot her w I n ont th e da r k b w n r ion t o ard ea ch b elo . fr ro n hi ge p o t

m u nt len t r nzn b - 18 r nr n an d h ei 'f h ea s em s h a d1h . r e are, g . , r ,

~ r I .8 r rm bei n fn ll on th sm ller than th e har n ra l b i h , g y e ird a p y g i

/ m n , m d m en si s f th e of s im .. s of S M a a e d th e sa on o pec p. p of e ho l y.

‘ i - Pl g l Th n éi l ( XV ﬁ s . 2 Hend r k e e rn s es . a a II, 9 , are

mm in ll Th r l n ov in ontli n .0 eat st sm a e a e e o ate a e . r . ey g l , 3 gr e w d i le m d ler man in eat st idt h . Each man b is a u g t h by . gr e e p

c of h e at im s the h ea th e b od an d th e m st i f r oces s. t r e V , d , y a y p r Th h ea i s m ass v st on ! a h ed i n on an d below an d e d i e, r g y rc fr t ,

f lm r s e u l u m hin Pl X ﬁ s d . a th c or e . . f r , g ( VII , g ﬂ, , 93,

da k ellow u d e it con ca i y di ect ed d ow n w s on c e s . tr g r y rv d ri g , v t r ard h i I n th e lef man dible t e cr est of h s id e i s sin l Pl t t r g g e . XVIII , ﬁ g ﬁttir 'f nt o v be w een th e di v r in d ouble . c oo 95, . ) i a gr e t e g g

( PL I I I ﬁ . cf . XV , g 94 , )

d g les s so b eh in i ts wh ole xt ent s t r on ma k e t b y h e , e ly r

sir r V i n Pl Pl . X ﬁ m a s 2 Th en t a a . . c . e s II, g 9 , 93 , ) v r l rg XVII,

n g o w a d c a v u wa an d le ck war d t o th e ost e io eh r of f r r , r i p rd p r r l h t h e fn r m ( PL I ﬁ g s se v s e r i~ c n . es a t nast XVI I, 94 , 95, It r h cat or w r n of t e man dibl an d sh ow s n o a f y gi e, tr ce o th e d i d es ch aract er i st i c of th e wh er sp eci es of Spu n! ! 74 OPISTHOBRANCHIATA OF BRAZIL

of mantle edge . The edges the foot are thin and crenulate . Its color i s in general the same as that of the under surface of the mantle . H ad e . The head is inconspicuous , the mouth a vertical slit,

ﬁ n er - bearing upon either side long slender g like oral tentacles ,

mm . in length , their tips blunt and cu rving forward .

R hi n o h or es r h in O h or es p . The p are brownish black, deeply retractile within conspicuous sheaths , with high tuberculate of of margins , the tubercules being the same type as those the general dorsal area . The sheaths reach a height of mm . , the whole slightly retracted rhinophore has a height of mm . of 2 The clavus is the usual club shape , perfoliate , with ca . 5 leaves on each side . The dark pigment is especially concentrated on of it: the strong stalk the rhinophore , where forms a circular band , immediately below the clavus . B r an ch i ae . The branchiae are six in number, bipinnate , completely retractile into the branchial pocket , which bears a conspicuous lobulate margin , the low divisions of which carry tubercules similar to those of the dorsum . The anal and renal openings are situated as usual within the circle of the branchiae . The reproductive openings in the specimen were very small and inconspicuous . D im en s i ons t f . o . Total leng h the whole animal mm ,

. of its width mm , and maximum height mm . Length

. of the foot mm , its width mm . ; greatest width the mantle margin mm .

INTERNAL ANATOMY .

Blood lan ds G . The dorsal integument is rather soft and

- not thick . The pseudo peritoneum is colorless , save in the regi on of the central nervous system where it is thickly sprinkled with minute , dark brown spots . The phagocytic blood glands , two in number lie directly in contact with the central nervous system ;

n the anterior larger o e is elliptical in outline and rather thick, mm measuring mm . in length by . in width and mm . in

thickness , and is dark gray in color , being sprinkled with minute

black spots . Its dorsal surface is arched , the ventral concave ,

while the general contour is smooth throughout . It lies di rectly

in front of the cerebral ganglia upon the pharyngeal bulb . The DI SCODORI S BRA N N ERI MA C FA RLA N D 75

posterior lobe is very much smaller and thinner , and lies trans v er sel it s y, anterior border in contact with the central nervous system . It is somewhat reniform in shape , measuring mm . in transverse by mm . in longitudinal diameter

ALIMENTARY SYSTEM .

L abial ar m atu r e. The oral tube is short and conical , mm . in length , bearing a colorless cuticula . The labial armature

i s of . small , consisting a median plate , mm in length by of tw o mm . in greatest width , and triangular lateral plates ,

t . . mm . in greatest leng h by mm . in width ( Pl XIII , ﬁg

- The median plate is elongate , spear shaped , and is made up of closely s et granular thickenings of the cuticle of varying size . Its median portion is marked by a narrow line in which the thickenings are much less numerous and are smaller than on either side . In the densest regions these granulations may assume r l the aspect of very short blunt od et s measuring up to mm . in diameter , and approximately the same in height . The median plate i s s et off from the lateral ones by a narrow of strip of cuticle , nearly destitute such elevations . The lateral plates are approximately right angled triangles in general ou t

e lines , the apex being directed backward , the perpendicular sid parallel to the median plate . The granular thickenings forming these lateral plates are of the same general type as those of the m d on e e ian , are very dense in the central portions and merge off gradually toward the periphery into the thickened cuticula su r rounding them . l R ad n a. The pharyngeal bulb is large and strong, mm . in length by mm . in height , in form truncately conical , the radula sheath proj ecting very slightly behind and below . The radula is broad , short, and deeply grooved , colorless in front , but

w - s i x becoming stra colored posteriorly . The teeth are in twenty of rows , the rhachis the radula is naked , and the pleural teeth

- vary in number from forty six in the anterior half rows , to

ﬁfty in the posterior ones . The dental formula may be expressed

- 6 ox 26. 4 5 The teeth are all simple hooks in form , the a m j ority except the outermost and innermost in each row , being f 6 68 o . . fi the same size and shape ( Pl XII I , ﬁgs 7 , ; Pl . XV, g . of The base a typical average tooth measures mm . , the height

LELA ND STA NFORD JUNIOR UNIVERSITY PUBLICATIONS UNIVERSITY SERIES

No. 2

THE OPISTHOBRA NCHIA TE MOLLUSCA

OF THE

BRA NNER—A G A SSIZ EXPEDITION TO BRA ZIL

FRA NK MA CE MA CFA RLA ND

Professor of Histology

Leland Stanford Junior Univer sity

! ITH PLA TES l XIX

TA N FO RD N I VER S I TY A L I FO R N I A S U , C PUB L ISHE D B Y THE UN I VE RSITY

J u n e . 1909

C O N T E N T S

INTRODUCTI ON

LIST OF OPISTHOBRANCHIATE MOLLUSCA COLLECTED BY THE

BRANNER- AGASSIZ EXPEDITION

LIST OF OPISTHOBRANCHIATE MOLLUSCA THUS FA R RE CORDED FROM THE COAST OF BRAZ I L DETAILED DESCRIPTIONS OF THE SPECIES COLLECTED

1 T dact lom el . ethys y a ( Rang) 2 Tethys cervina Dall and Simpson

l r r h i P eu ob n ass z i n ov . 3 a c u s ag i sp .

Di scodor is b r an n er i s n ov 4 . p . .

Di scodor i s on ih er in i s n o . v . 5 v g p .

6 Pel od r i r el t o s e i s n ov . g ey p .

r ill n . u a s ov . 7 Sp braziliana p .

LITERATURE CITED

EXPLANATION OF PLA TEs

6 OPISTHOBRA NCHIATA OF BRAZIL

of locality and date were taken by the collector , so that nothing

as or . can be given to the color, form of body in the living animal In the study of the collection most of the specimens have been r or dissected , and many parts have been cut into se ial sections , otherwise prepared for microscopical study . All of these prepara of tions , as well as the animals themselves , or what remains them , are deposited in the Zoological Museum of the Leland Stanford junior University, and their serial numbers are given under each species in the present paper . The following is a conspectus of the seven forms discussed in the following pages .

H H Order OPIST OBRANC IATA .

Suborder TECTIBRANCH IATA .

A l oidea Tribe p ys .

Family Aplysiidae .

d ct lom el 1 . a a Tethys y ( Rang) . 2 r D . Tethys ce vina all and Simpson .

Pleu r ob r an ch oidea Tribe .

Pleu r ob r an ch idae Family .

Pleu r ob r n h i z a c u s a ass i i s n ov . g p . S uborder NUDIBRANCHIATA . r i i Tribe Do do dea. D Family orididae .

Discodor idin ae Subfamily .

Di s odor i r n r . c s b a n e i s n o 4 p . v .

Di s d or i ih r n . co s v on e i i s n ov 5 g p . .

Di au lu li n ae Subfamily .

6 Peltodor i r l . s ee e i s g y p . nov .

A eolid oid ea Tribe .

Family Aeolididae . r ill . S u a s 7 p braziliana p . nov .

The complete list of the Opisthobranchiate Mollusca of the

Brazilian coast thus far described , together with those above i s as listed follows . Those marked with an asterisk are deep

. 100 water forms , i . e fathoms and over, and are of wide dist r i b u tion throughout the Atlantic Ocean . INTRODUCTION 7

H R H Order OPIST OB ANC IATA .

Suborder TECTIBRANCHIATA .

B ll idea Tribe u o .

Family Actaeonidae .

m i n n 1 cu . . Actaeon g A . Adams 20 0 1 Rio Janeiro , A . Adams , Proc . . 8 S oc . 1 . . , London , 54 , p 59

i n i u lid ae Family R g c . * 2 R in icu la er acu ta . . g p Watson

O ff 0 . Pernambuco , 35 fathoms Wat

6 6. s on . , Challenger Gasteropoda , p 3 i e D Rin u la . g c nitida V rrill all , m Har Bulletin Museu Comp . Zool .

188 . . vard , XVIII , 9, p 43

Tor n tin i ae Family a d . Tor n tin a li r ati s i r a a . 3 . p Smith

Rio Janeiro , E . A . Smith . Annals H . t and Magazine Nat is , IX , P 354

Tor n ati n a can ali u lata . c 4 ( S ay) . O PE Anchorage Fernando Noronha ,

- 2 t er . . G as O 7 5 fath Watson , Chall . p , 3 6 1 - 55 . * f 5 . Retusa ovata ( Jef reys ) . 0 Off Pernambuco , 35 fath . Watson ,

as r o 66 . . G t e . . Chall p , p 4

Family S caphandridae . * 6 Di a h an a se u en z ae . p g ( Watson) . ff O 0 . Pernambuco , 35 fath Watson , t r 6 G as e o . . 6 . Chall . p , p 4

C lich n a n or on en si . s 7 y y Watson . off or on h a Anchorage Fernando de N ,

- 2 . . G aster o . 7 5 fath Watson , Chall p , 666 p . .

8 C li ch n a . y bidentata

San S I h er i n Canal de ebastiao, Von g . 18 Revista Museu Paulista, I I , 97,

16 . p . 9 8 OPISTHOBRANCHIATA OF BRAZIL

Family Bullidae .

9. Bulla rubiginosa Gould . of H Near mouth Rio janeiro arbor,

Couth . Gould , U . S . Exploring

Exp . , XII , Mollusca and Shells , 18 2 5 , p .

10 u . . Bulla striata Brug i ere San S I h er i n Canal de ebastiao , Von g, 18 Revista Museu Paulista , II , 97,

. 16 p 9.

Man osou les . g , Managuas , Maceio i D . c . . S all , Proc . Wash Acad , III ,

1 0 1 . 1 2 . 9 , p 4

A er atidae Family c .

m n 1 1 Ha i ea . . elegans ( Gray)

i h an a ou th ou Bulla d ap C y .

Rio Janeiro , Gould , Mollusca and

S S . . hells , U . Exploring Ex , XII , 18 2 5 , p . H dat in idae Family y . m l n 2 Micr o e o u data . 1 . ( Brugu i ere)

! . on . D . Goyana , the reef all , Proc ash 1 0 1 1 2 Acad . S ci . , III , 9 , p . 4 .

A l ide Tribe p yso a.

A l sn dae Family p y .

13 . Tethys livida ’ f Ri r i n o o . d O b . Bay Janeiro g y, Voy ’ A r i 18 l m é u e . dans q Merid , V, 3 , 35 18 2 o6 4 3, p . .

1 . 4 . Tethys braziliana ( Rang) f u o Bay o Rio Janeiro . Q y and Gai H mard . Rang, istoire Naturelle des

l i n 2 A e s 18 8 . s . p y , , p 55 da t lom l 1 c e a . 5 . Tethys y ( Rang)

Maceio, Alagoas . Pernambuco .

Th e l a e of th e or n al e cr on of B lla r bi i n os a ou l an d B ll a T c igi d s ipti s u u g G d , u d i a h an a ou t h ou v en b ou l i n r e or on t h e oll a of t h e U . . p y , is gi y G d his p t up M usc S

x lor n x e on as r o o on S oc . a r al or I I I 1 8 . 1 0 an d 1 E p i g E p diti P c . B st N tu Hist y, , 4 9, p 7 9 ’ r e e i v el . h as b een c e i n ev e r al r ec en w or k e . . b l r i n Tr on sp ct y This it d s t s , g y Pi s y y s on ol o XVI a n . 0 n d 6. I am u n ab le t o ﬁ n d n u e r on i n a C ch gy, , pp 33 3 5 a y s ch d sc ipti y of t h e e ar l i er v ol m e of th e r o ee n s n or an aav l er e r on an t h e on e u s P c di g , y c i d sc ip ti s th s i n a e a o dic t d b v e. INTRODUCTION 9

D 16 . . Tethys cervina all and Simpson

Maceio , Alagoas .

1 N ot ar ch u la in l u s th s c u at Cou ou . 7 . ( y) H U . . Rio Janeiro arbor . Gould, S l r Ex o . 22 p . Exp . Moll , p . 3 .

Pl r r an h oi Tribe eu ob c dea. Pleu r ob r an ch id e Family a .

1 Pleu r ob r n h s s iz ii M F r l n d 8. a c u a a s ac a a g ,

s . p . nov D Riacho oce, Alagoas . Pl r o r n h e 1 . eu b a c a a 9 inconspicua Bergh . of u Mouth Coting iba River . Bergh , ’ Sem er s p Reisen , Wissenschaftliche M l l : a aco . . Resultate , VII Unters , 1 1 18 IV, , , 97 , p . 49.

Suborder NUDIBRANCHIATA .

Tr iton oid ea Tribe . Tr iton iidae Family .

20 . Tritonia cucullata Gould .

of Ex l Coast Brazil . Gould , U . S . p . 18 2 0 . . 8 Exp Moll , 5 , p . 3 . =Mar i on ia occidentalis Bergh . Chal 188 lenger Exp . , X , 4 , p . 49, La Plata

and Buenos Aires .

r i id Tribe Do do ea. ' D Family orididae .

A r ch idor idin ae Subfamily . 2 1 St au r odor i s . verrucosa ( Cuvier) .

a . Armacao, Province Sant Catarina

I h r in ah r e b . Von g, J deutsch . Mala

k oz l 8 6 2 oo . G es . 1 8 . 0 . , XIII , 3 , , p 3 — Stau r odor is anu ar ii l Ma . j Bergh . 18 8 H . 8 Unters , XIII , 7 , p . 5 3 ; Sup . . 1880 2 . . 18 10 1 . I , , p 37 ; System 9 , p . Di scodor idin ae Subfamily .

2 2 Di s odor i s b r n n r Ma F r l n . c a e i a d s c a . p .

nov . D Riacho oce , Alagoas . I O OPISTHOBRA NCHIATA OF BRAZIL

2 Di scodor i s v on ih er i n i Ma Far lan d 3 . g c .

sp . nov . D Riacho oce , Alagoas .

i lu lin Subfamily D au ae.

h or i s l i sla n n I h r i n 2 . T d a ad v o e 4 ( V g) . Von Armacao, Prov . Santa Catarina . h I h er in a r b G es . g, J . d . Mal . , XIII ,

6 . 2 188 . 3 , , p 34 h r i T o d sa . 2 5 . dubia Bergh H Rio Janeiro arbor, Rat Island ,

Bergh , Bull . Mus . Comp .

H 18 1 8. arvard , XXV, 94 , p . 7

l o r i r le Ma Far lan d s 2 Pe t do s ee c . . 6 . g yi p

nov .

D . Riacho oce , Alagoas

r i idid e Family D o op s a .

i si 2 D or O s . 7 . p atropos Bergh h r D a b . . . Rio janeiro . Bergh , J . d Mal 18 Ges . , VI , 79, p . 49.

A eolidoidea Tribe .

A li i d a Family eo d a e. A eolidian ae Subfamily .

' r ill Ma Far lan d s 2 8. u a c . Sp braziliana , p

nov . D Riacho oce , Alagoas .

Fav or in in ae Subfamily .

h i n l n 2 P di a a se e cae . 9. Bergh Beit r ae e Rio Janeiro . Bergh , g zur

n n n A eol i den Ke t i ss der id a . VI .

- lls h b . . G ese c . Ver . d . k . k . zool bot

18 8 . 60 . in Wien , 7 , p 5

Pl r O h llidid ae Family eu p y .

h r n 0 Pleu r O h llidia I e i . 3 . p y muelleri Von g S Armacao , Prov . anta Catarina , Von

h r in ah r . . I e b . . g, J d Mal Ges , XIII ,

In the above list the gym n osom atou s and thecosomatous ou t Pteropods have been left of consideration . Of the thirty INTRODUCTION I I

Bu lloidea species enumerated , the are represented by twelve , the

A l soidea Pleu r ob r an ch oi dea p y by ﬁve, the by two , the Trito n oid ea D or id oidea A li i by one , the by seven and the eo do dea by or three , nineteen Tectibranchs and eleven Nudibranchs as the total Opisthobranch fauna of some four thousand miles of coast ° ° ’ line , extending from 4 N . Lat . to 33 44 S . Lat . Of Bu lloidea A l soi dea these all the and p y are of wide distribution , many of them occurring throughout the North Atlantic, and others in the Antilles . It is readily seen from this that ou r information about the group in general , and the Nudibranchs in particular makes any theorizing as to distribution for the present somewhat premature . of of The appearance this paper , much which has been in manuscript for several years , has been delayed by other duties . Si x months spent at the Zoological Station at Naples in 190 3 enabled me to compare and dissect the Mediterranean forms related to those discussed in this paper . I again take the pleas ant opportunity of expressing my most cordial appreciation of the many kindnesses shown me while there by Professor D ohrn and ff his sta , as well as to the Smithsonian Institution for the grant of S a table in the tation , which opened these privileges to me . In the systematic arrangement of the Opisthobranchiata adopted in the present paper the plan of Pelsen eer has been followed in the main . The characterizations of the different su b

or Pilsb r divisions have been more less modiﬁed from those of y, Pelsen eer a of and Bergh in the m j ority cases . D PI TH B N HI T OR ER O S O RA C A A .

Marine Euthyneura with aquatic respiration ; the ventricle of n the heart is generally anterior , and the pallial cavity, whe

. r e present, is widely open There is a marked tendency to a or duction of the shell , which may become internal disappear .

In the naked forms spicules are sometimes developed .

D H SUBOR ER TECTIBRANC IATA . Hermaphroditic Opisthobranchiate Mollusca provided in the adult state with a mantle and shell , with certain exceptions ; with

on e . branchial plume and osphradium , with certain exceptions

B LL I DEA U O . TRIBE I .

S or hell usually well developed , sometimes wanting, external internal . Operculum seldom present . Pallial cavity well devel H oped and containing the usually plicate ctenidium . ead usually without tentacles , and with dorsal surface forming a shield , or usually separate from the neck, and with more less scalloped f i . E o o margins dges fo t ! continuous w th its ventral face and or often modified into fins . Stomach usually with chitinous cal ifi ed m r c masticatory plates . Visceral co missure usually rathe

m on au lic long . The genital duct usually connected with the penis by a ciliated groove .

A PLY I DEA SO . TRIBE II .

Shell much reduced , more or less internal , or lost altogether

H of . in the adult state . ead with two pairs tentacles Margins of of the parapodia separate from the ventral surface the foot, and generally modiﬁed into natatory lobes . Visceral commissure

r . usually very much sho tened , except in Tethys Genital duct m on au lic b , the hermaphroditic duct connected with the penis y a ciliated groove .

I 4 OPISTHOBRANCHIATA OF BRAZIL

r . lobe o lobes , rolled to form an excurrent siphon Genital oriﬁce under front edge of mantle , in front of ctenidium ; hypobranchial gland present , a short distance behind genital opening . Foot well developed .

Shell very thin , membranaceous , with a thin , calcareous inner layer , nearly as large as mantle , concave , with pointed , small apex , bearing a recurved lamina , and having a concave, posterior sinus .

A l s ia l This genus is usually known as p y , an etymologica of L a l s ia correction by Gmelin the name p y , used by Linné in the 2 f ou t Pilsb r 1 th edition o the Systema Naturae . As pointed by y , the name Tethys is unmistakably applied to this genus by Linné 10 th 1 8 himself in the edition in 75 , and hence must stand , despite the common but er r on eu s usage . Two species of this genus and on e of N otar ch n s have already of been recorded from the coast Brazil , and to them are to be m added the following two , already known fro the Antilles .

Teth s d act l om el a Ran y y ( g ,

P - - 1 i 1 Pl i P 4 . F . 38. I . s I s I 7 . F . 8 l . 9 I , Fi g . ; I I , g ; . II , Fi g ; Pl X , g A l s i d act lom el n A l si en s a a . H p y y Ra g istoire Naturelle des p y ,

182 8 . 6 , p 5 , pl . IX . Teth s d act lom ela Pilsb r y y ( Rang) . y , in Tryon , Manual of

- - 18 6 6 . 2 16 1 . Conchology , XVI , 9 , p . 75 7 , pl 3 , ﬁgs , 9

1 Length about 7 cm . Always much swollen with elongated or head and tail ; rugose . Mantle gill cover with a minute, central tube and a well developed siphon behind . Swimming lobes not united as far forward as the siphon .

! or Color pale yellow of various shades , more less covered in ff di erent individuals , with black rings , irregular and of various sizes . Inner sides of lobes and the mantle with large black spots of f of di ferent forms . Borders the swimming lobes tinged with violet . S hell large, much dilated , a little diaphanous , amber colored outside with a visible enamel within ; posterior sinus deeply

u arcuate ; beak recurved triang lar, thick and calloused . Altitude ,

- t w o forty millimeters . TETHYS DA CTYLOMELA ( R A NG) 15

EXTERNAL CHARACTERS .

Six specimens of this widely distributed Antillean species of were found in the collection , ﬁve them taken from the same ! 0 18 locality, Coral reef, Maceio, Alagoas , July 3 , 99, and the ! 18 sixth from Pernambuco stone reef, july 7, 99, and collected in both cases by A . W . Greeley . No further notes accompanied the specimens , but , according to a verbal communication from

M r . Greeley, the preserved material was of nearly the same col oration as in life , the ground color being slightly deeper , a yel on lowish brown . The characteristic ink ej ected being disturbed f six on e w as o . a deep purple color Of the specimens taken , was quite large , being over twice the length of any of the others , f which were o nearly the same dimensions throughout . All were of or in a good state preservation , but all more less contracted , especially in the region of the mouth and head . The following table gives a comparison of the principal dimensions .

! i dth Heigh t

m m m m m . . m m m m m

In individual No . 3 the anterior end of the left parapodium f 1 o . N os was 0 mm . behind that the right Side In individuals . 4 and 6 the contraction of the head region was so great as t o invalidate the measurements omitted in the table for all purposes of comparison .

o of as Col r . The general plan coloration is the same that ’ given in the revised description of this species in Tryon s Manual

‘

l . . f Vo . o Conchology , XVI , p 75 , and quoted above The black rings form a very striking color characteristic, their centers being m h free from pi g ent . T ey reach a diameter in the largest speci 16 OPISTHOBRANCHIATA OF BRA ZIL

of men of mm . , the band pigment itself ranging up to of mm . in width . The inner surface the parapodial lobes bears of several branching bands black, running in a generally vertical

direction , near the thin margins , with occasional isolated blotches of pigment between them , and below merging into the black to greenish black area at the bases of the parapodia . Between the posterior ends of the parapodia is situated a median longitudinal

dark band , which dilates posteriorly into a broad crescentic spot , the points of which are prolonged upward for a short distance along the inner face of the margins of the parapodia . The dorsal

surface of the mantle is marked with irregular blotches of black, tending to form a series of incomplete rings . The under surface of the mantle is yellowish brown , the branchia brownish black, or nearly free from color .

P ar a odi a p . The parapodia are prominent and high , their margins thin . The posterior half of the mantle is rolled into an of erect tube , the siphon , the thin crenulate upper margin which , in its slightly contracted state reaches j ust below the margins of the parapodia .

h ell of S . About midway of the length the mantle in the median line is a single minute opening, borne upon a well marked ,

sac short cylindrical papilla, communicating with the shell , or of mantle cavity . The shell is good size , rather convex , very thin and translucent , but slightly calcareous , externally very pale yellow in color . In all the specimens unfortunately it was some what broken , the inner calcareous surface being reduced usually e to fragments . The thin m mbranaceous margin of the shell pro ect s i j beyond the calc ﬁed portion beneath , its anterior and right borders are rounded , the posterior border concave , the beak much thickened , triangular and recurved . In general it is similar to 2 16 the ﬁgures of Rang for the species . Length 3 mm . , width of 0 mm . , in an animal 7 mm . total body length .

Ten tacl s e . The tentacles and head region generally are or more less contracted in all the specimens . In the best preserved

or r h in o h or es ones the posterior tentacles , p are slender, auriform , the external slit being carried down posteriorly nearly to the base of the organ .

The anterior tentacles are much broader, stout, auri form ,

con triangular in general outline , their outer margins being TETHYS DA CTYLOM ELA ( RANG) 17

t in u ed t o downward the mouth , the tips auriculate , their posterior margins forming a prominent ﬂap closely applied to the anterior portion . Just below and in front of the bases of the r h in oph or es the minute black eyes shimmer through the integument .

e in R ep r od u ctiv e op n g . The male genital Opening lies j ust of below the base the right anterior tentacle , a strongly deﬁned groove extending backward from it and dorsally between the para podia to the hermaphroditic oriﬁce in front of the base of the on branchia . This groove is marked by a narrow black line its right margin throughout its whole length . Behind and below

i s the genital Opening a large conspicuous circular oriﬁce , the h h of or Bo ad sc . opening the hypobranchial gland , gland of The anal Opening is situated upon the base of the posterior — of . wall the siphon , presenting a pocket like appearance

i s . The renal opening small and slit like, mm in length , and lies deep in the mantle cavity above the posterior end of the f o . ctenidium , some distance in front the anus Foot i s . The foot broad and well developed , its anterior end

on e . rounded , the posterior more bluntly pointed Its margin is m u scu la clearly deﬁned in all the specimens , its well developed ture being contracted , giving it a ﬁrm rugose texture , in contrast to the smooth soft surface of the remainder of the body . In the literature scarcely anything is to be found upon the of internal anatomy this species , a fact too frequently true of the of of of maj ority the members this family , many them having as Pilsb r been described by the shell alone, which , y has pointed

of . out , is probably the least characteristic organ the animal The interrelations of this widely distributed group cannot at present of even be approximated on account this lack . With a view to aiding in ﬁlling up this gap in ou r knowledge I have made detailed dissections of the Aplysiidae found in this collection .

I NTERNAL ANATOMY .

of In the description the internal anatomy, unless otherwise of stated , all the measurements given are taken from an individ f t o 0 . ual 7 mm . total leng h in the well preserved alcoholic specimen The body wall is similar t o that of other members of the group , the external integument being reinforced by interlacing 18 OPISTHOBRAN CHIATA OF BRAZIL

i s bands of strong muscle ﬁbres . The body cavity roomy, and

- nearly ﬁlled by the viscera , its pseudo peritoneum being colorless

or slightly yellowish in hue .

A LIMENTARY SYSTEM .

P r n eal bu lb b ha y g . The mouth communicates y a very short of tube with the pharyngeal bulb , a strong, muscular organ conical f t . o form . Its leng h is mm with a maximum diameter

- mm . Opened from above the deep , rich amber colored radula of is exposed , and in front it , upon each side , the mandibular

plates of a similar color . The latter are situated at the anterior of end the pharyngeal bulb , almost completely encircling the open

ing and nearly touching each other above and below . The opales i s as cent lip disc elliptical in outline , the opening appearing a

vertical slit , mm . in length , while immediately within it the

margins of the mandibular plates are seen . These plates are t u . . roughly rectang lar in outline ( Pl I , ﬁg their leng h being

mm . and their breadth mm . The posterior margin i s of bounded by a sharp , regularly cu rved line opalescent hue , or while the anterior margin is irregular , and more less j agged i s of r odlet s and worn . Each plate made up densely packed , or of nearly straight , slightly bent , and approximately the same

. t diameter throughout their whole leng h . At the posterior mar gin of the plate the arrangement of these r odlet s may be easily

seen ( Pl . III , ﬁg . but in the anterior portion such an arrange of ment cannot be made out clearly , owing to the overlapping

r odlet s i n r odlet s the as they increase length . The shorter are

- t o ﬂattened antero posteriorly, with a strong tendency the forma of or tion a slight concavity, longitudinal groove upon the poste rior face , and a corresponding convexity in front . Their average , greatest width is mm . Toward the anterior border the r odlets increase in length , their basal diameter remaining nearly the same , while the length may reach mm . The outer

on e- extremity is bluntly rounded , the distal third being some

or - or times slightly enlarged , club shaped , , in other cases , entirely straight throughout ( Pl . III , ﬁg . The bending and dis t or ti on as , incident to microscopic preparation a ! hole mount, of indicate a considerable degree ﬂexibility .

R ad nla. Th e i s o e nd of radula broad, deeply gro v d behind, a TETHYS DA CTYLOMELA (RANG) 19

a dark amber color . As is usual the anterior rows of teeth are s o i s u n very much worn and broken , that even their number m a ou t certain . About eleven such imperfect rows y be made ,

- of which gradually pass over into forty seven complete rows ,

which the last twenty are still inclosed in the radula sheath . The

i s ﬁ ft - Th e t total number of rows thus about y eight . greates mm its length of the radula is . , and greatest ! idth mm .

of ff The number teeth varies in the di erent rows , being

quite small in the most anterior rows , and increasing regularly

t o : 2 6 - fi fth r ow in the succeeding ones in the twenty , and fi ft —fi fth on e t o 3 38 in the y . In the anterior twenty twenty fi v e rows the teeth are much worn , scarcely any being perfect , or T the cusps being usually blunted , broken entirely away . ypical

teeth , taken at intervals across the radula from neighboring rows , f PI 1 2 o . . 1 are shown in figs . , and 3 , I . Fig represents the f th oth 2 median and first lateral teeth o the 49 and s rows ; fig . 8th th 1oth of fi s shows the , 9 and teeth the same rows, while g . 3 and 4 give the 18th t o 2oth of the 5oth r ow and the 32 d to 37th teeth of the 54th r ow respectively all under the same m agn ifi

. r ow I t s cation The rhachis bears a single large tooth in each .

base is broad and trapezoidal in form , the broader end being

directed posteriorly . It varies but slightly in size throughout of mm the length the radula , averaging . in the diameter of of its broader posterior end and mm . in the diameter it s t of anterior end, with a leng h mm . In the anterior of i s or end the radula the base often divided longitudinally, a thinning away of the median line may indicate such a division as incomplete . The posterior margin is very Slightly concave , the

on e n anterior deeply emarginate , the notch being carried up o the of as back the hook a deep groove . The anterior end bears a i s as f strong hook, which broad as the full width o the base at it s of anterior end . The length this hook averages mm . ,

- of seven twelfths the length the base . It terminates in a large tw o h median blunt cusp, and much smaller lateral cusps . T e sides of the median cusp bear from four t o ten thin irregular

on o of denticles either side in the posterior porti n the radula . or These denticles are either separate , more usually, united at their bases . In the anterior portion these denticles are either r l Th l o o . e Pl ﬁ worn away undeve ped latera cusps ( . I, g. are 20 OPISTHOBRANCHIATA OF BRAZIL

— - on e th e one fourth to on e half the length of the median , and , in last few rows may bear very minute serrulations , chieﬂy upon their outer margins .

The pleural teeth are rather uniform in outline , the inner most and outermost being slightly smaller than the remaining m ones , into which they pass in a graded series . The general for PI 6 of the pleural teeth is shown in . I , ﬁgs . 5 and , in dorsal and lateral view . The base is broadest and thickest at its anterior on e i s d end , tapering to a rounded posterior which produce strongly toward the outer border of the radula . In the posterior portion of the radula the base is broader throughout than in the anterior region . The same lateral prolongation is shown through

u t o the whole length of each row , being most strongly marked of about the middle of each ( Pl . I , ﬁg . The anterior end the base is recurved dorsally in a strong, broad hook, proj ecting ° upward at an angle of about 4 5 and bearing two strong unequal cusps , which are about as broad as long near the innermost ends of the row, and increase in length progressively until they become

on e- about two and half times as long as broad , a proportion 1 reached by the tenth tooth ( Pl . I , ﬁgs . , The smaller external cusp measures on e- half to on e- third the length of the of larger , and is the same general form . Both cusps bear typically a varying number of well marked irregular denticles

or upon their margins , which may be entirely separate , , as is usually the case , are united at their bases into a thin marginal band . These denticles may be fairly uniform in size and shape 2 ( Pl . I , ﬁg . , or more often , very irregular ( Pl . I , ﬁgs . 2 , The small external cusp bears a lesser number of denticles , t which may be few and small , or large and irregular , often a taining such a size as to give the cusp the appearance of being

. . f divided ( Pl I , ﬁg The dimensions o a typical large : of f pleural tooth are length base , mm . , greatest width o

. of t of base , mm , length larger cusp , mm . , leng h smaller cusp mm . The external pleurae decrease p r o r essiv el g y in size outwards , the outermost two or three in many cases being reduced to the base alone, the recurved hooks being undeveloped ( Pl . I , ﬁg .

D of 1880 obson in the journal the Linnaean Society ( XV, , p . ﬁgures several teeth from Tethys d actylom ela which agree

22 OPISTHOBRANCHIATA OF BRAZIL

on e of from these elevations . The largest the basal impressions thus left measured mm . in length by mm . in width . The teeth are arranged in a sort of quincunx in about six transverse rows , the larger ones occupying the middle and posterior por of tion , and in front these the smaller ones are alternately ar

of . . ranged . The largest these teeth measured mm in height of In the contracted state of this portion the stomach , the apices of these teeth meet in the center of the lumen and fi t closely together, thus nearly closing the Opening . Succeeding this first triturating stomach is a somewhat wider and longer, much thinner walled division of the alimentary ! ” f M z z ar elli o a . canal , the second triturating stomach Its walls of of are much less muscular than those the first stomach , being practically the same thickness as those of the ingluvies . Instead of bearing numerous small teeth as in those Mediterranean species studied by Maz z ar elli the teeth are reduced to a r ow of single series arranged in a transverse , about midway the of length the organ . These teeth are very small and readily dehiscent ; thei r basal impressions are nearly round in outline, and about mm . in diameter . There are seven such impressions in the first specimen dissected , six and eight in others , arranged in

on e- of a transverse row , and occupying about half the total ci r u m f er en ce of of of c the whole organ . The remainder the lining the second stomach is enti rely smooth .

P os ter i or v is cer al com lex of p . The hinder portion the second stomach is situated between the two anterior lobes of the large liver, thence passing rather abruptly into the intestine . The poste of rior visceral mass is made up the liver, the intestine and the hermaphroditic gland , and is broadly conical in general form , the apex being directed posteriorly, and the elliptical base lying against the posterior part of the stomach and partially inclosing it . It is covered by a delicate membrane of connective tissue ,

of - the peritoneal lining the pseudo coelom . The intestine is very f thin walled , and is ﬁlled with ﬁnely divided detritus o algal

. o nature It describes a series of complicated l ops upon the liver, of in the surface which it is imbedded . The intestine enters the liver at its lower border , passes backward , thence upward and forward describing a long loop upon the upper surface of the its liver toward right side, to return again to the left, from which TETHYS DA CTYLOMELA ( RANG) 23

to s it passes in a sinuous course the anu , situated upon the poste of of rior wall the siphon . At the beginning the intestine its tw o dilated lumen receives large biliary ducts , which ramify of Tw o throughout the substance the liver . low ridges , bounding a shallow groove, lie along the intestinal wall in contact with the f o . liver , near the beginning the tube These may be followed of backward into a long curved blind tube, in the wall which they become overlapping elevations , dividing it into two longitudinal chambers which are in communication at the end of the tube . of This , the hepatic coecum , is imbedded in the substance the liver throughout nearly its whole length , but its blind termination reappears at the surface as a small rounded area , which might

f or r of readily be mistaken a po tion the wall of the intestine .

The coecum describes a C shaped loop of nearly mm . in 1 lengt h with a fairly constant diameter of . 5 mm .

R CENT AL NERVOUS SYSTEM .

T e an lia of Teth s d act h g g . The central nervous system y y lo e PI 8 of m la . ( II , ﬁg ) is made up eight paired ganglia grouped of i ts around the anterior end the esophagus , close to origin from the pharyngeal bulb . These are the cerebral , the pleural , the of pedal and the buccal ganglia , the right and left components each pair being united by commissures , while the ganglia of each

b - - side are united y the cerebro pedal , the cerebro pleural , the

- - cerebro buccal and the pleuro pedal connectives . In addition to or these centrally located ganglia , there are others , more less distant from the central system . Chief of these are the parieto of visceral , the genital , and the ganglia the anterior and the poste rior tentacles . The central nervous system is closely enveloped of by a capsule connective tissue in a firm sheath , which renders ffi the dissection of the nerves a matter of some di culty . The ganglia , their commissures , connectives and nerves will be taken up in order in the following description . The figures and de scr iption s given by Von I h er in g Maz zar elli and of Teth s Vayssiere based upon European species y , vary so much from the results which I have obtained in Tethys d acty

om la T cer v in a l e and in . that considerable detail seems to be j usti P1 ﬁ . of 8 . ed in the following account . In ﬁg II I have endeavored t o give an accurate representation of the central nervous system 24 OPISTHOBRANCHIATA OF BRAZIL

of this Species in dorsal view , the abbreviations in the following description all referring to this ﬁgure . The nerves are numbered f rather arbitrarily in the order o their origin from the ganglia , from above and in front, downward and backward , the relative peripheral distribution n ot being primarily considered in this arrangement .

er e l N er cer C br a v es . . . The cerebral ganglia ( g ) are situated of upon the dorsal side the esophagus at its anterior end , and are so closely applied to each other that the cerebral comm issures connecting them are very short , the two ganglia being practically

‘ fused together in the median line into a single mass . They are rounded , and flattened upon their dorsal surface, and fit closely down upon the underlying esophagus . From the sides of the ganglia , close up to the origin of the fifth nerves , arise the strong

- c b . cerebro buccal connectives , ( . which curve downward , around the esophagus , to the buccal ganglia . Below and behind

- c . . the origin of these arise the cerebro pedal connectives , ( p which pass downward and outward to the large pedal ganglia ,

ed of (p . beneath the esophagus , and , close to the origin the

- l c . latter pai r, the equally stout cerebro pleural connectives ( . p con off . ) are given . These pass downward , outward and back l ward , and terminate in the small pleural ganglia (p . resting upon the upper border of the pedal ganglia .

of From the cerebral ganglia arise six pairs nerves , the origin and distribution of which is the same for both sides , unless otherwise noted in the following description .

a t on e The ﬁrst nerve ( ) is a strong , arising from the anterior of v border the ganglion , passing forward o er the pharyngeal of bulb , and is distributed to the skin and muscles in the region the mouth .

c2 The second nerve ( ) , is broad and strong, arising imme di at e t s l . i y behind the ﬁrst After a short course it bifurcates , more slender external division passing to the anterior tentacle , and terminating in a small ganglion at its distal extremity . The of stout inner branch splits up into a number smaller branches , all terminating in the integument in the neighborhood of the mouth .

c m The third nerve ( 3 ) , arises im ediately behind the ﬁrst , but more dorsally . It is more slender, and passes to the rhino TETHYS DA CTYLOMELA ( RANG) 2 5

off u phore, giving a few delicate branches to the integ ment near its base, and terminating in a small ganglion at its distal extremity .

or c The fourth , optic nerve ( 4 ) , is very slender and quite long . It arises immediately behind and exterior to the thi rd , and is inclosed in a common sheath of connective tissue with it f or a very short distance , much less than that described by Maz

z ar elli . for the Mediterranean Species It is unbranched , and passes directly to the eye . No trace of an optic ganglion can be ou t made at its base with the dissecting microscope , though sec tions might show it s presence .

c The ﬁfth nerve ( 5 ) , arises from the lateral border , imme di ately in front of the cerebro - buccal connectives and is rather slender . On the left side it courses forward and is distributed of to the body wall in the region of the mouth . Its fellow the

on e of right side passes forward , and divides into two branches , of which is soon lost among the muscles the body wall , imme di at l of e . y below the anterior portion the penis The second , more slender branch courses forward , parallel to the penis , giving off th e three branches at intervals , which pass to the latter organ , main nerve being ﬁnally distributed to the muscles of the mouth region .

r The sixth pair fo m the acoustic nerves . They are included — on e- t in the cerebro pedal connectives for about half of their leng h , d and then become separate from them as very elicate nerves , passing directly to the otocysts , rounded capsules lying close to

- the bases of the cerebro pedal connectives upon each side . These

n n I nerves are ot shown o P . II .

Ped al an li a d g g . The pedal ganglia (pe . are the largest of the central nervous system , mm . in greatest diameter, approximately circular in general outline, flattened upon the antero - ventral surface and strongly arched upon the postero dorsal face, thus having a nearly hemispherical form . They are m united below the esophagus by a stout , transverse com issure , t ( p . mm . in leng h , and mm . in diameter . This is inclosed within a broad , flattened sheath of connective tissue , which also contains near its upper anterior margin a very delicate subcerebral commissure , connecting the cerebral ganglia together below the esophagus . This latter commissure is so fine that it

' ou t s er ial i n is made with certainty only in transverse , sect o s of 2 6 OPISTHOBRANCHIATA OF BRAZIL

- i the whole band . From the ventro posterior marg n of each pedal ar a edal m m co . ganglion a much more slender p p com issure ( p . p . )

. of arises . It is mm in length , being more than double that the

thicker pedal commissure, and describes a posteriorly directed of loop below the esophagus . Somewhat to the left its middle

a off point a long slender unpaired nerve ( ) is given , in one case being formed by a union of a short branch from each side of the

loop , in others coming from the left side alone . It passes back

ward and is distributed to the pedal artery and foot . of From the pedal ganglia arise ten pairs nerves , which show such di fferences in the two sides that they are here described

separately .

L e d v . ft p e al n er es . The ﬁrst nerve is quite Slender It arises from the upper outer border of the ganglion and passes backward and is distributed to the peritoneum and muscles of the

posterior dorsum . The second nerve arises close below the ﬁrst and is

. on e of of similar size It bifurcates close to the ganglion , the rami thus formed passing backward to a similar distribution as that of the ﬁrst nerve ; the other ramus divides into ( a ) a branch curving forward and formi ng an anastomosis with a branch of b the second pleural nerve, described below, and ( ) a second

branch which is distributed to the muscles of the dorso - lateral

region .

The third p . is a rather slender nerve arising j ust below of the ﬁrst and second , and more upon the anterior face the gan on e it glion . In instance appeared as two nerves very close of together . It branches to the integument and muscles the dorsal b on e wall above the pharyngeal bul , branch passing undivided to

the region of the eye . The fourth nerve arises from the lateral margin of

the ganglion , is rather long and strong, passing backward to its of distribution in the anterior portion the parapodium .

- The ﬁfth p . is a strong nerve from the mid lateral ma rgin

of . the ganglion It soon divides into three branches , the anterior on e of of which passes to the muscles the body wall, the other

two to the parapodium . of The sixth nerve is the largest the pedal group . It of i arises close to the root the ﬁfth , and from its distribution s TETHYS DA CTYLOMELA ( RANG) 2 7

m termed the posterior pedal nerve . It soon divides into two ain of branches unequal size , which pass backward and ramify to of off the posterior portion the foot , giving a few slender branches

- to the mid lateral region of the same . — of From the ventro anterior face the ganglion , near the entrance of the cerebro—pedal connectives arises a very slender m nerve , the seventh A short distance below it , and fro the off same face , the ninth nerve is also given . These two nerves are closely enmeshed in the capsule of connective tissue enveloping the posterior end of the pharyngeal bulb , and may be easily overlooked . A short distance from their origin they are connected by an anastomosis , and beyond this the two have a similar distribution , branching richly to the peritoneum , the aorta ,

f - and the muscles o the dorso lateral wall of the body .

The eighth , or median pedal nerve , arises at the outer of lower margin the ganglion , passes outward and backward , dividing into two nearly equal rami , which are distributed to the median region of the foot .

or r o The tenth , anterior pedal nerve (p ) , is the lowermost

on e . of of the series It is about equal caliber to the eighth , and divides into three main branches which curve forward to the anterior portion of the foot .

i h t edal n er v es as R g p . The ﬁrst pedal nerve arises of a slender process from the outer upper margin the ganglion , of and soon divides into two unequal branches . The larger these passes directly to the muscles of the lateral wall . The other — branch subdivides again , in a short distance , into an anterior and of a posterior branch . The posterior one these innervates the

on OPE penis , the anterior e runs parallel to the latter organ , gives or two more delicate twigs to it , which anastomose with the sub of divisions the posterior branch , the main trunk terminating in the muscles of the mouth region on the right side . The second and third nerves are closely associated at thei r origin , some individuals showing them as separate nerves , while others Show the two united as a single nerve f or a ve r y short P1 8 . distance . In ﬁg . of . II I have shown the separate condition

Teth s cer v i n a In y , as will be seen , the united condition was of found , and further comment will be made in the description of the central nervous system that form . 2 8 OPI STHOBM N CHI A TA OF BRAZIL

The second nerve arises slightly in front of and below

on the third , in the instance ﬁgured the plate , passes outward and gives off a branch which forms an anastomosis with the ne r ve from the right pleural ganglion described below . The main branch passes to the lateral retractor muscle of the head , a slender

- branch also being distributed to the dorso lateral wall .

The third nerve is usually stronger , and is much

on e longer , coursing backward . It sends branch to the muscles of r on the dorsum , another fa ther to the muscles and integument of of Boh ad sch or the side , a third to the Organ , hypobranchial off of gland , and , after giving one or two branches to the muscles the body wall , ﬁnally terminates in the right parietal ganglion , — off thus forming a pedo parietal connective . The branch given to the Organ of Boh adsch also forms an anastomosis with a r e current branch from the second nerve of the l eft visceral gan

on glion , to be described farther . The fourth is a moderate nerve in diameter but quite of long . It arises from the right margin the ganglion , courses backward , and is distributed to the right parapodium , like its fellow of the Opposite side . of The ﬁfth nerve p . arises close in front of the root the sixth from the median margin Of the ganglion . Its strong trunk soon splits into three nearly equal subdivisions , the most anterior on e of which is distributed to the body wall in front of the para podium, the remaining two ramifying in the parapodium itself .

or on The sixth , posterior pedal nerve , is , as the left n f o e o . side , the largest nerves from the ganglion Its origin and of of relations are similar to those its fellow , which is also true 8 m the eighth (p . ) and tenth (p ) , the median and anterior pedal nerves respectively . In the last named there is a slight tendency to variation in the number of the main branches close to the ff ganglion , but otherwise these nerves present no great di erences on ff the two sides , nor in di erent individuals . of Close to the root the eighth nerve and a little behind it, on of the outer , posterior face the ganglion is found the origin of ar a ed al m the p p co missure ( p . p . Upon the left side this commissure originates from the inner ventral margin of the ganglion .

The seventh and ninth nerves , like the cor

30 OPISTHOBRANCHIATA OF BM ZI L

pleural ganglia , and equally unmistakable anastomoses occur

with a pedal nerve in each case . These relations will be taken

up in their order .

eu r l n r v s L eft pl a e e . From the outer upper margin of the l I l 2 left pleural ganglion arise two nerves (p . , p . ) close together , and are closely enmeshed in the capsule of dense connective tissue

surrounding the central nervous system . They are both dis tributed to the muscles of the lateral and dorsal body wall in the f of immediate vicinity o the ganglion . The second these nerves is connected by an anastomosing branch with the second pedal

nerve of the same side as is seen in the ﬁgure .

R i h t leu r l n er es g p a v . From the right pleural ganglion a l I of single , fair sized nerve arises ( p . ) below and in front the

- origin of the pleuro parietal connective . It passes outward and forms an anastomosis with a branch of the second pedal nerve

2 of . (p . ) the right side The double trunk thus formed then breaks up into a number of branches in the peritoneal membranes

- of and in the dorso lateral wall the body .

B u cc l an lia u c b . a g g . The buccal ganglia ( g ) are nearly vertically placed upon the posterior face of the pharyngeal bulb h eSO a u s . . just below the beginning of the p g ( Pl III , ﬁg 9) and present an anterior slightly concave face in contact with the

h n e o . bulb , and a posterior arc ed , turned away from it These

ganglia are plump rounded bodies of an elliptical outline , slightly

ﬂattened , and closely united in the median line by a broad and r ve y short commissure . On Plate II the buccal ganglia are shown in their relations with the’ remainder of the central nervous system ; in ﬁgures 10 and 1 1 of Plate III they are shown isolated

- - in ventro posterior and dorso anterior views respectively . The — c b . con short strong cerebro buccal connectives ( . . ) unite them to the cerebral ganglia above , being inserted laterally upon the posterior surface , between the bases of the second and third ﬁ s 10 buccal nerves ( Pl . III , g . 9, and and curving laterally upward to the cerebral ganglia . All the nerves of the buccal ganglia bear small white pigment spots arranged in a single series at regular intervals along their proximal portions .

B u ccal n er v es . In the description following the numbering of the nerves follows their order of origin from the anterior end of li n Maz z ar el o . the ganglia backward , an order followed by p TETHYS DA CTYLOM ELA ( RANG) 3 1

h i r fi Mon o a a f . 10 s o . 7 of g , but the notation his fig 9, tav IV does not follow the same , nor is there any reference made to the figure in the description .

on e The ﬁrst nerve is a strong, unpaired , median arising of upon the dorsal , median region the group by the union of a

1 1 I . large bundle of ﬁbres from each ganglion ( Pl . III , ﬁg . , ) It almost immediately bi furcates into two equal subdivisions which pass directly into the pharyngeal bulb , and are distributed to the

of . muscles the rotella , bearing the radula 10 1 1 The second nerve ( Pl . III , ﬁgs . 9, , , arises antero laterally and courses around the external face of the pharyngeal H t o of . bulb the attachment the lateral M retractor bulbi . ere tw o it divides into branches , the posterior one passing directly

r am iﬁ es of inward , among the deep muscles the radula , while the anterior branch courses forward and is distributed to the M . ant . lateralis bulbi , and to the deeper muscles of the bulb . 10 1 1 The third nerve ( Pl . III , ﬁgs . 9, , , arises close above the base of the second nerve and passes around the side of the bulb above and diverging slightly from it . At the posterior

- border of the M . antero lateralis bulbi it forks and passes beneath

off as that muscle, giving branches to it it passes deeper into the of bulb . It may be traced forward to the anterior end the

bulb , where its delicate branches are ﬁnally lost among the deeper , circular muscle ﬁbres .

10 1 1 The fourth nerve ( Pl . III , ﬁgs . 9, , , 4 ) arises from the of of lateral margin the ganglion , behind and above the origin h — the third , and passes upward over the postero dorsal face of the r pha yngeal bulb , following closely the external border of the proximal portion of the salivary gland to the appearance of its of duct at the surface the bulb . Near this point it penetrates the outer layers of the muscular wall , and passes forward in it to off the anterior end of the bulb , giving numerous branches to of the muscles the dorsal portion .

10 1 1 The ﬁfth nerve ( Pl . III , ﬁgs . 9, , , 5 ) is quite small , and

as of may be readily overlooked , or considered a branch the sixth one . It arises close to the base of the latter, between it and

on t o the fourth , and , the left side , seems indeed be a basal

of . 10 branch the sixth in many cases ( Pl . III , ﬁg , On the i it . s right side , however, is distinct in origin It probably to be 32 OPISTHOBRANCHIATA OF BRAZIL

of regarded as a salivary branch the sixth , as it is distributed

to the salivary gland , and thus would correspond to the branch shown by Maz z ar elli in the Neapolitan forms as arising well up

from the base of that nerve .

The sixth nerve is a strong and important one . It cor ’ Maz z ar elli s of responds to No . III of text , and to No . 4 his fig . 9, 10 1 1 of PI tav . IV . It is shown in figs . 9, and , . III as arising of from the posterior margin the buccal ganglion , and bifurcating off after a Short course . Its anterior division soon gives a median of branch which breaks up in the wall the esophagus , while the remainder continues forward between that organ and the salivary off gland , giving slender branches to each , and is finally dis tributed to the roof of the pharyngeal cavity at the beginning of the esophagus . The posterior division of the sixth nerve forms

h a — of the eSOp geo gastric nerve each side . It courses backward off along the esophagus , over the ingluvies , giving ﬁne branches

at intervals to its walls . At the anterior boundary of the ﬁrst triturating stomach these two main lateral trunks , together with of of several their branches , unite in a circular plexus ﬁbres f around the anterior margin of this division o the stomach . From this plexus , in which no ganglionic enlargements were found , of nerves pass into the wall . the digestive tube , and several ( six or more ) branches course backward to the second triturating of stomach , in the wall which they branch and anastomose ir

regularly , and thence are continued further back along the intes t in l a tract in a similar manner .

P r i et - is ce l n lia - a o v r a ga g . The position of the parieto visceral ! - of Maz z ar elli ganglia , the deuto visceral ganglia has been mentioned above in connection with the pleural ganglia . The two ganglia ( Pl . III , ﬁg . are completely fused together,

of forming a pear shaped mass, and Show indications their double nature at their anterior end alone, at the entrance of the two connectives . The right , or pleural ganglion is uppermost , lying

or directly above the left , visceral ganglia . From them are given off the following important nerves .

Vis cer al n er es v . From the left visceral ganglion arise three

. I v I nerves The ﬁrst of these ( . . ) , is the smallest . It originates

- of from the postero dorsal side the ganglion, and , dividing into TETHYS DA CTYLOMELA ( RANG) 33

of three main branches , is distributed to the vesicle Swammerdam and its duct . I v . The second ( . is a strong, ﬂattened nerve from the posterior right side of the ganglion . It passes backward along Off the body wall , giving a branch to the liver , another to the large

on hermaphroditic duct , a third which soon bifurcates , e sub division being distributed to the dorsal peritoneum and muscles ,

Off the other , recurving forward , gives a number of delicate

an ast o branches to the dorsal peritoneum and muscles , and itself

of v moses with a branch the third right pedal ner e , the united nerves sending a branch to the posterior face of the Organ of

Boh adsch r . The main trunk of the ne ve continues backward , penetrates the dorsal body wall , and bifurcates to the anal por of of tion the alimentary canal and to the walls the siphon . Close to the left of the second nerve arises an equally strong nerve , very soon dividing into two main trunks , which pass backward , diverging from each other . In the largest specimen these two trunks arose as separate nerves from the ganglion . I v a The left one ( . . 3 ) , of these sends a branch to the liver , a of more slender one to the muscles the dorsal body wall , while the main trunk curves upward around the posterior wall of the pericardium , and thence forward in its dorsal wall , and is dis t o tributed the heart and the kidney . The right main branch l v . b of ( . 3 ) , the third nerve sends a branch to the liver , another of to the large hermaphroditic duct , and , crossing the base the off adnexed genital mass , gives a branch to the small genital ganglion lying upon it . Crossing the small hermaphroditic duct , off it gives two branches to it , and , continuing backward , ﬁnally terminates among the muscles in front of the posterior portion of the alimentary canal .

Par i etal n er v es . From the right , or parietal ganglion arise of two nerves . A short distance behind the j unction the pleuro parietal connective with the anterior end Of the parietal ganglion ff r r . . I o . the ﬁrst ne ve ( p ) , is given It is a small trunk, sending of a number branches to the region of the genital opening, while

I a another branch ( ) , courses forward and unites with a branch of

- the third pedal nerve , thus forming a parieto pedal connective . In one individual the branch of the third pedal nerve continued on to unite directly with the parietal ganglion , close to the entrance 34 OPISTHOBRANCHIATA OF BRAZIL

- an ast o of the pleuro parietal connective , simply receiving a small mosing branch of the ﬁrst parietal nerve . r i m The second ( . p . is a very large nerve orig nating fro of of the dorsal side the posterior end the parietal ganglion . It passes backward for a short distance , and terminates in a good of sized ganglion , lying below the integument in front the branchia . From this ganglion a nerve is sent to the ctenidium of and the wall the branchial chamber , another penetrates deeply of of among the muscles the body wall , in front the kidney and n ot is probably distributed to the mantle , though its course could be made out with certainty . The main portion of the ganglion or S en el supplies the osphradium , organ of p g , a conspicuous oval of elevation with a depressed center , situated j ust in front and slightly above the base of the ctenidium .

THE REPRODUCTIVE SYSTEM .

The excellent work of Maz z ar elli upon the reproductive apparatus of the Aplysiidae has cleared up many doubtful points of in the structure and functions this complicated system , though of much remains still to be done . In the following discussion this system in Tethys dactylom ela I u se the nomenclature adopted by him . The reproductive system of the A plysu dae 15 made up of the of following structures , given in their order occurrence from behind forward .

1 or . . The ovotestis , hermaphroditic gland 2 . The small hermaphroditic duct . t of 3 . The adnexed geni al mass , consisting the nidamental

and albumen glands , the fertilization chamber , and the con voluted and spiral portions of the genital duct .

I f o . 4 . The spermatocyst and duct Cuvier

5 . The large hermaphroditic duct . m m r m m 6 or of Sw a e da . . The spermatotheca , vesicle

7 . The external spermatic groove .

8. The penis and its sheath . f The ovotestis forms the posterior end o the visceral mass , being more or less extensive depending upon the degree of sexual maturity of the individual . In the largest specimen at hand

mm . in total length ) the ovotestis is large , ﬂattened TETHYS DA CTYLOMELA ( RANO) 35

ovoidal in shape , all its surface being convex , save the anterior on e , which is irregularly concave to correspond with the surface of the posterior end of the liver and intestine , with which it is in close contact . Its surface is ﬁnely lobulate , light brown in

- color . From the antero dorsal surface appears the light brown small hermaphroditic duct, very strongly convoluted in its course,

mm . in average diameter, its length being approximately

. i m mm , though this could be estimated only, as it was possible to straighten ou t its windings . Its distal end passes of obliquely across the ventral side the adnexed genital mass , ! thence recurving dorsally to enter the latter . The adnexed ” genital mass is a term applied by Robert to designate a complex made up principally of the nidamental and albumen f glands and certain modiﬁcations o the genital duct . It is in

- the form of a dorso ventrally ﬂattened cone , situated obliquely of to the longitudinal axis the body . In the smaller Specimens on e it was nearly ﬂat , in the largest quite large and more pris

- a matic in form , its ventro anterior surf ce ﬂattened , the dorso

on e . posterior strongly arched In length it varies from mm . to mm . , and in width from mm . to mm . The of on e texture the largest was very ﬁrm and somewhat brittle , the great increase in size being due to the activity of the nida mental and albumen glands . The small hermaphroditic duct , of entering the anterior side the basal portion of the mass , dilates into an i rregular cavity , the fertilization chamber, into which Open the duct of the albumen gland and the duct of Cuvier from

. this fertilization chamber the genital the spermatocyst ! Beyond f or duct becomes very much convoluted a short distance , passing thence over into the Spi ral portion , which largely constitutes by of its windings the free portion the mass , and incloses in its loops the greater portion of the albumen gland . Throughout the turns of this spiral on e side of the duct is modiﬁed into the nidamental

‘ of of gland by a series complicated foldings , the lumina which communicate freely with the duct proper . Returning upon itself of ou t from the apex the mass , the spiral portion widens into the large hermaphroditic duct proper . By two longitudinal folds from Opposite sides of this large hermaphroditic duct it is in completely divided into two conduits . Owing to secondary twist ing the relation at ﬁrst existing of a right and a left portion 36 OPISTHOBRANCHIATA OF BRAZIL

f becomes modiﬁed in the course o the duct . At the proximal end the spiral portion of the genital duct is continued into the

on right half, while that the left is prolonged into the duct of the of spermatocyst and the duct Cuvier , the latter communicating with the fertilization chamber . These relations may be more ou t readily made in an immature than in an adult specimen , and

best of all , in serial sections . The spermatocyst is a pear shaped of sack, doubled upon itself, situated at the anterior margin the base of the adnexed genital mass , from which it proj ects freely

of t . for the greater portion its leng h . It is ca . mm long and mm . in maximum diameter in the largest specimen examined , but much smaller in the others . The large hermaphroditic duct extends from the adnexed of genital mass to the vulvar Opening, with a length mm . and a diameter of mm . in the largest individual . It is externally marked to correspond to its internal differentiation into tw o

on e on ov o- ducts , the the right the spermatic , that on the left of the copulatory duct . The latter duct , beyond the entrance the duct of the spermatocyst , becomes the vagina . The outer surface of the right of these ducts is of a yellowish brown color and f transversely rugose . The surface o the left half is smooth and dark brown . At a distance from the vulvar opening of about

- ﬁ fth one the whole length of the large hermaphroditic duct , the or of S duct of the spermatotheca , vesicle wammerdam opens into

or . the left copulatory duct The vesicle itself is a large , spherical structure , mm . in maximum diameter, lying immediately to

of - the left the parieto visceral ganglion . By a slender duct ,

mm . in diameter and mm . in length , in the largest speci i t men, communicates with the copulatory duct .

of The right half the large hermaphroditic duct , which

ov o- functions alike as oviduct and vas deferens , the spermatic ” - of Maz z ar elli duct, the ovidutto deferente , is continued forward as a narrow external groove along the right side of the animal of from the genital opening to the right side the head , close below the right anterior tentacle . In the largest specimen the H external spermatic groove measured mm . in length . ere it is continued inward along the inner wall of the penis sheath to its base , whence it recurves along the side of the penis to its tip , thus forming a conduit for the spermatozoa in copulation .

e h e v a D a n d m s on T t ys c r in ll a Si p .

- 1 - - - 2 39 4 . I I s 35 a e I X s . a es . V . 5 s Pl t I III , Fi g ; Pl t X , Fi g

i n Teth s cer v a D S . y all and impson , The Mollusca of Porto Rico

. S . 1 0 0 . Bulletin U Fish Commission , XX , 9 , Part I P1 6 2 2 6 . . . ( Issued Nov . 9, p . 3 5 , 5 , ﬁg

of Teth s One specimen a y different from the foregoing, ! 8 S . 1 1 . . . labeled and Beach , Maceio , Alagoas July 3 , 99 A W ” ac Greeley col . was found in the collection , no other notes Teth s companying it . In my opinion it is identical with the y cer v i n a of D S all and impson taken at Mayaguez , Porto Rico , and of D described in the publication cited above . The description all and Simpson is as follows :

Body elongated , ﬂabby ; mouth encircled by thick lips ; ten of S taeles short ; eyes inserted in front the tentacles . wimming lobes thick, united behind at some distance in front of the hinder extremity ; mantle oriﬁce minute ; mantle ending behind in a small

: fold foot narrow , nearly smooth . : Colors The body is a lurid gray , overlaid with reticula tions and blotches of darker color . It also has scattered , small , nearly round , smoky brown spots throughout its surface . The foot is smoky brown , lighter color than the spots . The inner edges of the swimming lobes are beautifully and distinctly macu late , with alternating light and dark patches . The mantle is colored like the body , but the dark spots are wanting, and the dark reticulations are somewhat radiating . Length 7 cm . ! of ou t Shell with a rather strong layer lime , elliptical in line ; posterior sinus moderate . Length of shell 30 ; breadth 1 9 mm . ! Mayaguez , Porto Rico .

The following points are based upon the Brazil specimen , and will serve as supplementary to the description of the former authors in anatomical details .

EXTERNAL CHARACTERS .

B od or m y f . The body ( Pl . X , ﬁg . is soft , plump and smooth , the head and caudal regions being rather contracted , the of remainder of the body but little distorted . The total length

0 . 20 . the specimen is 4 mm , its width and height being mm TETHYS CERVINA DALL AND SI MPSON 39

Color . The general color is a pale yellowish gray, sprinkled above and on the sides with minute dark brown spots . The of dorsal surface the mantle , covering the shell , is pale grayish , with ﬁne slightly elongate markings of dark brown arranged in inconspicuous radiate lines around the minute opening into of the shell cavity . These radiate bands dark color branch ir regularly above the periphery of the shell and merge into the of of general mottling the body . The sides the body are marked with a few ( eight to ten ) , irregularly scattered , larger, dark of brown ﬂecks , the largest which is not over mm . in diam of eter . The inner surface the parapodial lobes is marked with irregular dark brown maculations , alternating with lighter areas .

The foot is light brown throughout . These notes were all made from the specimens while in formalin . On being transferred to alcohol , the darker colors gradually became much paler and dis or appeared more less completely throughout . Foot . The foot is very narrow , being strongly contracted , t t o . especially midway of its leng h , there being reduced mm in width , but broadening in front to mm . , and behind to mm . , terminating in a short , bluntly pointed tail . The anterior of end the foot is broad and blunt with rounded outer angles . Par odi a a. 2 . t p The parapodial lobes are 9 mm in leng h ,

- of t occupying nearly three fourths the entire leng h of the animal .

They are rather low and not at all prominent, being but mm . in extreme height . The lobes are ﬂeshy, thei r margins thin and slightly undulating, being slightly rugose locally, a condition f probably due to contraction . The anterior ends o the lobes are th e . widely separated , interval being mm , which is lessened mm 0 . at the posterior end to 5 . though the lobes are distinct and n ot completely j oined behind the siphon .

Man tle . The mantle area is distended and plump , the minute central Opening into the shell cavity is borne upon a low papilla , which is rendered more conspicuous by the radiate pig mentation above described . On the right side the mantle extends

- in a thin edged semitranslucent ﬂap over the gill cavity . Poste r i or l y its right margin is deeply notched , the edges being elevated and rolled together, forming the prominent excurrent siphon , which extends backward and upward between the edges of the parapodia to a height of mm . 40 OPISTHOBRANCH IATA OF BRA ZIL

S h ell . The shell ( Pl . X , ﬁg . i s very thin and mem

b r an aceou s , the calcareous portion , small in amount , having been w as broken and detached , nearly all in small fragments in the

shell cavity . The outline of the intact membranaceous portion

is elliptical , with a moderate posterior sinus , as described by

Dall and Simpson . In length it measures mm . and in maxi

mum width mm . , though the membranaceous condition renders

the actual curvature a matter of some doubt .

Palli al cav i ty . The pallial cavity is roomy, the branchial of Teth s plume , the usual y type , i s nearly semicircular in out

line , and extends transversely beneath the shell , its left margin

reaching well to the left side , the right tip proj ecting slightly

from beneath the mantle margin .

A n al an d r en al op en ing . The anal Opening is pocket like ,

and situated upon the rear wall of the siphon tube , near its base . In front of it lies the small inconspicuous renal opening near

the base of the branchia .

H o r an chial lan d yp b g . The external opening of the Organ Boh adsch or of of , hypobranchial gland , lies upon the summit a

low thickened elevation , j ust below the anterior end of the base

of . . the branchia , and mm distant from it Upon the ventral surface of the anterior end of the base of the branchia is situated h t e . the osphradium , in form of an oval yellowish depression Through the transparent body wall of this region many of the

nerves from the parieto - visceral ganglion complex may be traced

for varying distances .

R r o u t i ep d c i v e op en ngs . The genital opening lies j ust in of of front the anterior edge the mantle , and is marked by an increased pigmentation which is carried backward along the body of Boh ad h wall toward the opening of the Organ sc . The female

portion of the Opening is oblique and slitlike , the portion lying above it is prolonged forward as a deep conspicuous groove

along the side of the body and head to the opening of the penis ,

close to the right anterior tentacle , upon the side of the head .

Ten tacl es . The anterior tentacles are strongly contracted ,

broadly auriform , with a well developed external groove . Their contracted condition precluded any even approximate measure

. or r h in o h or es ments The posterior tentacles , p , are also strongly contracted , extending but mm . above the surrounding su r TETHYS CERVINA DALL A N D SIMPSON 4 I

face . They are composed of the usual rolled plate with an external , auriform slit . The bases are wide apart being separated b y mm . distance .

INTERNAL ANATOMY .

The animal was Opened along the median line of the foot by a longitudinal incision , in order to disturb the viscera as little as possible . The peritoneum is colorless , the liver light chocolate , the grey windings of the intestine inclosing it in spiral turns .

ALIMENTARY SYSTEM .

P r n l u lb h a y gea b . The pharyngeal bulb is nearly spherical m and slightly elongate, the radula sack proj ecting fro its ventral surface as a prominent , rounded eminence . The salivary glands are long, slender and strap shaped , their relations being similar to e a A siid of Tethys d actylom l and other ply ae. A pair oblong lateral laminae , placed obliquely, the mandibular plates , ( Pl . III ,

s e ﬁg . guard the entrance of the pharyngeal bulb , being p r a ated above and below by a narrow interval . The extreme width of - a mandible is approximately two thirds of its greatest length , the actual measurements in the individual at hand being mm . f t . o in leng h by mm in width . The borders the mandibles of are rounded . Each lamina is made up a countless number of r odlet s ﬂexible, nearly straight with slightly dilated blunt tips

of . ( Pl . I II , ﬁg . having a maximum length mm and of a diameter mm . , the length decreasing toward the poste of rior border the lamina , the diameter remaining the same, the

- rodlet being somewhat ﬂattened antero posteriorly . The bases of the r odlet s are support ed by a homogenous horny cuticula of considerable thickness . R ad u la it s . The radula i s of a deep amber color in anterior older portion , becoming much lighter posteriorly . It measures

mm . in greatest length by mm . in width at its posterior end , tapering, at ﬁrst gradually, then more rapidly for the last

- ﬁ fth s of two its length to a rounded anterior end . The anterior

of n rows teeth are incomplete , being wor away and broken by

. 8 1 of use The teeth are arranged in 3 rows , the last 5 which of are inclosed in the radula sheath . The number teeth in each 42 OPISTHOBRANCH IATA OF BRAZIL row increases from : 16 in the oldest complete row to :22 of m a b e in the thirtieth . The dental formula this individual y

s x 1 - 22 ex pressed then a 38 6 . The rhachis bears a single, 6 m 2 . . 2 massive tooth ( Pl . IV, ﬁg . 3 ; Pl V, ﬁg , ) , its base, trap

idal ez o . in form , measuring mm in width at its posterior end and mm . in length , varying but slightly from these dimensions throughout the length of the radula . The posterior on e s o margin is slightly emarginate, the anterior deeply , the curve being carried up on the anterior face of the hook as a broad , deep groove . The anterior end is prolonged upward and backward in a strong hook, terminating in a stout, triangular , o of median cusp , up n either side which are borne two smaller of on e cusps typically . The larger these , next to the median , is from on e- half to two - thirds the length of the latter ; the outer ones are very much smaller and are more variable in both form and size . of With the exception the outermost three to ﬁve teeth , the of lateral teeth are strongly hooked and Similar form , decreasing

of . gradually in Size toward the outer borders the radula ( Pl IV,

2 2 - 2 fi s figs . 3 Each lateral tooth ( Pl . IV, figs . 3 5 Pl . V, g . 26 of consists a stout oblong base obliquely placed , from the dilated anterior end of which arises a stout hook, terminating in a triangular cusp . The sides of this cusp bear four to ten denticles , quite small near the tip and , in general , increasing in

i n f r e size toward the base , though irregularities in this are not f . o of o quent Upon the inner side each tooth , at the base the ho k, the series of denticles is terminated usually by a very large and of broad denticle, while upon the outer ﬂank the main cusp a of or i s of series two three smaller cusps borne . In the radula

Teth s d act lom ela on e y y there is but external cusp in this position , T cer v ina which is usually itself denticulate, but in . the margins

- 1 P1 . are uniformly smooth ( cf . Pl . I , figs . 5 , and . IV and V, figs 2 3 Indications of a fourth lateral cusp at the extreme end of this series are frequently found . The first ten laterals are

2 - 2 I - I o r e approximately equal in size ( Pl . IV, ﬁgs . 3 4 , ) , the maining ones decrease toward the outer border of the radula ( Pl .

IV, fig . the hook finally becomes rudimentary and disappears altogether, the outermost three to five teeth being reduced to of oblong flattened plates ( Pl . V, fig . The teeth this species TETHYS CERVI NA DALL A N D S I MPSON 43

are in general about two - thirds the size of those of Tethys dac t lom ela y . of The visceral mass nearly ﬁlls the body cavity the animal . of u of It is made up the esophag s , the three divisions the stomach , w and the intestine , the latter inclosing in its indings the liver and the ovotestis . Es o h a u s an d s tomach i s . p g The esophagus , short and rather or i n thin walled , dilating into the very ample ﬁrst stomach ,

l i . 1 u v es . g ( Pl VI , ﬁg 3 , a thin walled sack, densely packed m with frag ents of algae . The whole alimentary canal is spirally twisted from left to right, clockwise . The ingluvies occupies

on e or about turn of this spiral , the second , grinding stomach 1 m ( Pl . VI , ﬁg . 3 , . together with the third gastric division

n e- f completing about o half o the second turn . The anterior end of the ingluvies dilates rather suddenly from the esophageal tube, the posterior end tapering more gently to the broad band like circular constriction in the canal , marking externally the limits

of or . the thick walled , muscular , second , grinding stomach Pl 1 m t VI , ﬁg . 3 , . This portion is about mm . in leng h by o mm . in diameter at its anterior end , tapering somewhat p ste r i or l of y . Its inner surface bears a number strong horny teeth , of arranged in ﬁve somewhat irregular rows , the anterior ones which contain the smaller teeth , the succeeding ones increasingly of larger , and the last two the largest . The tips this gastric arma of ture meet in the center the lumen in the contracted condition , ff m of thus making a most e ective gastric mill . In general the for

i s of these teeth the same throughout , being that a four sided

a on e pyramid , the base rhomb in outline with of the acute angles directed fo r ward . In the largest teeth of the posterior rows ( Pl . l III , ﬁg . the crest is either single , rounded and b untly pointed , or wedge shaped , being prolonged into a transverse ridge . In m most cases this ridge shows three distinct sum its , separated from each other by Shallow depressions , which are continued downward upon the anterior face i n two deep grooves , while the posterior face is more uniformly convex . The base frequently p resents

cor a transverse median depression upon its ventral surface, responding in position to the region of greatest elevation above

( Pl . III , ﬁg . The smaller teeth , found in the two anterior t o rows , have a single groove upon the anterior face, carried up 44 OPISTHOBRANCHIATA OF BRAZIL

of the cusp , which is single, and may present the form a point 18 or of ( Pl . III , ﬁgs . , a transverse wall with a concave front of of face ( Pl . III , ﬁg . At the anterior margin each these smaller teeth rises a lower median cusp , which is connected by

on e . a lower sloping ridge with the posterior higher main ( Pl III , 18 ﬁgs . , All these teeth are borne upon thickened disks of epithelium with elevated margins and concave central portions , corresponding to the convex bases of the teeth .

PI . 1 The third stomach ( . VI , ﬁg 3 , 3 is nearly as thin

on e on e- walled as the ﬁrst , and is about fourth as long, being

t . mm . in leng h upon its greater curvature It increases in diam eter from the posterior border of the second stomach f or a short distance , then tapers as it becomes imbedded in the posterior visceral mass . The inner wall of the third stomach bears a of m circular band s all ﬂattened horny teeth , approaching close to the anterior margin of the stomach on the side of the lesser curvature , and arching backward from this region around the of greater curvature, there reaching a distance mm . from the anterior margin . The tooth bearing zone is mm . in width throughout its whole extent . The teeth are much more highly Teth s dact lom ela developed than in y y , are curved and conical in PI shape ( . III , ﬁg . and are much more irregularly arranged

’ than in the second stomach , small and large teeth being inter mingled . Behind this tooth bearing zone a few small and slender of teeth similar shape are irregularly scattered . I n te tin e s . The intestine is twisted in a slightly more com plicated way than the gastric region j ust described , the greater part describing a wide loop upon the left side and upper surface , the terminal portion then returning to the simple spiral form 1 f . . o in ( Pl VI , ﬁg 3 , Within the coils the intestine are of closed the liver and the ovotestis , the outer surface the former so showing throughout its whole extent , though deeply imbedded in the liver as to everywhere present a smooth surface . It is a

- simple , thin walled tube save at the most anterior portion , where it is dilated somewhat , and receives a slender diverticulum , the ! ” ll Z r 1 of Maz zar e i u cca di . h . hepatic coecum and ( Pl . VI , ﬁg 3 Upon opening the intestine at its anterior end a large f I o P . cavity in the substance the liver is disclosed ( . VI , ﬁg into which Open three large principal ducts and several smaller

4 6 OPISTHOBRANCHIATA OF BRAZIL order of their appearance from in front and above downward and backward . All abbreviations in the following description refer to ﬁg . 34 , Plate VII , unless otherwise indicated .

er e r al an lia cer C b g g . The cerebral ( . g . ) ganglia are com

let el p y fused together into a large quadrilateral mass , all traces of thei r primitive separation into right and left moities having of disappeared . The nodulated dorsal surface the mass is highly arched , the ventral slightly concave . In width the complex

1 . . k measured 5 mm , in length mm . and in thic ness mm .

s u b - A slender, esophageal , cerebral commissure passes below the esophagus , connecting the halves Of the ganglionic mass together 6 m . . . s co . ventrally In ﬁg 34 , Pl VII , . . , it i s seen inclosed in the same sheath of connective tissue as the pedal commissure and it s lying at anterior margin .

r e r al n r v e i x Ce b e s . From the cerebral ganglia arise s pairs of of nerves and three connectives , the origins which are the same for each side .

c I The ﬁrst cerebral nerve ( . ) arises from the anterior outer of t o face the ganglion , and courses forward to its distribution the skin and the muscles of the mouth region . 2 The second cerebral nerve ( c . ) arises immediately behind

r the ﬁrst , and is much larger . It cu ves forward along the off pharyngeal bulb , giving , midway of its length , a strong outer branch to the anterior tentacle , in which it terminates in a small ganglion . The main trunk breaks up into a number of divisions , which are distributed to the muscles and integument of the mouth region . c The third cerebral nerve ( . 3 ) arises from the upper dorsal of border the ganglion , and is distributed mainly to the rhino phore , in which it terminates in a small ganglion . It also gives

r of off two o three slender branches , the ﬁrst and largest which forms , apparently, an anastomosis with the optic nerve . It is not a true fusion , however , the two nerves being merely united f or in a common , epineural sheath a short distance . The dis t r ib u tion of this and the other slender branches of the third nerve i s to the integu ment in the neighborhood of the eye and c rhinophore . Upon the right side a true anastomosis o curs with

r x a branch of the second pedal ne ve , as shown at . in the ﬁgure

n and to be described further o . TETHYS CERVINA DALL A N D SI MPSON 4 7

c u n The fourth , or Optic nerve ( . 4 ) is slender , long and branched . It arises from the dorsal margin of the ganglion and passes outward and upward to the eye . No special optic gan glion can be made out at its base without serial sections .

r c - The ﬁfth cerebral ne ve ( . 5 ) arises from the postero lateral of of o face the ganglion , immediately above the origin the cerebr buccal connectives . It is a rather slender nerve , passing forward of of and ramifying to the muscles the mouth region . That the right side sends , in addition , a branch to the penis .

or The sixth cerebral , auditory nerve , is closely associated with the cerebro - pedal connectives and is not Visible in d orsal of view . It arises close to the base the connective , and follows it to the upper face of the pedal ganglion where it terminates in the otocyst , being throughout its course inclosed in the connective

f - c tissue sheath o the cerebro pedal connective ( . p .

of Three sets connectives arise from the cerebral ganglia ,

- - - the cerebro buccal , the cerebro pleural and the cerebro pedal .

The ﬁrst named pair is the longest , arising from the outer ventral of of margins the ganglia , and encircling the anterior end the esophagus to unite with the buccal ganglia beneath . They are

- n ot . c visible in ﬁg 34 . The cerebro pedal connectives ( . p . pass obliquely outward and backward from their origins upon — the postero ventral margin Of the cerebral ganglia to the pedal

a ed gangli (p . They are short and thick, and are inclosed in a strong connective tissue sheath with the cerebro- pleural con n ti e c l ec v s . . of ( p which are nearly equal diameter, but less long .

P d al an li ed . e g g a. The pedal ganglia ( p are rounded m m ﬂattened structures , measuring . in diameter and mm . in maximum thickness . They are connected below the esophagus by a strong commissure (p . mm . long and mm .

ar a edal wide . A much longer and quite slender p p commissure

( p . p . arising from the lower posterior margin of each ganglion also unites the two . Upon the upper margin of the pedal ganglia are received the cerebro—pedal connectives and j ust

- behind them the very short pleuro pedal ones . From each gan

O ff glion ten nerves are given . These will be described f or the right side, any difference which may exist upon the opposite one being noted . The nerves are taken in order and numbered in the 48 OPISTHOBRANCH IATA OF BRAZIL

of series from the upper anterior margin the ganglion , downward

For r and backward . the ne ves originating along the outer margin f of the ganglion this presents no di ﬁculties , but those nerves w hich arise from the median portion of the ventro - anterior face are of necessity more arbitrarily assigned their position in the series as indicated .

P e l n e I i s r on e d a r v es . The ﬁrst nerve ( ) , a ve y slender , — arising from the upper ventro anterior face of the pedal ganglion , j ust below and external to the entrance of the cerebro - pedal con

n ectiv e . , and very close to the origin of the second nerve It passes outward and forward to the integument in the eye region .

The second nerve i s similar in size to the ﬁrst nerve , arises quite close to it , and in some specimens may possibly be found to branch from a common trunk with it . It courses out ward and upward , dividing into two branches near the proximal

on e of end of the penis . The dorsal these branches passes to the of dorsal retractor the penis sheath , the ventral subdivisi on gives off a twig which anastomoses with a branch of the third cerebral of nerve , another to the ventral retractor the penis Sheath , and off then courses forward below the penis to its distal end , giving of several minute branches to it . The extreme ramiﬁcations this portion of the nerve are to the anterior end of the penis sheath i and to the muscles and ntegument surrounding it . Upon the left side this nerve i s distributed t o the muscles and integument of the body wall from the eye forw ard .

Teth s d act lom ela on e In y y these two nerves , numbers and

f T cer v in a n o . o e two , are represented by but nerve, described as on 2 PI I the ﬁrst page 7 , and so ﬁgured in . II , p . , but with the same

as distribution the ﬁrst and second here described . The third pedal nerve ( 3 ) arises from the upper external of margin the ganglion and bifurcates almost immediately . The

on e anterior of these branches divides in turn almost at once, on e a branch , 3 , forming an anastomosis with the first pleural l I nerve (p . ) , being like it distributed to the dorsal peritoneum to r b and musculature back the hea t region , the other , 3 , passing directly backward to a similar distribution . The posterior main of branch ( 3 c ) is much longer and is Shown in detail in fig . 35 PI ff b o . . VIII . It curves backward , sends a branch (fig 35 , 3 ) , to of the right lateral retractor muscle the head , and to the body wall TETHYS CERVINA DALL A N D SIMPSON 49

f Boh adsch or . c O o above it , another ( fig 35 , 3 ) , to the rgan , hypobranchial gland , and finally (fig . 35 , 3f) , unites with the

ﬁrst nerve from the right parietal ganglion , thus forming a

- parieto pedal connective . From the above mentioned branch b of ( ﬁg . 35 , 3 ) , to the lateral retractor the head a branch is given off which courses backward along the body wall , passes beneath

of Boh adsch the right margin of the Organ , and well beyond the latter forms an anastomosis at an acute angle with the recurrent

2 c of . l . v of branch (ﬁg . 35 , ) the second nerve ( ﬁg 35 , . the le t f visceral ganglion , which also sends a branch to the Organ

h Teth s d act lom ela of Boh adsc w . , as will be described belo In y y the third pedal nerve is represented by two separate nerves , the of 2 8 second and third the description on page , they correspond

of T c er v i n a ing in their distribution to the third nerve alone . .

is m The fourth pedal nerve ( 4 ) long and slender, arising fro the outer margi n of the ganglion and passing backward to the parapodium of the same side . The ﬁfth pedal nerve ( 5 ) is a strong on e from the median ff lateral margin of the ganglion . Close to its origin it gives o a slender branch ( 5 a ) which might possibly be considered a separate

i s n nerve , though its distribution the same as that of the mai T d act lom ela nerve , to the parapodium . In . y a similar branch off o is given fr m the ﬁfth nerve , but its origin is further removed of from the base that nerve . Its distribution is the same as that here indicated .

or l 6 f The sixth , posterior peda nerve ( ) is the longest o the

‘ th e edal — nerves from p ganglion . It arises from the mid lateral of margin the ganglion , curves backward , unbranched for over on e- of it s half course , and is distributed to the posterior portion of the foot . The seventh pedal nerve ( 7) arises upon the lower portion of - of i of the ventro anterior face the ganglion , below the orig n the ﬁrst and second nerves . Like these and the ninth is is closely imbedded in the connective tissue surrounding the pharyngeal ou t f bulb and may be dissected with some di ﬁculty . A branch of

ar the seventh forms an anastomosis with the ninth , and both e of distributed to the muscles and integument the side of the head . of The ner ves both sides are alike in origin and distribution . or 8 The eighth, median pedal nerve ( ) is a strong trunk 50 OPISTHOBRANCHIATA OF BRAZIL

arising from the outer lower margi n of the ganglion and is dis i f tributed to the middle reg on o the foot . Upon the left side its of origin is slightly more removed from that the tenth . The ninth pedal nerve ( 9) arises from the ventral portion of f the lower anterior face o the ganglion . It is quite slender and

of dist r i forms an anastomosis with a branch the seventh . Its b u t ion has been given above in connection with that of the latter

on . nerve , and is similar both sides

The tenth , or anterior pedal nerve is a large trunk

from the outer lower margin of the ganglion . It doubles forward in four main divisions beneath the pharyngeal bulb and is dis

tributed to the anterior portion of the foot . of The order , arrangement and distribution the pedal nerves of Teth s i s the same for the two species y here studied , but they

disagree markedly with the accounts given by other authors , notably Von I h er i n g and Maz zar elli for the Medi t o terranean forms . Until I am able secure material for a de tailed comparison of all the species concerned I cannot explain

f on I h er i n this lack o agreement . V g describes and ﬁgures

ix Maz zar elli but s nerves from each ganglion . describes and ﬁgures seven paired pedal nerves and on e unpaired on e upon t w o the right side , and unpaired ones upon the left , thei r order

n ot and distribution agreeing with the Brazilian forms , while

—D u th i er s s ix Lacaze found but in all .

P r l n lia l leu a ga g . The pleural ganglia (p . are situated j ust above and in contact with the upper surface of the pedal

w 1th ganglia , which they are connected by the very short pleuro

on e- of pedal connectives . They are about third the size the pedal

ganglia , and are spheroidal in outline, measuring mm . in

greatest diameter . They are made up of large conspicuous cells , which give their surface a knobbed appearance . Contrary to the descriptions and ﬁgures of Von I h er in g and Maz z ar elli I ﬁnd that the pleural ganglia give rise to the following nerves .

Pl u r al n e er v es . From the left pleural ganglion arise t w o l I . i s nerves The ﬁrst (p . ) , a slender nerve from the superior

face of the ganglion . It passes outward and downward , receives an anastomosing branch from the third pedal nerve and r am iﬁ es TETHYS CERVINA DALL A N D SIMPSON SI

of to the peritoneum and the muscles the dorsal body wall , j ust above and behind the region of the central nervous system . l The second pleural nerve ( p . arises j ust exterior to the

- origin of the pleuro visceral connective . It passes backward as a long slender unbranched trunk in the dorsal peritoneum , to the

of r am iﬁ es region the pericardium , in the anterior wall of which it among the muscles .

l . I From the right pleural ganglion but one nerve ( p ) , i s ff t o on e of given o . It corresponds the ﬁrst the left side and has a similar distribution . It also receives an anastomosing branch , f a o . 3 , from the third pedal nerve the right side From the median posterior face of the ganglia arise the long and strong connectives , which pass backward to the ganglion com plex upon the visceral loop , situated immediately below the of anterior boundary of the pericardium . The left these connect

l v it s i ves (p . . is slightly longer than fellow , measuring for of as . . mm . , compared with mm that the right side

l ar - The right of these (p . p . is the pleuro parietal connect

- ive , the left the pleuro visceral one . Their peripheral relations

n will be taken up further o .

B u ccal an lia g g . The buccal ganglia are oval in outline , each measuring mm . in length by mm . in width , and

. t are connected by a broad commissure mm in leng h , so that tw o the ganglia are distinctly separated from each other, though enveloped in a common connective tissue sheath . From the anterior median face is given Off a strong unpaired ne r ve as in Teth s dact lom ela to of y y , soon bifurcating the muscles the rotella . of off From the outer side each ganglion four nerves are given ,

- in addition to the cerebro buccal commissures . These nerves are r dist ibuted to the pharyngeal bulb , the salivary glands and the

n ot ou t esophagus , but their ramiﬁcations were worked in detail .

Par i eto- v is cer al an lia - g g . The parieto visceral ganglion PI a r v . group ( . VIII , ﬁg . 35 , p . is situated beneath the dorsal of of wall the body , slightly to the right the median line and of directly below the anterior border the pericardium . The com of of position the group as made up a right and left portion ,

ou t fused in the median plane, can be readily made , but any further division into component ganglia is not indicated in surface n view . The double ature of the group is marked only at the 52 OPISTHOBRANCHIATA OF BRAZIL

of anterior end by the entrance the respective connectives , and of by a slight groove upon the anterior face . The nerve cells these ganglia are of the usual gigantic type found in Opistho branchs generally, and cause the surface of the ganglia to present a series of irregular protuberances . P r tal n er e or a i e v s . From the right parietal ganglion arise two nerves . I 1 . . . . 2 r . . . The vulvar nerve ( Pl VIII , ﬁg 35 Pl X , ﬁg 4 , p ) ,

r is a delicate t unk from the right side , soon bifurcating into ( a ) ,

2 r . I a a branch ( ﬁgs . 35 , 4 , p . ) coursing forward and anastomos ing with a branch of the third pedal nerve ( Pl . VIII , ﬁg . 35 , 3f ) ,

- forming the pedo parietal connective before described , and ( b ) ,

r . . . . 2 r . . I b the vulvar ne ve proper ( Pl VIII , ﬁg 35 ; Pl X , ﬁg 4 , p ) , which passes to the anterior end of the large hermaphroditic duct and to the integument surrounding it .

- 2 os h r adio . . . The second , or p ctenidial nerve ( Pl VIII , ﬁg 35

2 r . . Pl . X , ﬁg . 4 , p is a very strong trunk, in diameter quite

- reaching that of the pleuro parietal connective . It arises from of the upper right side the parietal ganglion , passes outward and

r backward in a cu ve to the right , thence upward to the anterior of base of the ctenidium , where it unites with the large ganglion 2 os the osphradium ( Pl . VI II , ﬁg . 35 ; Pl . X , ﬁg . 4 , p . lying immediately below the integument , and visible through it . The osphradium is visible externally as a depressed oval area of a light yellowish color , situated upon the ventral face of the anterior of b portion the base of the ctenidium . It is mm . in lengt h y

‘ th i s os h r adial mm . in width . From p ganglion arise two rather

on e . . . . 2 os . . I strong nerves , ( Pl VIII , ﬁg 35 ; Pl X , ﬁg 4 , p g ) ,

n passing forward , its several branches being distributed amo g the of large gland cells the anterior and lateral margins of the mantle . The other nerve from the osphradial ganglion passes a short dis tance to the left and terminates in a smaller branchial ganglion

2 ct of ( Pl . X , ﬁg . 4 , . g . ) at the right the pericardium . From this 2 t r c . ganglion a main branchial ne ve ( Pl . X , ﬁg . 4 , passes backward to the ctenidium , and several very delicate nerves are also given off to the pericardial wall and are lost among its

ﬁbres .

isc r al n V e er v es . or The left , visceral ganglion is equal in

on e. size to the right parietal At its anterior, more pointed end it

54 OPISTHOBRANCHIATA OF BRAZIL

8 of l . and Tethys d epi a/ns as typical of his results In ﬁgs . 3 and 39 the same plate I have made similar diagrams showing the innerva

Teth s d act lom ela Teth s cer v i na tion for y y and y , according to my Teth s dissections . Vayssiere describes and ﬁgures for y ” d e ilans of p a branch the nerf genital , which originates from the l e t r i h t f visceral ganglion ( not from the g , as quoted by Mazza ! ” lli or of r e . , p and passes to the glande opaline , gland B h h H o adsc . e , as in the forms here described does not ﬁnd , how

Mazz ar elli ever, the innervation from the pedal ganglion also . of of disputes the accuracy the observations Vayss i ere , holding Teth s that the nerve supply is from the pedal ganglion alone . In y d actylom ela and Tethys cer v i n a we have seen that both ganglia of Boh adsch in question send nerves to the Organ , so in these

n ot forms both authors would be partly right , and it would be a of of matter great surprise to ﬁnd , upon a reexamination the Mediterranean Aplysiidae that in them also the double innerva tion actually exists .

2 l v 3 . The third nerve ( Pl . VIII , fig . 35 ; Pl . X , fig . 4 , . . arises from the posterior margin of the left visceral ganglion and off courses backward , giving a slender branch to the liver, crosses the large hermaphroditic duct near its origin , sending a delicate branch to it , swells into the small genital ganglion , ( Pl . VIII , fig . t of 35 , g lying at the base the adnexed genital mass , and thence passes backward parallel to the small he r maphroditic duct

on e- for nearly half the lengt h of the latter . To this duct it sends v a a branch ( Pl . VIII , ﬁg . 35 , . 3 ) , which passes backward along

its surface to the ovotestis , sending a few delicate branches to the

. . v . b duct on the way The main trunk ( Pl . VIII , ﬁg 35 , 3 ) , turns t o abruptly the right , leaving the hermaphroditic duct and , passing r am iﬁ es of backward , in the dorsal body wall in front the anal of portion the alimentary canal .

. . 2 l v 4 The fourth nerve ( Pl . VIII , ﬁg 35 ; Pl . X , ﬁg . 4 , . . equal in size to the second and thi rd , arises at the posterior end of t o the ganglion , close to the base of the third nerve , diverges the left, sending a branch to the liver , and courses obliquely across o below the pericardium to its posteri r wall . A strong branch

. ff of . a o ( Pl VIII , fig 35 , 4 ) , is sent about midway this course r am ifi es t o n which the ventricle and the pericardial wall , the mai b trunk, ( Pl . VIII , fig . 35 , 4 ) , curving dorsally in the posterior TETHYS CERVINA DALL A N D SIMPSON 55

wall of the pericardium , bifurcates to the kidney, the dorsal peri cardial wall and the auricle near the entrance of the branchial vein . In Tethys dactylom ela and in the Mediterranean Aplysiidae n 10 8 t studied by Maz z ar elli Mo og . p . ) the third and four h f or Teth s cer v in a nerves , here described as separate y , are united in on e trunk for some distance from their origin .

E TH REPRODUCTIVE SYSTEM .

t ov . The ovotestis ( Pl . VI , ﬁg . 33 , . ) is an irregular lobulate of organ , situated at the posterior end the visceral mass , closely t o united the liver in front , and inclosed in the last turns of the

- intestine . From its median antero dorsal face the small herma

m h . d . h r oditic . . s . p duct ( Pl VI , ﬁg 33 , ) arises , a white nearly straight tube , mm . in length , gradually increasing in diameter

as . from mm . it emerges from the ovotestis , to mm near the adnexed genital mass . The adnexed genital mass is a ﬂattened , elliptical complex , made up of the nidamental and albumen glands of and the fertilization chamber, inclosed in the loops the genital c . s . . . S duct , ( ﬁg 33 , p p , and is ituated immediately behind and below the right posterior border of the pericardium . m m It is mm . in length , mm . in greatest width , and . in

I ts thickness . position is in almost direct prolongation of the large hermaphroditic duct , which extends forward along the right of body wall to the external opening . At the left its basal end

s . c . the spermatocyst ( Pl . VI , ﬁg . 33 , p ) proj ects transversely as

- t on e - a free pear shaped sack , its leng h , mm . , being half the

t of e it s i s leng h the adn xed genital mass , while diameter nearly t ! d . C I s . f 0 . . . . o 5 mm duct ( Pl VI , ﬁg 33 , ) the duct Cuvier ,

Opens into the proximal end of the copulatory duct ( Pl . VI , ﬁg . 33 ,

c o . p . The stout large hermaphroditic duct is 4 5 mm . in

on e- of its length , half that the small hermaphroditic duct, diam

eter mm . being practically the same throughout . It is made of of up two channels , separated by deep folds the dorsal and

ventral walls , which overlap in the median line thus forming the

- . v d ov o . o . s . . spermatic duct ( Pl VI , ﬁg 33 , p ) and the Copulatory

co it s duct ( Pl . VI , ﬁg . 33 , p. At distal end it i s slightly enlarged and receives the long slender duct of the vesicle of

Swammerdam , the spermatotheca , ( Pl . VI , ﬁg . 33 , which

e l s . i s nters from the eft ide and above This duct mm . long 56 OPISTHOBRANCHIATA OF BRAZIL

and mm . in diameter . The spermatotheca is thin walled , spherical and mm . in diameter . A very slightly developed of system folds in the wall of the large hermaphroditic duct , close to and above its external opening, probably functions as a vulvar gland . The spermatic portion of the duct is continued for ward beyond the external Opening as a deep groove along the side of sit the animal , downward and forward , to the penis opening, t d of u a e as usual on the right side the head , j ust below the

ev er t ible anterior tentacle . The penis is inclosed in an , muscular of sack , the posterior end which is attached to the foot and the of lower body wall by two groups retractor muscles , a dorsal and m a ventral set . The sper atic groove is continued along the inner of wall this sheath to its base, where the penis proper is attached , and is thence continued forward along the side of that organ to its tip . In its retracted condition the penis sack measures mm . I t s of inner wall is thrown into a series longitudinal folds , between th e two of which the spermatic groove is inclosed . This and adj acent folds are sprinkled with brown pigment . The proximal end of the sheath i s occupied by the retracted i n penis , a slightly ﬂattened , conical , muscular organ , mm . diameter at the base, and ca . mm . long in its retracted con dition . Along its whole length extends a deep furrow , the spermatic groove , continuous at its base with the groove upon the N O o of inner surface of its sheath . trace can be made u t any of or armature upon any portion the penis its sheath , nor is there n a y specialized glandular area present .

HE B HA D T ORGAN OF O SC H .

of Boh adsch or r The organ , hypobranchial gland, is sphe ical , of somewhat ﬂattened in form , a whitish color , and has a diameter of mm . In general aspect it presents the appearance of a of close bunch grapes , its surface being nodular in form , corre s on di n of is p g to the very large gland cells which it constituted .

The gland Opens externally by a single large duct , the oriﬁce with tumid margins being situated upon a conspicuous elevation

O below the ctenidium and behind the reproductive pening . Large gland cells similar in form to those of the hypo i n branchial gland are also found scattered the mantle margin , TETHYS CERVINA DALL A N D SIMPSON 57 and doubtless contribute to the well known characteristic de of fensive secretion these animals .

CIRCULATORY, EXCRETORY AND RESPIRATORY SYSTEMS .

of Teth s The circulatory , excretory and respiratory systems y cer v in a so n ot f , far as studied , were found to di fer markedly from of of those other species , and matters familiar knowledge , and hence they will not be entered upon in this place .

Leland Stanford Junior Zoological Museum, Invertebrate 1 Series No . 44 . PLEUROBRA N CHOI DEA . TRIBE III .

- or Dorsal region covered by a large shield like mantle, H S or . notaeum . hell external , internal absent ead distinct , with f on two pai rs o tentacles . A single ctenidium the right side ,

between the mantle and foot . Foot without parapodia . Genital

duct diaulic, the male and female apertures contiguous . Visceral

commissure short .

l R BRA HI D A E Fam i y PL EU O N C .

f or Mantle ﬂeshy, sti fened by spicules , concealing wholly

h alioti for m . partly the delicate shell , if developed at all Anterior

. or tentacles united to form a frontal veil , posterior tentacles ,

in h r r h o o es . p , auriculate . Foot ﬂattened , large Radula multiserial ,

r h ach i dian with no teeth . Mandibles well developed , composed of many oblong plates arranged in tesselated pattern .

‘ en L B A H v e 1805 G u s P EU RO R N C U S Cu . i r,

Pleu r obr an ch u s su r Ph llidi e et su r le , Cuvier . . Mémoire la y ’ du d Hi st oi r Pleurobranche . Annales Museum e Na

t u r ell 1 - 1 - e 80 . 2 66 2 6 P 18 1 6 , V, 5 , p 7 , . , Figs . . B er th ella . 182 . 62 . 6 , Blainville Manuel de Malacologie 5 , p 4 9, 7 , 1 Pl . XLIII , Fig . . ’ Pl eu r obr an ch u s Pilsb r . of , y Tryon s Manual Conchology, XVI , 18 6 1 1 9 , p . 9 .

Pleu r obr an ch u s a ss1er e l V . P eu r ob r an ch idés , y Monographie des .

. S S er 8 Ann des ciences Naturelles , Zoologie . . , T . VIII , 18 8 2 9 , p . 79.

Pleu r obr an ch u s Mal ol i h . ac o sc , Bergh g e Untersuchungen , IV. ’ 1 S em er s im , 3 , in p Reisen Archipel der Philippinen, 18 8 1 1 VII , 9 , p . 7 .

or its Body elliptical , mantle more less developed , borders or free , the anterior border more less emarginate ; shell internal , or calcareous subcalcareous . Rhachis of ctenidium smooth . Male or and female genital openings contiguous , almost united . Mandi

of e set bles made up ﬂatten d, closely elements . PLEU ROBRA N CHU S A G A SSI ZI I MA C FARLAND 59

iz ii v n h as s o . Pl eur ob r a c u s ag Sp . N

43 - 57. a es I an d I I s . Pl t X X , Fi g

Three small specimens of a Pleu r ob r an ch u s were taken by

D . M r . Greeley at Riacho oce , Alagoas They were killed in

formalin and afterward transferred to alcohol . The coloration of the animals in life was not noted ; the color of the preserved of specimens is a rather uniform pale, pinkish yellow . In two the specimens a ﬁne light brown mottling seemed to divide the dorsum

into very minute polygonal areas , but even this trace of color

gradually disappeared on their being transferred to alcohol .

EXTERNAL CHARACTERS .

i e 10 1 1 8 . S z . The three individuals measured , and mm in

t 6 6 . total leng h , by , . 5 and mm . in width respectively In each s o case the foot is somewhat contracted , the mantle but slightly ,

the measurements in life probably exceeding the above somewhat .

f 6 . . t o . The leng h the foot is 5 , and 5 5 mm , with corresponding

widths of and mm . in each case . B d m o or . y f The body is arched , slightly depressed , oblong ; it s the mantle broad , extending far beyond the foot throughout entire circumference , though the strongly contracted posterior

r h in o h or es end of the foot , the p , and the frontal veil probably extend well beyond the mantle margin in the living animal . The mantle margin is very slightly emarginate above the tail . The surface of the dorsum is smooth , save for slight , i rregular nodo sities formed by - unequal contraction . The mantle margin is mm moderately thick and very wide , being . in width , its free edge being smooth . ll ﬁ S h e . . The white calcareous shell ( Pl XI , g. 4 3 ) shows plainly through the mantle in all the specimens . It is placed well forward , its anterior margin being above the head region , while the posterior portion covers the anterior two- thirds of the poste rior visceral mass . In outline it is oblong, nearly linear, the lateral margins being nearly parallel . The anterior margin is

r more gently rounded than the posterior one , the spire ve y small , t w o oblique, the whole shell being made up of about turns , the

on e outermost very broad and ﬂat, and forming almost the whole of of area the shell . The lines growth are plainly marked ; the 60 OPISTHOBRANCHIATA OF BRAZIL

inner and outer surfaces of the shell are quite smooth . The length of the shell varies in the three specimens from mm . to

. mm . , its width from mm . to mm

Foot . The foot is smooth , truncately rounded in front, more pointed behind . No well marked pedal gland is visible at its of posterior end . The lateral margins the foot are continuous , undulating, the anterior margin bilabiate , the lower lip much thicker than the upper, which bears a median notch . The dorsal of m surface the foot margin is smooth , with no visible pig enta tion , i f any existed during life . d Hea . The frontal veil is large, trapezoidal , its anterior, free margin smooth , nearly straight , the outer angles very slightly of rounded , the external margin deeply auriculate . The width the frontal veil in the three specimens is and mm . r h in o h or es respectively, the length being mm . in all . The p

c lin d r o- ( Pl . XII , ﬁg . 57) are very large y conical organs , their of bases contiguous , but not fused . Each is made up a loosely on e rolled plate, the margins external , the lower overlapping the upper . The margins are prolonged at the base into a considerable

ﬂap , which is free . Just above and external to the base the very large eyes shine conspicuously through the integument . t i i on C en d u m . The branchial plume lies the right side in the roomy space between foot and mantle, completely concealed

- f . t o by the latter It measures one half the total leng h the body, being mm . long in the largest specimen , while in the smallest

- on e . . . on e t it is but mm , i e fourth the body leng h . The posterior half of the plume is free from the body wall ; the rhachis entirely smooth . The plume is bipinnate , bearing about

on twelve pinnules each side , arranged alternately . The anal Opening is situated above the posterior end of the base of the branchial plume .

INTERNAL ANATOMY .

Man i e d bl s . The labial armature is made up of a pair of of oblong mandibles a light amber color in their anterior portion , f becoming paler behind , borne upon the sides o the buccal Open

. t ing Their greatest leng h i s mm . , their width mm . , being nearly twice as long as wide . The oblique anterior border

on dor is slightly narrower than the more rounded posterior e, the

62 OPISTHOBRANCHIATA OF BRAZIL

R adu la Th l on e on e . e radula is nearly color ess, about and s i s half times as long a broad . The rhachis narrow and naked ,

the lateral teeth are unciform , strongly hooked , and arranged

8 2 t o 0 . in 4 rows , with from 4 5 teeth in each half row The dental

- X formula may hence be expressed as 4 2 50 :0 :4 2 5O 4 S. The inner

i n r ow . . 2 most tooth each ( Pl XI , fig 5 ) is somewhat smaller of than its neighbors , the remaining teeth being approximately of the same size, with the exception the outermost ones , which of m decrease gradually in size , the last ones the series beco ing r of flattened and almost rudimenta y ( Pl . XI , fig . The body

0 - 2 each tooth ( Pl . XI , ﬁgs . 5 5 ) is oblong, ﬂattened , slightly or oblique, its posterior end truncate, in some cases emarginate

notched . The anterior end is rounded , the inner margin expanded

into a ﬂattened wing, which is overlapped by the next inner

tooth , the outer margin being nearly straight . Viewed from below of b ecom ( Pl . XI , ﬁg . 53 ) the bases are a somewhat oval outline ,

ing more linear toward the ends of the rows . A typical tooth ,

P1 . 0 on e . such as the shown in side view in XI , ﬁg 5 , taken from f 22 o d . the middle the row , measures mm in total length of of of base, the height the hook above the bottom the base is of mm . The outermost tooth , such as is shown i n ﬁg . 49, PI h . 1 1t . XI , taken from the row , is mm in base length , its

total height being mm . Vis cer a of . The very poor preservation the viscera pre of cluded any satisfactory study their structure and relations , thei r hard and brittle condition resisting all attempts at softening .

NERVOUS S YSTEM .

Cen tr al an li a g g . The central nervous system is enveloped

in a closely ﬁtting connective tissue capsule , very difﬁcult to remove , which also binds it closely to the buccal mass . The

- cerebro pleural complex ( Pl . XII , ﬁg . 55 ) is closely fused , and the two sides are in such close contact in the median line that no ou t commissures connecting them may be made . No distinct line of demarcation can be made out between the cerebral and of is an pleural moieties the complex upon either side, nor there y of grouping the nerve cells to correspond to such a division . The separation into two distinct ganglia as Shown by Von I h er in Pl . m eck eli 8 g for ( ﬁg . , Taf . does not here PLEUROBRA N CHU S A GA SSI ZI I MA C FARLAND 63

obtain , the two ganglia being united into a single ﬂattened mass ,

of . circular in outline , and having a diameter mm The

- pedal ganglia are slightly smaller than the cerebro pleural ones , being mm . in diameter , and having the same ﬂattened , st r u c spherical form . The eyes are very large , nearly spherical tures , mm . in diameter, and borne upon very short optic nerves . on n cti — — C e v es . The cerebro pedal and pleuro pedal connectives c con l con ( Pl . XII , ﬁg . 55 , . p . . , p . p . . ) are extremely short and can only be seen after carefully dissecting away the capsule and dis placing the ganglia by gentle pressure upon the cover glass .

toc s PI O ts . y . The otocysts , not represented in ﬁg . 55 of XII , are spherical structures , mm . in diameter . They are situated of of at the upper inner border the inner face the pedal ganglia ,

- close to the cerebro pedal connectives , and contain a large num of ber minute otoconia .

REPRODUCTIVE SYSTE M .

The glans penis is extruded in all three specimens . It is

Short and bluntly conical , and is surrounded at its base by a con s icu ou s of p fold integument , which is continuous all around save at the posterior side , where its ends overlap with a deep ﬁssure

between them . Just within this ﬁssure , and close to the posterior portion of the base of the glans penis is the female opening ( Pl .

v . XI , ﬁg . 54 , ) The exact relations of this opening with that of the duct of the nidamental - albumen gland could not be made ou t ; satisfactorily They are very close together , the gland duct seeming to have a common external opening with the vagina , but the condition of the material made this and other points in the structure of the reproductive system uncertain . In sections the glans penis is circular , and there is no indication of an

- anterior wing like appendage , such as is g iven by Vayssiere as a h t r Mon o of Pleu r ob r an c u s 3 s . . characteristic his subgenus . ( g ’ 8 0 9 . p - 3 7)

SYSTEMATIC POSITION . There can be no doubt but that this species is distinct from the three Antillean forms described by MOr ch especially in the light of the careful anatomical description which Bergh 64 OPISTHOBRANCHIATA OF BRAZIL

’ 98b ) has given of these forms . Its lack of agreement ’ Pleu r obr an ch u s ata on i cu s d O r bi n with p g g y , the only recorded of species from the east coast South America , is equally clear from Bergh ’ s study of the anatomy of that species Nor does it agree satisfactorily with the Antillean Pl eu r obr an ch u s lacteu s of D 6 xt all and Simpson p . 3 7) in e ernal characters nor in of be shell . An anatomical study the latter species is much to desired , however, before certainty can be assured . In the mean time I must consider the present form a new species and have much pleasure in dedicating it to Professor Alexander Agassiz H of arvard University .

. 1 S Type No 4 5 , Invertebrate S eries , Leland tanford Junior

University Zoological Museum . D H SUBORDER NU IBRANC IATA .

Naked hermaphroditic Opisthobranchiate Mollusca , gener

of - ally symmetrical , slug like form ; without a shell in the adult

state . Ctenidium and Osphradium absent ; symmetrical accessory respirato r y appendages usually developed from the dorsal i n tegu ment , rarely from the sides . Central nervous system concentrated . or K Radula usually strong, the teeth uni multiserial . idney not

compact .

D RI D I DEA O O . TRIBE I .

t r iau lic Genital duct , liver completely inclosed in the visceral

- mass , female duct bifurcated . Anal aperture postero median

or upon the dorsum , surrounded by the branchial rosette, rarely

er i n otaeu m between the p and the foot .

F l I D I am i y D OR D AE .

ar e or Branchial plumes in an circle , usually j oined together ~ at their bases , usually retractile into a common cavity . Rhino h or es p always with perfoliate clavus . Pharyngeal bulb never suctorial .

D I D R I D I N A E Subfam ily SCO O .

n ot r an u Body hard , depressed ; the dorsum minutely g li er ou s g . Mantle margin rather wide ; tentacles digitiform ;

r branchial plumes usually tri o quadripinnate foot rather wide . of set Labial armature made up minute , closely rods . Rha f o a . chis radula naked , the pleurae multident te , the teeth hooked

Penis usually unarmed .

of D Three Specimens orididae were found in the collection , of e all them being apparently new speci s . G en u s D I SC O D O RI S B e h 1877. , rg ,

h r b ii ch er Malak oz oo is cod or i s . a D , Bergh J der deutschen — M l olo i h 18 . 6 1 . a ac sc e logischen Gesellschaft , IV , 77, p g — 8. . . 18 . 1 Untersuchungen , XII , 77 , p 5 Mal Unters — H . S 188 6 8. . XV, 4 , p . 5 Mal Unters upplement eft I , — 18 0 8. . . 881 . 10 1880 . : 1 , p 47 II , , p Mal Unters XVII , 9 , — 8 S N u dib r an ch i at en G aster o od en . p . 95 ystem der p — t 188 . 2 . 18 2 . 10 2 . 9 , p Challenger Repor s , X , 4 , p 9 — i 1 0 b o a . D i e Opisthobranchiata der S g Expedition 9 5 , 8 p . 9 .

or Body rather soft , rounded oval in outline ; branchial or aperture slightly crenulate , stellate bilabiate ; the anterior mar

f o or . gin o the foot bilabiate , the upper lip m re less notched

Prostate gland large .

i e D i s cod or s b r an n r i Sp . N ov .

l a ﬁ s 58- 65 e I I . P t X , g .

of D c One specimen this form was taken at Riacho o e ,

Alagoas , and was preserved in formalin , followed by alcohol .

r h n h or The i op es and branchiae are completely retracted , the whole specimen being slightly contracted and rolled up . No notes accompanied it save that of locality alone .

EXTERNAL CHARACTERS .

F o o l r . or m . C The body is depressed , linear oblong with b lu n tly . r ou n ded anterior and posterior ends . The dorsum is minutely villous , being everywhere covered with minute conical papillae . The mantle edge is thin and broad , extending far

o on e- beyond the margin of the f ot, and is fully half the width of the latter in the preserved specimen . The general ground of color the dorsum is pinkish , with thickly scattered irregular of blotches brown everywhere over its surface . Along the sides of the dorsum i s a longitudinal r ow of ﬁve or six larger black

Spots about equidistant from each other . F ot o . its The foot is smooth , almost linear, anterior and posterior ends bluntly rounded . The anterior margin of the foot is thickened , and deeply bilabiate, the upper lip bilobed by PLEU ROBRA N CHU S A G A SSI ZI I MA C FARLAND 67

a deep median notch . Its length is mm . , the width mm . of The ground color the foot is pinkish , thickly set with irregular brownish blotches , apparently arranged at random , i . e . producing no deﬁnite color pattern . The largest of these blotches may reach a diameter of mm . , but the maj ority are much smaller .

Head . The head is retracted and bears two tapering 2 conical oral tentacles , . 5 mm . long, and with a basal diameter Of

mm . i n o or r h i n o h or es R h ph es . The p are completely retracted within their sheaths , the margins of which are low and closely s et with short slender papillae . The clavus of the rhinophore is stout, club shaped , and lamellate .

B r n c i ae a h . The branchiae are situated as usual upon the — posterior mid dorsal region , surrounding the anal papilla and the

s ix renal Opening . They are in number, tripinnate , and retractile m within a deep branchial pocket , the argin of which is thin and slightly prominent . t a of . Tot l leng h the specimen mm , its width mm .

INTERNAL ANATOMY .

O f The dorsal wall the body cavity is rather ﬁrm and thick, it s peritoneal lining colorless , save for a pinkish tint, which is possessed by all the viscera in common .

ALIMENTARY SYSTEM .

The alimentary canal is of the general type of the crypto

D or i ds . branchiate The pharyngeal bulb is conical , truncate in

lOn 2 . front, mm . g, by 5 mm . wide, and mm . in height , the

radula sheath proj ecting behind and below as a rounded eminence . of The mouth Opening is an inverted T shape, the labial disc being covered by a ﬁrm transparent cuticle .

L abial ar matu r e on . Externally the opening is guarded

u either side by a somewhat triang lar , yellow plate , the apex of

which is directed backward ( Pl . XII , ﬁg . The anterior of of border each these labial plates is slightly convex , ca . mm .

long, the upper border is straight, mm . long, and is separated from its fellow on the opposite side by a distance of from to

. e mm The posterior bord r is very Slightly concave, mm .

in length , while the lower angle is rounded . 68 OPISTHOBRANCHIATA OF BRAZIL

These mandibular plates are made up of slender closely set r odlet s blunt , longest in front and decreasing in length toward r the posterior border . Those of the anterior po tion range up to I P . u mm . in length ( . XII , ﬁg and decrease reg larly toward the posterior portion , where they are very short ( Pl . XII , f ﬁg . the average diameter o ca . mm . remaining nearly r odlet s the same throughout , the tips of the being slightly dilated to nearly the same extent also .

R ad u la i s . The radula broad and short , deeply grooved

of on e longitudinally in the median line , the teeth sort , uniform 2 6 in shape , strongly hooked , and arranged in rows of from 4 5

8 r ow of . to 4 teeth in each half , the rhachis being destitute teeth

- X 2 The dental formula may hence be expressed as 4 5 4 8 6 . 62 The outermost two or three teeth of each row ( Pl . XII , ﬁg . ) of are slightly smaller than the remaining teeth the row , the base of the outermost being about on e- third the lengt h of that of the of others , the remaining teeth being practically the same size tw o until the innermost are reached , which are again somewhat

of . 6 smaller . The average height a typical tooth ( Pl . XII , ﬁg 3 ) f . t o is mm , the leng h the base mm . The general tint of the radula is a faint yellow , deepening posteriorly , while the s o anterior portion is colorless or nearly . B l d l oo an d . g Overlying the buccal mass is the blood gland , l divided into two lobes , the argest being thick and rounded , about

mm . in diameter , and is situated in front of, and in contact with the central nervous system . The posterior lobe , immediately u behind the anterior one , is much smaller, triang lar in form , its

’ f o ar an d r w d t of . base being directed , has a leng h mm and of a breadth mm . at the broadest end .

li l n d - S a v ar a s . y g The salivary glands are long and strap like , the anterior portion , mm . in width , being coiled upon the

0 . posterior face of the pharyngeal bulb . Each narrows to . 5 mm in width as it passes through the nerve collar , and extends back

- ward , below the viscera ventrally , for about one half the total length of the animal .

Es o u s tom an d i n t ti n e h a s ach es . p g , The esophagus is short

1 . and wide, ca . mm . long by . 5 mm in diameter , passing directly

downward and backward to the stomach , into which it dilates . The latter organ lies i n a deep notch in the anterior face of the

70 OPISTHOBRANCHIATA OF BRAZIL

it s . mm . , greatest breadth mm and thickness mm . Its surface is very ﬁnely lobulated .

e er en an d n i v as Vas d f s p e s . The deferens courses straight forward and outward along the inner and anterior faces of the n t complex to the pe is . Throughout its whole leng h it preserves of a uniform diameter mm . , dilating suddenly at its outer n end into the pe i s . The penis is somewhat contracted and nearly spherical in form , about mm . in diameter, the large conical 6 glans ( Pl . XII , ﬁg . 5 , p . ) proj ecting externally . The latter is bluntly conical , its apex truncate , mm . in length , mm . in

0 . diameter at the base , and tapering to 5 mm . at the apex . The of s et glans bears an armature minute hooks , in longitudinal 1 of rows , about 7 in number near the distal end the glans and 10 0 increasing to nearly toward the base . The individual hooks 6 a b ( Pl . XII , ﬁg . 4 , , ) are rather stout , the largest occurring near of the base the glans , and measuring to mm . in height , their basal dimensions being nearly the same .

a i n a an d d u ct V g . The vagina and vaginal duct lie upon the of upper anterior border the anterior genital complex ( Pl . XII , 6 m of fig . 5 , g ) , and are about equal length . The distal vaginal of portion is conical , thick walled , with a series longitudinal ridges it s w upon external surface , separated by shallo grooves , united at intervals transversely, giving the surface a somewhat lobulated appearance , which i s due to internal glandular structures . In sections through the vagina and its duct the wall is seen to be on e con made up of two conspicuous layers , an outer muscular , of sisting mainly of fibres arranged in a circular direction , and n of nearly uniform thick ess , throughout the whole length the vagina and its duct , varying but slightly from about mm . An inconspicuous submucous layer of connective tissue bears of the innermost coat , the mucous layer, which is made up a of layer columnar epithelial cells , distended with secretion prod t s u c . This mucous layer is thrown into closely crowded leaf like longitudinal folds , about twenty in number in the proximal portion of the vagina , and increasing to some fifty or more in the distal extremity . These folds range in height from mm . to mm . in the proximal and distal portions respectively . The i narrow central lumen , left free from the folds , s filled with a

u - coag lated mucous like secretion . DI SCODORI S BRA N N ERI M A C FARLAND 7 1

The vaginal duct is whitish , muscular , of nearly uniform

t . . diameter , and mm . in leng h . It describes a loop ( Pl XII , ﬁg returning upon itself and opening into the spermatotheca 6 ( Pl . XII , 5 , which is a conspicuous dark spherical — of structure , mm . in diameter, lying in the mid dorsal region

- the anterior genital complex . Upon its dorso anterior face is of the common opening the vaginal and the uterine ducts , con of cealed by the overlapping proximal end the vagina . The d 6 u . . uterine duct ( Pl . XII , ﬁg . 5 , ) is slightly the more slender of of the two , and passes obliquely forward along the inner face the nidamental gland , beneath the sack like spermatocyst , which of is doubled above it . Near the anterior end the nidamental gland the uterine duct receives the short slender duct of the

- 6 s . c . spermatocyst ( Pl . XII , ﬁg . 5 , p ) an elongated pear shaped

of . . organ a whitish color , mm m length by mm in diameter, and closely packed with spermatozoa . Its slender duct

n - t f is Slightly less than o e half the leng h o the cyst itself .

i n t l n d N d am e al g a . The uterine duct passes into the anterior 6 m m i f . n . a . i ed o . end the nidamental gland ( Pl XII , ﬁg 5 , ately after receiving the duct of the spermatocyst , and at a point n ot far from the entrance of the oviduct , which j oins the anterior end Of the hermaphroditic ampulla to the nidamental gland . In most D orididae the greater portion of the anterior genital complex is made up usually of the nidamental and the albumen glands . In this individual the two glands in question form but a of m m very small portion the whole , being but . in extreme m mm t . leng h by m in width and . in thickness . Thi s proportion may possibly be due to absence of secretory activity

n on - or - of in a breeding season , to non maturity . The surface the nidamental gland i s ﬁnely sculptured with minute ridges and

depressions , is pinkish in color, and opens externally, immediately of below and behind the opening of the vagina , by means a broad 6 . . n t duct ( Pl XII , ﬁg 5 , . mm . in leng h . The albumen

gland is included in the windings of the nidamental gland , being

exposed as a small oval area , mm . in length by mm . in

width , upon the upper face of the larger gland . At the anterior of of border this area is found the entrance the uterine duct . The systematic position of this species presents some dif

ﬁ cu lties - due mainly to the well developed penis armature , a 72 OPISTHOBRANCHIATA OF BRAZIL

i r character not present in the genus D scodo i s . In this respect

Car m i n odor i s f it resembles , from which , however , it dif ers

v el strongly in other features , notably in the granular , almost For v ety notaeum . the present I deem it best to consider it a species of Discodor i s until the study of further material may ff s e warrant a di erent disposition , rather than to create for it a p arate genus based upon this character alone . Some thirty or more species of Di scodor i s have been described , mostly inhabiting the Paciﬁc and Indian oceans . But

u t D i n d cor D n otha D . m a . e a ﬁve of these, . Bergh , Bergh , Bergh ,

D tr is tis D edw ar ds i . Bergh and . Vayssiere are from the Atlantic , the ﬁrst four from the Antilles , the Azores and the Cape Verd

Islands , the last from the Morocco coast . From all these the present species may be distinguished readily . I take great pleasure in dedicating this new species to my esteemed colleague , Professor J . C . Branner, the originator and

- leader of the Branner Agassiz expedition . 6 . 1 S Type No 4 Invertebrate eries , Leland Stanford Junior m University Zoological Museu . is o or i on ih e in D c d s v r gi Sp . N ov .

a s I X I V X ﬁ 6- 6 e V s . 6 7 . Pl t X II , , ; g

of D One specimen this new species was taken at Riacho oce , m 2 0 18 . . acco Alagoas, July , 99, by M r Greeley No color notes an ied p the specimen , which was killed in formalin , afterward

followed by alcohol .

EXTERNAL CHARACTERS

For m elli . The general body form is depressed , elongate , p

tical , the ends equally rounded , the mantle margins rather wide of and thin , proj ecting far beyond the edge the foot , the sub

marginal space nearly equalling the width of the foot itself . Color of i s . The ground color the dorsum pinkish gray ,

or . sprinkled everywhere with minute dark brown , black spots The under surface of the mantle and the sides of the body are a

lighter pinkish , thickly sprinkled with minute dark spots , giving of the surface a dusty appearance . Upon the under surface the mantle on either side is borne a longitudinal series of three t o four large round brownish blotches about midway between the f of mantle edge and the sides o the body . The largest these spots of reaches a diameter mm . Posteriorly this series is continued around above the t op of the foot by a series of six or seven much

smaller spots more irregularly disposed .

D or s u m . The dorsum is rather ﬁrm, tuberculate , being r of covered eve ywhere with low tubercules varying size , inﬂated

at their tips and much thicker than the slender cylin d r o- conical processes covering the dorsum of the preceeding species . The f f o o . largest these tubercules reach a diameter mm , and of occupy the summits slight elevations of the dorsal integument , having smaller and lower tubercules irregularly grouped around them . F o o t . o i s The f ot smooth , rounded in front , its anterior margin deeply bilabiate , the upper lip proj ecting beyond the of of lower , and deeply notched to a depth mm . The sides the foot are nearly parallel , gradually converging posteriorly to

n ot the bluntly rounded tail , which does proj ect beyond the 74 OPISTHOBRANCHIATA OF BRAZIL

mantle edge . The edges of the foot are thin and crenulate . Its color i s in general the same as that of the under surface of the mantle . Head . The head is inconspicuous , the mouth a vertical slit ,

ﬁ n er - bearing upon either side long slender g like oral tentacles ,

mm . in length , their tips blunt and curving forward .

R h in o h or es r h in O h or es p . The p are brownish black, deeply retractile within conspicuous sheaths , with high tuberculate of margins , the tubercules being of the same type as those the

f . . o general dorsal area The sheaths reach a height mm , the whole slightly retracted rhinophore has a height of mm .

of . 2 The clavus is the usual club shape, perfoliate , with ca 5 leaves on each side . The dark pigment is especially concentrated on of the strong stalk the rhinophore , where it forms a circular band , immediately below the clavus .

B r an ch iae . The branchiae are six in number, bipinnate , completely retractile into the branchial pocket , which bears a of conspicuous lobulate margin , the low divisions which carry of tubercules similar to those the dorsum . The anal and renal openings are situated as usual within the circle of the branchiae . The reproductive Openings in the specimen were very small and inconspicuous .

D im en s i on s . t Total leng h of the whole animal mm . ,

. t of its width mm , and maximum height mm . Leng h

. of the foot mm , its width mm . ; greatest width the mantle margin mm .

INTERNAL ANATOMY .

n ds u Blood Gla . The dorsal integ ment is rather soft and

- not thick . The pseudo peritoneum is colorless , save in the region of the central nervous system where it is thickly sprinkled with

minute , dark brown spots . The phagocytic blood glands , two in number lie directly in contact with the central nervous system ;

n the anterior larger o e is elliptical in outline and rather thick, m m 1 . . measuring . 5 mm . in length by in width and mm in

thickness , and is dark gray in color , being sprinkled with minute

black spots . Its dorsal surface is arched , the ventral concave, i while the general contour is smooth throughout . It lies d rectly

in front of the cerebral ganglia upon the pharyngeal bulb . The DI SCODORI S B RA N N ERI MA C FARLAND 75

posterior lobe is very much smaller and thinner , and lies trans v er sel y, its anterior border in contact with the central nervous system . It is somewhat reniform in shape, measuring mm . in transverse by mm . in longitudinal diameter .

ALIMENTARY SYSTEM .

m tu r e L abial ar a . The oral tube is short and conical ,

mm . . in length , bearing a colorless cuticula The labial armature

of . t is small , consisting a median plate , mm in leng h by of mm . in greatest width , and two triangular lateral plates ,

t . . mm . in greatest leng h by mm . in width ( Pl XIII , ﬁg

- The median plate is elongate , spear shaped , and is made up f f of closely s et granular thickenings o the cuticle o varying size . Its median portion is marked by a narrow line in which the thickenings are much less numerous and are smaller than on either side . In the densest regions these granulations may assume

r odlet s the aspect of very short blunt measuring up to mm . in diameter , and approximately the same in height . The median plate i s s et off from the lateral ones by a narrow of strip of cuticle , nearly destitute such elevations . The lateral plates are approximately right angled triangles in general out

rounding them .

R d u la i a . s The pharyngeal bulb large and strong, mm . in length by mm . in height , in form truncately conical , the radula sheath proj ecting very slightly behind and below . The radula is broad , short , and deeply grooved , colorless in front , but

- becoming straw colored posteriorly . The teeth are i n twenty six of rows , the rhachis the radula is naked , and the pleural teeth

- t o vary in number from forty six in the anterior half rows ,

ﬁfty in the posterior ones . The dental formula may be expressed

- 6 0 X 26 . 4 5 The teeth are all simple hooks in form , the ma r ow j ority except the outermost and innermost in each , being of 6 68 the same size and shape ( Pl . XII I , ﬁgs . 7 , ; Pl . XV, ﬁg . of The base a typical average tooth measures mm . , the height 76 OPISTHOBRANCHIATA OF BRAZIL

mm . The outermost tooth in each row is much smaller

than the average , the base being much shorter, often nearly rudi

mentary , and the hook much more slender , as is shown in the

6 PI . slightly oblique view in ﬁg . 9 of XIII . The next two teeth

adj acent to the outermost , are progressively larger and form a

transition to the remainder in the row . In like manner the inner 6 of . . most tooth each row ( Pl XV , ﬁg 7 ) is much smaller than its

dim en fellows , the succeeding ones increasing in size , the typical

sions being reached in the fifth or sixth tooth of each series . In front View all of the teeth of the radula are inclined toward f of the median line by a strong curve at their bases , the e fect which is partly nullified by a curve in the reverse direction in the f 6 o . . middle and upper portion the shaft ( Pl XIII , figs 7 ,

i er m l x Vs c al co p e . The esophagus begins with a large dila

tion immediately behind the pharyngeal bulb . It recurves upon

itself, narrows , passes through the commissural loop of the central

nervous system , and , after a short course , opens into the stomach .

The posterior visceral mass is bluntly conical , mm . long by

mm . in maximum diameter , its lateral and lower surfaces

on e . convex , the upper slightly ﬂattened The upper anterior mar

gin is deeply notched for the reception of the stomach , the pyloric

ﬂex u r e of which is uppermost , passing gradually backward into w h ich cou r ses of the wide intestine, along the dorsal surface the

- liver to the anus . At the left of the pylorus lies the sack like f f o o . gall cyst the liver , the greatest diameter which , mm , is of nearly equal to that the pylorus .

D REPRO UCTIVE SYSTEM .

Her m a h r odi ti c lan d an d d u ct p g . The hermaphroditic gland as of lies usual upon the upper and anterior portion the liver . The slight development of the reproductive cells rendered this

h r m a h r o gland relatively inconspicuous in the specimen . The e p ditic duct i s short and slender , passing forward from the right of of anterior lobe the hermaphroditic gland , and , after a course

1 . ca . 5 mm . , dilates into the long thick convoluted hermaphroditic

. . h . ampulla ( Pl XIV, ﬁgs 73 , 74 , This is closely coiled in a number of loops upon the posterior and lower border of the

- anterior genital complex , and makes up fully one third the bulk of the latter . Its approximate length is mm . , with a fairly

78 OPISTHOBRAN CHIATA OF BRAZI L

the organ . The gland cells are large and clear, with large, deeply staining nuclei , the reticular cytoplasm being distended f with a clear albuminous secretion , staining with di ﬁculty . The poor ﬁxation of the single specimen available precluded an y of satisfactory cytological study the gland .

n n i of Vas d efer e s an d p e s . From the distal end the prostate

v . d v as . . . gland passes the deferens ( Pl XIV, ﬁgs 73 , 74 , ) a slender tube , ca . mm . long, which courses with but few loopings outward and forward , terminating in the penis into which it rather suddenly dilates ( Pl . XIV, ﬁgs . 73 , 74 , It is lined with a of single layer slender columnar epithelium , surrounded by a thin layer of smooth muscle cells and a connective tissue adventitia . Toward the distal end the muscular elements become much i n

of r ae u tiu m creased , the wall the p p being made up almost entirely

of . them The penis was strongly retracted and curved upon itself , as was also the whole organ . It is bluntly cylindrical in shape , slightly tapering and is entirely destitute of any armature .

i n a Va a. . . v . g The vagina ( Pl XIV, ﬁgs 73, 74 , g ) is small its t and conical in general form , leng h in the Slightly contracted of condition being mm . , with a maximum diameter mm .

v a . d . Its slender duct ( Pl . XIV, ﬁg . 74 , g ) passes directly inward to the central region of the dorsal face of the anterior genital complex where it opens into the spermatotheca ( Pl . XIV, f . o t ﬁg 74 , In cross section about midway its leng h it

of . . has a diameter mm , of which mm is occupied by the lumen . The lining is formed by a single layer of cubical epithelium bearing long cilia , in the distal portion elevated into long ridges , which become lower and disappear in the proximal portion . The muscular coat is strongly developed , and consists of a circular and a longitudinal layer , enclosed externally by a connective tissue adventitia .

S er matoth eca an d s er m atoc s t p p y . The oblong ﬂattened Spermatotheca lies in the center of the dorsal face of the anterior f . . i s o genital complex ( Pl XIV, ﬁgs 73, 74 , It a light

- amber color, is slightly ﬂattened dorso ventrally, measuring

- — mm . in its antero posterior diameter by mm . dorso ventrally, of with an extreme length mm . It is lined by a high colum of nar epithelium , apparently ciliated , but the preservation the ca specimen renders this point uncertain . A connective tissue p D I SCODORI S VON I HERI N GI MAC FARLAND 79

of sule considerable thickness , intermingled with smooth muscle

ﬁbres , surrounds the organ . The vaginal and uterine ducts are 1 united in a common entrance into the spermatotheca . In ﬁg . 7 of PI is . XIII shown a reconstruction from sections with the relations of these ducts and of the adj acent organs . The vaginal

v a d . duct, g . , is shown in its proximal portion only, uniting with u d the uterine duct, . ., at thei r common entrance into the sper m at th a s th o ec . , p The uterine duct describes two S shaped loops of s e close together, receives the slender duct the spermatocyst , p . , and opens into the nidamental gland at its anterior end , and some distance from the anterior margin of the albumen gland . The of spermatocyst is an elongate pear shape , doubled upon itself, t its greatest diameter being mm . , and its leng h mm . It lies immediately in front of and external to the Spermatotheca

s e . ( Pl . XIV, ﬁgs . 73 and 74 , p )

N id am en tal - albu m en lan d com lex - g p . The nidamental albu men gland is rather small i n proportion to the remainder of the anterior genital complex . It is ovoid in outline , the broader end being directed forward and outward . The upper surface is nearly plane , the under surface slightly convex . The surface is marked

n ot as usual by parallel convolutions , which are however , very

on conspicuous , being quite faint the central dorsal region occupied by the albumen gland . The duct of the nidamental

- gland appears upon the ventro anterior surface ( Pl . XIV, fig . 73 , n i s - . large , and slightly flattened dorso ventrally . In cross 0 section ( Pl . XIII , fig . 7 ) its lumen is seen to be large , the dorsal of ventral and anterior walls being thin , and nearly equal thick ness . The posterior wall bears two strong parallel longitudinal d v . ridges , , and , proj ecting into the lumen and forming a deep of t o groove between them . At the distal end the duct these w ridges coalesce , the deep furrow becoming reduced to a shallow of groove upon the crest a single ridge . As the duct approaches

ou t the gland proper, this groove widens , the ventral ridge de creases and disappears , while the dorsal ridge merges into the of of roof the lumen the gland . Upon the external surface there is but little indication of the division into nidamental and albumen glands , such as is

D or ididae usually seen in other , but in sections the structural ff 1 di erence is clearly apparent . In Pl . XIII , ﬁg . 7 the boundary 80 OPISTHOBRANCHIATA OF BRAZIL

of the gland is approximately marked by the dotted oval line .

It occupies the median posterior portion of the complex . The

h . a. distal end of the hermaphroditic ampulla, , enters the con f off n ect iv e tissue stroma o the gland at its posterior end , giving

d . s . a the slender spermatic duct , p , lmost at right angles , and

2 . . . then dilates into a broad cavity , 5 mm in length and mm in diameter . Its wall is practically identical in structure with that i s of the hermaphroditic ampulla , and , like the latter organ , it

r m t oza packed full of sp e a . It is probably to be regarded as a fertilization chamber, Since it is here that the ova ﬁrst come in contact with the spermatozoa from a diff erent individual . Just beyond the middle third of the gland complex this cavity bends sharply at right angles , dilates somewhat , thence passes again in a course parallel with the long axis of the gland , narrowing rapidly

d . . of u . to the exit the uterine duct , , from the anterior end Just as the above mentioned dilation begins to narrow , a more slender off duct , mm . in diameter, is given at an acute angle , running of sharply backward and ventrally , and Opening into the cavity the albumen gland at its anterior end . This cavity is irregularly

- pear shaped in form , the broad end being turned forward and of outward , its tip extending nearly to the proximal end the lo . w gland complex It is lined by a cubical epithelium , with

on large spherical nuclei . Into it open all sides at intervals the of a secretory alveoli the lbumen gland , which may be either or as single , , is usually the case , branched into a small number of of divisions . The cells the secretory alveoli are columnar , ca .

mm . in average height, with large conspicuous nuclei , but their preservation did not permit making ou t any further details of D of their structure . orsal to the entrance of the branch the hermaphroditic duct into the cavity of the albumen gland , a somewhat broader duct passes forward into the cavity of the nidamental gland proper . This large cavity occupies the ventral portion of the nidamental gland throughout its whole extent, and receives the short blind glandular diverticula which form the mucous secretion . In general the cavity is undivided , save for a few irregular ramiﬁcations along its posterior and outer border into which secretory alveoli Open . The lumen of the duct is lined with small cubical cells with large nuclei ; in the posterior half of the gland these cubical cells are replaced by tall Slender columnar DI SCODORI S VON I HERI N G I MAC FARLAND 81

ones much similar to those of the terminal alveoli of the gland . f 2 f PI i n o o . An examination ﬁg . 7 XIV may aid a clearer per

n ceptio of the relations of the above described cavities . It of represents the principal ducts the gland complex in side View , as reconstructed from serial sections , the glandular alveoli and other subordinate ramiﬁcations being left ou t for the sake of of clearness . The dotted line represents the contour the gland of complex as seen from the front side . At the posterior end m h . a . the complex the large hermaphroditic ampulla p , enters ,

d h 1 h off s . . w c gives the slender spermatic duct , p , emerges from PI f . as . o the gland seen in ﬁg 74 XIV, the duct passing forward ,

oh . dilating into the fertilization chamber, f . , which makes a sharp , off knee like turn upward , then narrowing rapidly, gives the

x slender duct, , to the albumen gland , and receives the uterine u d x duct , . ., at the distal end of the gland complex . The duct , D or ids corresponding doubtless to the oviduct in other , passes of backward , and to the right , and opens into the cavity the l l a b . u albumen gland , . , triang lar in this side view , and terminating

- posteriorly in a blind blunt prolongation . At its antero dorsal end this cavity passes into the duct connecting it with the cavity l of a b d . the nidamental gland , . , and opening into the extreme f anterior end of the latter at the exit o the nidamental duct .

1 n id The ventrally placed large cavity , . ., into which the alveoli of the nidamental gland pour their mucous secretion , extends f backward to the posterior end o the gland complex . Its dorsal of surface is concave , the ventral convex in the anterior half the organ , posteriorly becoming ﬂatter , and ﬁnally the concavity is shifted to the ventral side , the dorsal face being arched . From

n d the anterior end of the cavity the broad nidamental duct , . ., arises and emerges from the gland complex . In the figure the Space between these ducts and cavities and the bounding dotted line is t o be thought of as filled with the closely packed glandular diverticula arising from the cavities of the nidamental and albu men glands respectively . The architecture of these two glands appears to be Simpler D 2 f PI o . in this species than in most other orididae . From fig . 7 XIV the path taken by the eggs in traversing the diff erent ducts t o from the hermaphroditic ampulla the nidamental duct , N o of th e can be readily followed . trace a second duct from 82 OPISTHOBRANCH IATA OF BRAZIL

of albumen gland to the duct the nidamental gland, such as that Pol er described by Pohl for yc a could be found . r The circulato y, respiratory , excretory and nervous systems of this species presented no marked diff erences from other Dis co d or idin e a . ff The above species , which is clearly di erent from any hitherto H Von I h er in e described, I dedicate to Professor ermann g, the abl D of irector the Museu Paulista , Sao Paulo, Brazil , and the f f pioneer in the study o the Opisthobranchiata o that country . o 1 Type N . 47, Invertebrate S eries , Leland Stanford Junior U niversity Zoological Museum . m D I A L L I N A E Subfa ily U U .

Body neither hard nor soft ; depressed or subdepressed ; notaeum usually minutely villous , Often silky ; tentacles digitiform ; branchial aperture rounded , crenulate , branchial leaves tripinnate ; of anterior margin foot bilabiate , the upper lip notched . Labial armature none . Rhachis of radula naked . Pleurae multidentate , usually hooked . Penis usually unarmed .

G en u s PEL TO D O RI S B e h 1879. , rg ,

! ” P ltod or is Peltod r i Mi h il e . O s tt e , Bergh Ueber die Gattung , au s S z u 2 ungen der Zoologischen tation Neapel , II , , —M l l 8 . 2 2 2 . a aco H 1 . u . 79, p Untersuchungen , S p eft 1 1 — dsee 880 . Su I , , p 4 . Neue Nacktschnecken der , ff 8 —M l l . . 1 8. a aco IV, Jour Mus Gode roy , XIV, 7 . 188 1 . 8 . Unters , XVI , II , 9, p . 5

Body subdepressed , the circumference oval , subrigid , minutely l granular above . Tentacles digitiform . Branchia aperture rounded , the branchiae of few leaves , usually tripinnate . of Labial armature none . Rhachis radula naked , pleurae multidentate , the teeth hooked .

Prostate gland large . Penis and vagina unarmed . The genus Peltod or i s was established by Bergh in 1879 for

f P t om cu lata o . a r a the reception the type species Bergh , from the P cr u cis Mediterranean , and for a second species , . ( Oersted) , t o D is cod or is from the Antilles . The genus is much similar , ff di ering in the less soft body, and especially in the unarmed ff fﬁ labial disc . Whether such a slight di erence is su cient to c n ot of establish a distin t genus or may be a matter doubt . In this genus are placed the following species 1 P eltod or is atr om acu lata . Bergh . f Bay o Naples . Bergh l . c . Peltod or i r u cis 2 s c . . ( Oersted ) x Antilles , St . Thomas , ( Ruse) . Sainte Croi , ( Oersted ) . 6 18 . Journ . de Conchyliologie, III , 3 , 3

P ltod or i m au r i tian . e a 3 s Bergh . I sl . . 2 81 . Mauritius Bergh , Mal Unters . XVI , , p . 5 P eltod or is an u lata 4 . g Eliot . 2 1 . 0 0 1 0 East Africa Eliot, Proc . . Soc . London, 9 3 . P lt d o is u r e . e o r a a 5 Eliot . E l a A . E . st frica liot c. 84 OPISTHOBRANCHIATA OF BRAZIL

to o i e en Pel d r s r u b s c s . 6 . Bergh i o b a . 1 . . S 0 Malay Archipelago Bergh , g Exp 9 5

To this list is to be added the following new species , taken 8 1 D 2 8 . by Mr . Greeley at Riacho oce , Alagoas , July , 99

Pelt od or i s r eel e i g y Sp . N ov .

- ﬁ 77 82. a e X V s . Pl t , g

on e of But specimen is in the collection , no notes save that

locality and date accompanying it . The animal was rolled up in n ot a loose coil , and was apparently much shrunken by the pre

serving ﬂuid .

EXTERNAL CHARACTERS .

olo an d or m of C r f . The color the alcoholic specimen is very

pale yellowish pink everywhere, there being no special markings .

The dorsum is villous , quite velvety to the touch and quite

u u similar to D ia l la in this respect . It is equally rounded in front and behind , the general body shape being oblong elliptical , with the

wide, rather ﬂeshy mantle edges proj ecting well beyond the foot .

n i i n B r a ch ae an d r h oph or es . The thirteen branchial plumes

are short, simply pinnate and arranged in a complete circle about

the anus , which occupies the summit of a low papilla , the minute

- pore like renal opening being situated as usual , a little to the

front and right . The branchiae were completely retracted within . of the branchial pocket , the thin margin which is prominent ,

‘ m i n r oll - ed . o inutely villous , and slightly The antero posteri r f o . diameter the opening is mm , the transverse slightly less . The margins of the sheath of the deeply retracted r h in oph or es

C r h i n o h or es are similarly villous . The lavus of the p is club on shaped and perfoliate , with sixteen leaves either side . The

- tentacles are short, conical and dorso ventrally ﬂattened . F oot . The foot is broad and muscular, contracted , the

anterior end rounded and bilabiate , the upper slightly notched . D im en i on s s . The approximate length of the partly rolled

. of up specimen is mm , with a maximum width mm .

INTERNAL ANATOMY .

I te u m t n en . g The dorsal integument is thin , strengthened

everywhere with minute spicules . Around the base of each papilla of the velvety surface of the dorsum is arranged a radial

86 OPISTHOBRANCHIATA OF BRAZIL

dental formula f or the whole radula may be expressed as

X :60 49. i r m le Vs ce al co x . p The salivary glands are short and broad ,

. t i r m mm in leng h , scarcely extending beyond the c cu esoph a of geal ring the central nervous system . The esophagus i s short

and wide, passing downward and backward into the large stomach , which lies in the usual V shaped groove in the upper anterior of border the liver . The stomach is broadly wedge shaped above , mm mm . in length , . wide and mm . in depth , pre

senting a somewhat triangular cross section . The esophagus

enters at its lower anterior border, the intestine arising from the

upper posterior end and passing backward to the anus , lying in a of groove in the upper surface the liver throughout its course .

The latter organ presents the form of a blunt cone , the anterior

end deeply notched for the reception of the stomach , and facetted of of by the pressure the anterior genital complex . The cavity the liver opens widely into that of the stomach on the ventral of median line , immediately behind the opening the esophagus .

N o bile cyst i s present .

REPRODUCTIVE SYSTEM .

i l n d n d d u ct of Her map h r od tic g a a . The surface the liver is covered everywhere save on the central portion of the gastric

- groove , the anterior face and the antero ventral surface by the I ts ramiﬁcations of the hermaphroditic gland . duct arises by the union of a number of delicate tubules from the lobules of

- the mid dorsal face, immediately behind the stomach . It courses of forward and downward , between the right surface the stomach f or of and the anterior lobe of the liver , a distance mm . and dilates into the white hermaphroditic ampulla on the lower

. 82 h . O f . surface the anterior genital mass ( Pl XV, ﬁg , of A n ter i or g en i tal compl ex . The organs this complex are very compact , convex upon the outer and inner surfaces , in lateral view oval , from above more pointed posteriorly than in f o . front . The extreme length the complex is mm , its width

mm . , and height mm . Its inner face bears a shallow broad groove , deepening toward the upper margin . Anterior to this groove and forming a large part of its anterior wall is f o . a smooth , light brown surface , the wall the spermatotheca ( Pl PELTODORI S GREELEYI MAC FARLAND 87

82 XV, ﬁg . , Below , wedged in between the spermatotheca in front and the albumen gland behind , appears the surface of the glistening white hermaphroditic ampulla . Encircling the spermatotheca and this ampulla is a lobulated mass , the prostate

. 82 gland ( Pl . XV , fig , Posterior to the hermaphroditic of ampulla and the spermatotheca , the inner face the anterior of genital mass is made up principally the albumen gland , finely convoluted and of a light yellow color , surrounded above , behind and below by the thicker convolutions of the pinkish nidamental of gland . The lower posterior border the complex is occupied by a broad convolution of the nidamental gland , which is of a reddish hue , markedly distinct from the remainder of the mass . 82 In the figure of Plate XV , the nidamental and albumen glands

n ot have been dissected away, and are shown .

H r i i u ll a er maph od t c amp a. The herm phroditic duct dilates of of into its glistening white ampulla , midway the inner face

i s the anterior genital complex . This ampulla somewhat lunate in form , curving downward in a groove between the spermato theca and the albumen gland , thence outward and upward upon the external face of the complex to a point immediately below

and in front of the spermatocyst , where it narrows suddenly,

off . 82 s gives the spermatic duct ( Pl . XV, ﬁg , p . and passes inward and upward into the nidamental gland .

Pr os tat lan d an d n is e g p e . The very short spermatic duct passes at once into the large lobulate prostate gland ( Pl . XV,

82 e of su r ﬁg . , ov rlying and forming the whole the front f off face o the complex . From its superior surface is given the

f n en 82 v . v as de e s . . relatively long ( Pl XV, ﬁg , which of describes an irregular loop , free from the surface the anterior

- genital mass , above its antero median transverse groove , and

r e tiu m passes downward and outward into the p a p u . The prae

u tiu m p is mm . long by mm . in maximum width , tapering inward to the v as deferens . Within it is inclosed the retracted

- c lin d r o t . glans penis , y conical in form , its leng h mm , its greatest diameter mm . , tapering gradually to a truncate

of . tip with a terminal diameter mm , smooth and enti rely unarmed . 88 OPISTHOBRANCHIATA OF BRAZIL

in n u t r ae u tiu m Vag a a d d c . Parallel to the p p and a little

behind it pass the more slender vagina and vaginal duct . Their combined length is much less than that of the v as deferens and

i . . 82 v a . r ae u t u m . the p p The vaginal duct ( Pl XV, ﬁg , g

passes inward between the prostate gland in front, and the sper

m atoth eca of . . , opening into the latter after a course ca mm 2 h 8 s t . The spermatotheca ( Pl . XV, ﬁg . , p ) is ellipsoidal in form , 2 en mm . in length by . 5 mm . in width , and is covered almost

t i r el y by the prostate gland and the adj acent organs , being exposed only for a small portion of its extent upon the inner face of the

82 u . anterior genital complex . The uterine duct ( Pl . XV, ﬁg . , d ff . o of i ) i s given very close to the entrance the vag nal duct ,

passes directly outward , becoming visible upon the outer surface of the mass , curves backward beneath the spermatocyst, and

of . opens into the cavity the nidamental gland It receives , not its of far from origin , the short duct the pear shaped spermato

cyst , which lies upon the upper outer border of the median f o . t portion the complex In leng h it measures mm . , in

width mm . of of Owing to the loss this portion the material , which of of 18 was being dissected at the time the earthquake April , 1 0 6 to as 9 , I am unable give any further details to the structure of the prostate, nidamental and albumen glands . The anatomy of the other organs of this species do not depart markedly from the other members of the genus . of D r This species is named in memory . Arthur W . Greeley, of the zoologist the expedition , whose untimely death cut short of a life full promise in his profession . 1 8 . S Type No 4 , Invertebrate eries , Leland Stanford Junior

University Zoological Museum .

90 OPISTHOBRANCHIATA OF BRAZIL

Rh in o h r Body somewhat elongate, not depressed . p o es per f . o l n r foliate Anterior angles foot not prominent . Cerata cy i d o conical , arranged in groups , each of which is borne upon a

- of u slight , crescentic, dorso lateral elevation the integ ment .

of Masticatory margin mandibles long, minutely denticulate, or smooth .

Radula uniserial , the teeth pectinate , emarginate in the center .

This genus was proposed by Bergh in 1864 for the reception ’ h i o oli t n 18 1 of D elle C aje s E lis n eop a a as the type species . In 7

S s ar as si cola he transferred to this genus a second species , p . g K r o er 1882 188 ( y ) , and in and 5 , in the papers cited above , made further additions to the k nowledge of the anatomy of the type

Tr i n ch ese species , which had been already extensively studied by in 1878. Vayssiere added to this in his excellent researches of 1 0 upon the Opisthobranchs the Gulf of Marseilles , in 9 3 t S i n or n a a . . recognizing a third distinct species , p . ( A Costa ) Sib o a The g collections contained a fourth species , which was described by Bergh in 190 5 in his beautiful work upon the

Opisthobranchiata of that expedition .

At the present time the list of species described as belonging to this genus i s the following

I u r illa n eo olitan a D h ia . S p p elle C je) . a Mediterranean , C pe Verd Islands .

2 S u r illa s ar as s icola Kr o er . p g ( y ) .

S . argasso Sea , Atlantic Ocean

S u r illo i n or n ata 3 . p ( A . Costa ) .

Mediterranean .

S u r illa or i en talis 4 . p Bergh .

Kei Island , Malay Archipelago .

of All three these species are closely related , the ﬁrst two being held by Bergh to be questionably distinct . The following description deals with the ﬁrst member of this genus thus far of taken from the West Atlantic . After a careful comp arison its

of S n ea oli tana structure with that p . p , and with the description of the others , I am Of the opinion that it represents a distinct species , though certainty in this regard can only be secured by the of study of a series specimens . SPURI LLA BRAZILIANA MA C FARLAND 91

ill b az l n S N v S u r a a a . p r i i p o .

- 3 6. at es X VI VI I V I an d s . 8 9 Pl , X , X II X IX ; Fi g

o But one specimen was taken by the expedition , the l cality ! D 2 8 label reading Riacho oce , Alagoas , July , The preser vation of the specimen was rather poor , it having been killed

r h in o h or es in a distorted position , with the head , tentacles and p of r e strongly contracted , and the posterior portion the body ff r . o cu ved dorsally The cerata had nearly all fallen , but were i s preserved in the bottle . The original color had entirely d ap ear ed p , nor were any notes taken as to the color, dimensions or r appearance in life . The animal in the prese ved condition had

a uniform , pale pinkish coloration .

EXTERNAL CHARACTERS .

im n i n s D e s o . . The total body length is circa mm , of i of . d s which the length the foot makes up mm , the quite or t t ed head region the remainder . B od or m y f . The general body form i s slender and somewhat r compressed , tapering posteriorly to a sho t bluntly pointed tail , the general body form being similar to that of the other species

ﬂex ed of . r e the genus The mouth is everted and , the whole head region being strongly contracted . The oral tentacles in their contracted state are tapering, with blunt extremities , thei r

0 . . t basal diameter being 5 mm , and approximate leng h mm . R hi n o h or es r h in o h or es p . The strongly contracted p are per u foliate , the clav s bearing eight prominent leaves , which alternate on the posterior side with an equal number of lower ones that t ex end forward , half way around the clavus from the posterior

median line . t Cer a a. The cerata are lanceolate, ﬂattened , and variously r of cu ved , in part due to the action the preservative , but also often showing the S shaped cu r ves common in Sp u r illo n eap oli

tan a r . The smaller cerata are more rounded and conical in fo m .

The cerata are arranged in eight groups along the dorso - lateral i f fi s 0 of o . . marg ns the body ( Pl XVII , g 9 , Each the first five of of r t these groups is made up two slightly cu ved rows of cera a , the upper ends of the rows approaching each other and uniting ar e to form an like figure , borne upon a slight integumentary of elevation . The anterior limb each of these arcs contains more 92 OPISTHOBRANCHIATA OF BM ZI L

on e cerata than the posterior , the number in both decreasing in each group from the ﬁrst backward , until the posterior limb entirely disappears , the anterior row being alone represented in 0 1 the groups from the sixth onward . In ﬁgs . 9 and 9 the of bases the cerata are outlined by small circles , indicating the of relative size and positions these groups . The number does not exactly correspond upon the two sides of the body for each ff i s group , but the di erence not marked , the total number for the

- dis r i . t right side being eighty , that for the left eighty one The b u t ion of the cerata in the anterior and posterior limbs of the groups i s shown in the following tabulation .

R I G HT SI DE LEFT SI DE

These ﬁgures may be expected to vary somewhat in individ ff n als of di erent sizes , as they do also for the Mediterranean species . The anterior limb of the ﬁrst group begins in front of and

h r below the bases of the r h in op o es . The reproductive openings of are situated close together , below the ﬁrst arc cerata on the right side ; the anal opening is placed on a prominent tubular papilla , well up on the same side , and is included in the span of the second group . The opening is large , with slightly lobulated margins ( Pl . XVI , ﬁg . The very minute renal opening is immediately in front of its base .

94 OPI STHOBRA N CHIATA OF BRAZIL

According to the descriptions and ﬁgures of Tr i n ch ese r i h t the single crest is found upon the fulcrum of the g mandible, l e t on e S u r illa n eo oli tan a the double crest upon the f in p p , which of i s the reverse the condition here described . In the preparations of S n ea oli tan a which I have made Of the mandibles p. p the rela tions of the single and double crests is the same as that which I S br a ilian a . con have found in p z . I am at a loss to explain the

t r adi ction in results .

R ad u la of of . The radula is uniserial , consisting a series eighteen strongly arched slightly emarginate pectinate plates of an amber color . These plates increase rapidly and regu larly k in size from before bac ward , and present a slightly convex ante

rior face . The ﬁrst ﬁve plates have their central denticles worn

and broken , the last ﬁve are still inclosed in the radula sheath of where they are developed . The dimensions the individual

teeth range from a basal width of mm . , and a height, meas u r ed from the middle of the base line to the top of the mi ddle of of denticle , mm . , in the ﬁrst plate , to a width mm . ,

and a height of mm . in the eighteenth plate . The relative PI 8 8 proportions are well shown in . XVI , ﬁgs . 3 and 4 , which f illustrate the twelfth and the ﬁrst plates o the radula respectively .

Each plate is slightly emarginate at its summit ( Pl . XVI , ﬁg . but none so much so as to give the bilobed appearance ’ ﬁgured by Bergh 7 1 Tr in ch ese and Vayssiere ’ 0 of 3 ) for the other species this genus . The denticles are slender

and lanceolate , the lateral ones slightly curved , the remainder

straight, increasing in length from the sides upward , and reaching

a maximum height about the eighth or tenth from the center . The

central denticle is low and broad , usually with a small denticle

next to it on either side , the succeeding ones increasing

in length rapidly . The number of denticles in the ﬁrst plate is in the ﬁfth in the twelfth in the

: 6 : ﬁfteenth 3 ; and in the eighteenth 4 7, the increase in

number thus being irregular . In a radula taken from an indi

of S n ea oli tana of i n vidual p . p the same body dimensions this

i n of r e r e crease the number denticles is much more regular , p

s entativ e : 1 plates running as follows . First plate 5 ; ﬁfth plate 2 3 : 1 2 3 tenth plate 34 twelfth plate 32 : 1 35 ﬁfteenth

plate 35 : 1 37 ; eighteenth plate : 44 ; and in the twenty - sixth SPURI LLA BRAZILIANA MAC FARLAND 95

1 of and last plate : 5 . In this radula the basal diameter the plates varied from mm . in the ﬁrst , to mm . in the

- litan a S . n ea o twenty sixth . In p p the three central denticles are very small or rudimentary, while in the Brazil species the central i s . denticle valid and much larger ( Pl XVI , ﬁg .

li ar l n d S a v y g a s . The extremely long salivary glands are PI ﬁ s 86 8 of . . shown in g . and 7 XVI They have the same general appearance and relations as exhibited in the other species of

u illa Sp r .

ou te of Cen tr al n er v s sys m . The ganglia the central nervous system are inclosed in a strong closely applied connective tissue capsule , from which in the Specimen at hand the ganglia had in part shrunken away, the general preservation precluding any of satisfactory detailed study the cells and ﬁbre tracts in sections ,

ou t For though the general relations could be readily made .

of n ea oli tana comparison several Specimens Sp . p were also dis s t ed ff ec . In general there is no great di erence between the two species , but some marked discrepancies were noted between the Neapolitan species and the ﬁgures given for it by Bergh and by Tr i n ch es e especially in respect to the origins of ’ the nerves . In Bergh s ﬁg . 4 , Pl . XII , the nerves appear to be

represented in a diagrammatic fashion , they being neither num

n or bered , mentioned in the text , the author manifestly laying of most stress upon the form and grouping the ganglia . In the ! ’ of Tr in ch ese earlier paper , Nuovo Ricerche sull Organizzazione ” ’ Eolididei d ell A ccadem ia del Cervello degli , Memorie delle

’

dell I n stitu t O 18 S . Scienze di Bologna , 75 , erie III , T V , he devotes h is attention to certain peculiarities of the nerve cells as seen in

preparations , cleared in glycerine and ﬂattened under a cover

h i s glass , ﬁgure of Tavola I giving but a faint idea of the actual f form of the ganglia and the origins o their nerves . In his ” ! S u r illa' n ea oli tan a Anatomia e Fisiologia della p p , cited above ,

this is corrected in the ﬁgures of Tavola X I , which present the best representations of the central ne r vous system of this Bolid

ili n u of S . br a a a yet published . In the ﬁg re the same for p z , given 6 I . on P . XIX , ﬁg 9 , I have adopted the designations used by of Tr in ch ese for the nerves for the sake of ease comparison , though I must disagree with him as to the actual origin and 96 OPISTHOBRANCHIATA OF BRAZIL relations of some of these ne r ves in both the Brazilian and the

Neapolitan forms . In studying both species the central nervous system was carefully freed from its attachments , stained in Paracarmine , and m icr osc0 ic cleared in glycerine . To facilitate p examination , and to

r of avoid unnecessa y displacement the parts concerned , a piece of glass rod was drawn ou t in a ﬂame to the approximate diameter r of of the esophagu s of the animal . A sho t bit this was passed through the circumesophageal loop of the central nervous system , and the whole mounted on a slide having a suitable depression ground in it . The preparation may then be rotated and examined from all sides , without danger of disturbing the relations of its parts . The use of the Zeiss binocular di ssecting microscope enormously facilitates the recognition of the relations of the ganglia and their nerves . The dorsal portion of the nerve collar is made up of the

- c l . . 6 . fused cerebro pleural ganglia ( Pl . XIX , ﬁg 9 , p in con tact along the median line , the cerebral portions being j oined by the very short and broad cerebral commissure . The two ganglia off are marked from each other by a slight transverse constriction , dividing the complex into two approximately equal portions ,

on e the anterior, cerebral being slightly larger than the posterior , pleural part . While in the main the nerve cells correspond in their distribution to these divisions , there is no middle region of between the two entirely free from them . The lengt h the of whole complex is mm . , the transverse diameter each cere m bral portion . , that of the pleural portion mm . Lateral to the esophagus are situated the ellipsoidal pedal

d - 6 e . . ganglia ( Pl . XIX , ﬁg . 9 , p g ) connected to the cerebro pleural complex by the very short cerebro - pedal and pleuro - pedal con

n e tiv es t . c . The maximum leng h of the pedal ganglia is mm , — with an antero posterior diameter of mm . , and a dorso ventral diameter of mm . The ventral portion of the circumesophageal ring is made of up of the commissures . These are three in number , two which are united together in a common sheath , forming a broad band . In this band are included the broad pedal and the narrower su b d 6 e . cerebral commissures ( Pl . XIX ﬁg . 9 , p Separate

sh h tl from this , but close to it is the g y longer pleural commissure

98 OPISTHOBRA NCHIATA OF BRA ZIL

of . is worthy separate notice, however I am unable to confirm ’ He Tr in ch ese s figures as to its origin in either species . shows it as arising from the lower outer margin of the pedal ganglion as a pedal nerve . According to my preparations and sections it — is a nerve from the cerebro pleural complex , its fibres penetrating the capsule of the pedal ganglion at the upper inner border of the latter , immediately above the connectives j oining the pedal gan

- glion to the cerebro pleural complex . The ﬁbres do not enter the pedal ganglion , however, but course directly into the pleural

of - portion the cerebro pleural group . A similar relation may

i n or n ata f also be suspected in Sp . in the case o the nerve num ’ ! i r 6 6 f PI . a ss e e s . o V bered , in ﬁg 3 III , in y Recherches sur les ” i b r an h e d u O sto c s . Mollusques p Golfe de Marseille , Supplément A decided asymmetry is to be noticed in the nerves of the pedal ganglia upon the two sides . Whether this has any special signiﬁcance or not could not be determined by the dissection of

n but o e specimen alone . Counting the olfactory stalk as a nerve we have seven

off - of nerves given from the cerebro pleural complex , ﬁve which on e arise from the cerebral portion , from the intermediate zone

on e between the cerebral and the pleural regions , and from the pleural alone . As the Optic and otic ganglia are sessile , they are not included in the above enumeration . From the pedal ganglion h two large nerves arise , w ich are distributed to the sole of the of foot . The peripheral distribution the nerves was not worked ou t in detail , such an undertaking requiring much more material than was available .

REPRODUCTIVE SYSTEM .

The hermaphroditic gland is made up of eight spherical or b lobules , closely packed together and more less ﬂattened y of or mutual pressure . S ix these are paired , alternating more less in position , while the seventh and eighth are unpaired . The r e glans penis is short and conical and entirely unarmed . The maining organs of the reproductive system are not greatly ff of of S u r illa of di erent from those the other species p , all which seem to show close similarity . The general diff erences shown by this Specimen in amatomi b l cal organization , especially as shown y the mandibles and radu a, SPURI LLA BRAZILIANA MA C FARLAND 99 seem sufﬁcient to authorize its recognition as a member of a species distinct from the European ones already described . The

u r ill r i i n f r name Sp a b az l a a is here proposed o it .

. 1 S Type No 49, Invertebrate eries , Leland Stanford Junior

University Zoological Museum . L ITERATURE .

ADAMS, ARTHUR . id l of a Sol u a. 1854 . Monographs Act eon and Proceedings

- 62 1 o 18 8 . 20 0 . c . S London , 54 , p 5

BERGH , RUDOLPH .

6 A n atom isk e Bid r a Ku n d sk ab ZEolidier n e. K . 18 4 . g til om k id 0 k k r Raek e N atu r v . i n k els . . de s . S S B anske V , 5te , g

- I - A fh 1 1 . . Math . . VII , p . 37 3 4 , Tab IX

18 1 Beit r ae e Ken n t n i ss Sar as 7 . g zur der Mollusken des g

- b . m r . . . . . s o ee es . Ver d k k Zool Bot Gesellschaft in Wien ,

- - 12 1 0 8 . . XXI , p . 73 3 , Taf X I XIII ’ 18 a K Eh r en b er sch en D 77 . ritische Untersuchungen der g ori

h r Malak oz o lo is h en a b . D o c den . J . d eutschen g Gesell

- 6 schaft, IV, p . 4 5 7 . it r K n n n i ZE lidi d n b b Be ae e e t ss o a e . . 18 . 77 g zur der , IV Ver

- - 6 . d . k . k . Zool . Bot . Ges . in Wien , XXVI , p . 737 7 4 , Taf

- IX XII .

M l olo i h e 18 c . a ac sc S 77 g Untersuchungen , XII , in emper , im Reisen Archipel der Philippinen , II Theil , Wissen

h ftli ch - 6 s c a e . . Untersuchungen , Band II , p 495 54 , Taf

- LVII LXI .

18 8a u ds . S ee . 7 Neue Nacktschnecken der , IV Journal Mu

ff H 1 - I - . . 0 V. seum Gode roy , XIV, p 5 , Taf . 1 b M la olo is h 8 8 . a c c e . . c . . 7 g Untersuchungen , XIII l , p 547

60 1 - , Taf . LXII LXV . 18 a Beit r ae K i l . e en n tn ss ZEo idiad en er h 79 g zur der , VI . V .

- - . . . . . 18 8 . 8 d k k Zool Bot Ges . in Wien , 7 , p 553 5 4 , Taf .

- VI VIII . 8 b Di r i 1 . e Do o sen ah r b 79 p des Atlantischen Meeres . J . d .

D M lak oz ool — a . . 2 6 eutschen Ges VI , p . 4 4 . 18 P l c. e todor i Mit h l 79 Ueber die Gattung s . t ei u n gen aus S z u 2 22 der Zoologischen tation Neapel , II , p . . 1 Mala lo i h 880 . co sc e Su lem en th ef g Untersuchungen, pp t I ,

1 - A - . c . . 8 . F l , p 7 , Taf . 1881 Mala olo . c i sch e Su lem enth eft g Untersuchungen , pp II ,

- - 1 c . 12 8 . . L . . G , p 79 , Taf

10 2 OPISTHOBRANCHIATA OF BRAZIL

H D . . ALL, W

1 . on . 889 Report the Mollusca, Part II Gastropoda and 2 h od . 0 1 H Sca a. 0 . p Bulletin Museum Comp arvard ,

- I - 1 2 . . XVIII , p . 49 , Pl XL

1891 . Mollusks from the Vicinity of Pernambuco . Pro

ceedin s of of S g the Washington Academy ciences , III , P

H . . D . . S ALL, W AND IMPSON, C T

l f . S . 1 0 1 o . 9 . The Mo lusca Porto Rico Bulletin U Fish

- - 1 2 . 8. Commission , XX , Part I , p . 35 5 4 , Pl 53 5

D . . OBSON, G E l a on dact lom e a. 1880 . Notes Aplysia y Journal Linn ean

- 1 160 . Society , London , XV, p . 59

ELIOT, C . 1 on 899. Notes Tectibranchs and Naked Mollusks from

18 8 . . S Samoa . Proc . Philadelphia Acad ciences , 9 , p — 12 2 . . 5 5 3 , Pl XIX

GOULD, A . A .

18 2 . S . . 5 Mollusca and hells U S . Exploring Expedition ,

XII . Philadelphia . H VON E . I ERING,

18 e 77 . Vergleichend Anatomie des Nervensystems und

- 1 2 0 . Phylogenie der Mollusken . Leipzig , p . 9 , Taf

I - VIII .

18 6 Ken n tn iss N u dib r an ch i en Br z ili an i s h n 8 . Zur der der a c e

Kii st h r b . . D M l k z l e. a a a o oo o G es ellsch . J d eutschen g . ,

- . 2 2 2 0 p 3 4 , Pl . IX .

18 . ao S S . 97 A Ilha de ebastiao Revista Museu Paulista ,

- . 12 1 0 . II , p 9 7

- D UTHI ERS H DE LACAZE , . 188 . S G aster o od s A l 7 ysteme Nerveux des p e ( type p ysie ) .

. . 8 Comptes Rendus Acad Sci Paris , CV, p . 97 . E LINN , C .

1 8. S l th d H l a o c . o m i 75 ystema Natur e, , ae.

1 66- 6 8. S h a 12 t . 7 ystema Natur e, ed

1 88- 1 . S a 1 7 795 , . . . ystema Natur e 3th ed Cura J F Gmelin , Li s iae 1 0 Vol p ( 79 , . I , Pars VI ) . LITERATURE 10 3

MA ZZA RELLI , GIUS . ’ ’ 1 889. Intorno all Anatomia dell Apparato riproduttore A li ie Z l s oo o . nelle p del Golfo di Napoli . g Anzeiger,

- 0 6. XII , p . 33 33 1 0 a Su l ﬁ siolo ico am mer 89 . Valore g della Vescicola di Sw

A l i Z o - s ae o lo . 1 dam delle p y . g Anzeiger, XIII , p . 39 399. 18 0 b 9 . Ricerche sulla Morfologia della Glandola del Boh adsch a . . ﬁ s . nelle Aplysiid e Mem . R Accad . Sci . e

. 1 mat Napoli , IV, App . . ’ 1 1 89 . Ricerche sulla Morfologia e Fisiologia dell Apparato A l siae riproduttore nelle p y del Golfo di Napoli . Mem . i ﬁ s . Sc . . . 2 . R . Accad e mat Napoli , IV,

18 Mon o r aﬁ a ae 93 . g delle Aplysiid del Golfo di Napoli .

Soc . . . . a N o . Mem . Ital Sci ( dei XL) , IX , Ser 3 , . 4 , p

1 - 222 I - , Tav . XIII .

MORCH, O . A . L .

5 m alacolo i u e d es 1863 . Contributions la Faune g q Antilles

2 1- danoises . Journal de Conchyliologie , p . 43 . ’ D ORBIGNY, A . ’ - l A m r i 1 18 . é u e . 835 43 Voyage dans q Méridionale Paris , 18 6 Vol . V, 3 . PELSEN EER , PAUL .

188 le Ptér o od es . 7 . Recherches sur systeme nerveux des p

- 12 Archives de Biologie , VI I , p . 93 9, Pl . IV .

r i s h ob r an h es . . 1 R su O t c . 904 . echerches divers p Mem Cour

1 - I - Acad . Roy . de Belgique , LII , p . 57, Pl . XXV . ’ 6 Lan k ester s on 1 0 . . 9 Mollusca Part IV, A Treatise

Zoology . London . P LSBRY H I . . , A

8 S of . 1 95 . On the tatus the Names Aplysia and Tethys

- 18 0 . . . S Proc Acad Nat . ciences , Philadelphia , 95 , p 347 35 ’

8 f . 1 6 . o 9 Tryon s Manual Conchology, Philadelphia , Vol

XVI . H POHL, ERMANN . 1 90 5 . Ueber den feineren Bau des Genitalsystems von Poly l h r h r d r i in ea a b ii e . A b u a ta. c cera q Zoologische J , Anat

2 - 2 2 - 2 6 teilung, Band XXI , p . 4 7 4 5 , Pl . 5 .

RANG, S . 182 s 8 H A l ien s . . istoire Naturelle des p y . Paris I 04 OPISTHOBRA NCH IATA OF BRAZIL

R . OBERT, E ’ A r es A l si s C a eil d e . 1889. Sur l pp reproducteur p y omptes R 16 endus Acad . S ci . Paris, CIX , p . 9 . E S MITH , . A .

18 2 R on of ae. 7 . emarks S everal Species Bullid Annals and

H - Magazine Nat . istory, IX , p . 344 355 . TRI N CHESE , S . R ’ r 1875 . Nuovo icerche sull O ganizzazione del Cervello ’ Eolidid i l e . . o degli . Memorie dell Accad Sci de le Istitut

- I - 1 8 . . di Bologna , Ser . III , T . V, p . , Tav III 8 8 u ill a olit 1 S r a n e an a . 7 . Anatomia e Fisiologia della p p ’ l Memorie dell Accad . Sci . Istituto di Bo ogna, Ser . I II ,

T 0 - 0 T I - . IX, p . 4 5 45 , . XII . E VAYSSI RE, A . 188 t su r les Mol 5 . Recherches zoologiques e anatomiques lu s u es O i stob r an ch es du q p Golfe de Marseille, I Tecti ’ du H branches . Annales Musée d istoire Naturelle de

i - - 1 181 . 1 6 Marseille , Zoolog e, Mémoire 3, p . , Pl . 1 r n h l 888. N u dib a c e e s o s t A c osses . c . Ibid , II , g l . , III ,

1 1- Mémoire 4 , p . Pl . 7 .

1 l men - 0 . u t S e . 1 c . 10 . 8 9 3 Ibid , pp , VIII , Mémoire 3 , p . 73 ,

Pl - . II III .

18 8. d es Pleu r ob r an chidés 9 Monographie de la Famille , I , d es e i Annales S ci nces Naturelles , Zoolog e, VIII ,

2 0 - 0 2 1 - 2 8 p . 9 4 , Pl . 3 .

1 0 1 1 - - . . . c . 1 8 I 9 Ibid , II , XII , p . 5, Pl . VI . ! B ATSON, R . . 1886 Report on the S caphopoda and Gasteropoda collected H by . M . S . Challenger . Zoology Challenger Expedi

- - - - . i v 1 6 PI I L I tion, XV, p , 75 , . , III . ZU CCA RD I , R . ’ ’ 18 90 . Intorno all Anatomia dell A pparato digerente nelle A l siae o p y del Golfo di Napoli . Boll . S c. Nat . Napoli ,

- 1 T 1- 2 IV, p . 5 4 , . .

PLATE I .

Teth s d act lom ela y y ( Rang) .

1 of th Fig . . Median and ﬁrst lateral teeth of each side 49 and oth 62 5 rows of radula . x . 8th th l oth of th o h of . 2 . t Fig , 9 and lateral teeth 49 and s rows 62 radula . X .

h h r 18t 1 2 t of oth ow . , 9th and 9 lateral teeth 5 of radula 2 X 6 .

2 n d th of th Outermost teeth , the 3 to 37 laterals s4 62 row . x . 1 10 A single typical lateral tooth . x . Side view of the outer face of 5th laterals of the 49th

oth . 62 and 5 rows x .

. w . a Fig 7 Labial armature in surface Vie , anterior ; p , poste x 1 rior margin . 95 .

PLATE II .

f Teth s d act lom l 8 o e a . Fig. . Central nervous system y y ( Rang) d cer . . e . . l . g , cerebral ganglia ; p g , pedal ganglia ; p . g ,

bu c . . c con pleural ganglia ; g , buccal ganglia ; . p . ., cere

- l n - b r o c . . co . on pedal connectives ; p , cerebro pleural c

i - b . con . n ect v es c . l ar ; , cerebro buccal connectives ; p p .

- con . l v con , right pleuro parietal connective ; p . . ., left

- com . pleuro visceral connective ; p . , pedal commissure ; d l com . ar a e a . p . p . , p p commissure The nerves from each ganglion are numbered s er

i all y as described in the text , and are distinguished by l b . c . . or . the preﬁxed letter, , , p , p , indicating their repec

n or e . tive ga glia , buccal , cerebral, pleural p dal x

PLATE III .

- 1 Teth s dact lom ela Figs . 9 4 , y y ( Rang) .

9. Buccal ganglia in situ , seen obliquely from below and l f s . es . o . the right side . , cut end esophagus ; g , right

salivary gland , its severed distal end bent forward and

u c b . con . b c . . . to the right ; g , buccal ganglia ; , cerebro

buccal connective . The buccal nerves are numbered 1 6 th 6th serially from to . In this specimen the s and 8 nerves arose from a common trunk . x .

- 10 . . Buccal ganglia , ventro posterior face Lettering as in 8 Fig . 9. X .

- 1 1 . . Buccal ganglia , dorso anterior face Lettering as in 8 Fig . 9. x . 12 Posterior margin of labial a r mature showing outlines

f f r dlet s 2 2 o bases o the o . x 3 . of 13 . Two elements the labial armature from anterior i of 1 marg n plate . x 37 .

- 1 . r . . 4 . Parieto visceral ganglion complex p . g , right parie l v l / . ar tal ganglion ; . . g ,left visceral ganglion ; p . p .

c - l n on o . v . co ., right pleur parietal connective ; p . , left

- r . I . I st or pleuro visceral connective ; . p , parietal , vulvar r I a ne ve ; . , its branch forming an anastomosis with the branch of the 3 r d pedal nerve supplying the Organ of Boh adsch 2 or S h r adi o— r . . O ; p , second parietal , p ctenidial l I of m m er n . v . Sw a erve ; , ﬁrst visceral nerve to vesicle

l . v . 2 dam , the Spermatocyst ; , second visceral nerve ; l v f l . v . a. . . b . t w o o 3 , and 3 , the main branches the dis third visceral nerve , in some specimens arising as r tinct nerves , in othe s branching from a common trunk .

1 - 2 2 T B ll eth s cer v i n a a . Figs . 5 , y and Simpson

f 8 Outline o labial armature . X .

x 18 . Rodlet from anterior portion of labial armature . 3

of n of Boh adsch or Surface View Orga , hypobranchial

- . a. I l gland , artery ; , nerve from right peda ganglion ; 2 x 6 , nerve from left visceral ganglion . .

PLATE IV

cer v in a Dall and Simpson

Median and ﬁrst three lateral teeth of twentieth and

- ﬁ r 62 twenty st rows of radula . x . f Fourth to tenth lateral teeth of same rows o radula . 62 x .

Eleventh to twenty- second ( outermost) lateral teeth of same rows . The three ﬁgures of this plate represent the whole extent of two rows of teeth from the middle of 62 to the side the radula . X .

PLATE V

i Tethys cer v n a B all and Simpson .

on 2 th Median and ﬁrst lateral teeth either side , 4 and 2 th of 5 rows radula . x 94 . l 2 th 2 th Sixth, seventh and eighth latera teeth , 4 and 5 of rows radula . X 94 . Seven outer lateral teeth of 29th and 3oth rows of radula . x 94 .

D of of 2 h r etail sixth lateral tooth 0 t ow of radula . 180 x . D of 1 of oth etail 4th lateral tooth 3 row, from opposite f 180 . side o radula . x

PLATE VI .

Tethys cer v in a Dall and Simpson

Alimentary canal from below . The convolutions of the intestine are shown in their natural position , the liver

e. having been dissected away . , lower end of the l r m s t i n . o . . esophagus ; g , ingluvies , ﬁrst stomach ; , ' t or s . muscular band of second , grinding stomach ; 3 , i t . . h coe. n third stomach ; . , hepatic coecum ; , intestine

X 3 . of Relations hepatic coecum and bile chamber . The wall of the lower portion of the third stomach and the

ﬁrst portion of the intestine have been cut away, show ing the entrance of the large ducts of the liver in the opposite wall . The substance of the liver itself, which here almost entirely incloses the alimentary canal , has

h . coe l . r . been dissected away . ., hepatic coecum , the prolongation into the intestine as a longitudinal ridge of on o f e f the folds in the wall o the hepatic coecum . x 5 . s Reproductive sy tem seen from below , the right border v t s m h d o . . . . . being above and to the left . , ovotestis ; ,

s c . d c small hermaphroditic duct ; p . , spermatocyst ; . f f o s . . o duct Cuvier ; p p , spiral portion genital duct ; r f c . d o . o ov . s ov p , convoluted po tion genital duct ; p . . ,

co d s t h . spermatic duct ; p . ., copulatory duct ; p , sperma h t t ot eca d . s h f h . i . o ; p , its duct ; , ﬂap the integument , upon the external face of which lies the vulvar aperture ;

. . l v . g g , genital ganglion ; . third nerve from left

8. visceral ganglion . x

PLATE VII .

Central Nervous System of Tethys cer v in a D all and

S . cer . . impson , in dorsal View g , cerebral ganglia ;

l c . c on . ed . . . p . g . , pedal ganglia ; p g , pleural ganglia ; p ,

- c l - con . cerebro pedal connective ; . p . , cerebro pleural

- l ar con . connective ; p . p . , right pleuro parietal con

i l on - n ect v e v c . . ; p . . , left pleuro visceral connective ; p

- m s c c . co . . . , pedal commissure ; , sub cerebral commis

m . ar eda co a l . sure ; p . p . , p p commissure The nerves are numbered serially in the order of their origin from of each ganglion . Those the pleural ganglia are des i n t ed l I l 2 f a . . o g p , and p ; those the cerebral ganglion c by the preﬁx to their respective numbers , while the nerves of the pedal ganglia are designated by numerals

x of f e alone . Anastomosis a branch o the third cer c of bral nerve , . 3 , the right side with a branch of the 2 18 second pedal , . e., eye . X .

PLATE VIII .

Parieto - visceral ganglia and nerves of Tethys cer v i na of of Dall and S impson . The contours the Organ

h h B er . c . ar e ad sc o. . Bo , , and the pericardial cavity, p , of s s indicated in dotted lines , that the reproductive y o of tem in light lines and unshaded . The anteri r end the animal is directed toward the upper side of the of of plate , the right the animal corresponds to the left

the plate , the preparation being drawn in ventral view .

- l l ar con . . v . r . . . p p . , right pleuro parietal connective ; p

- th e con . ar . v . . , left pleuro visceral connective ; p g ,

- or v is parieto Visceral ganglion complex , the ventral , ceral moiety concealing the upper parietal portion ; bi fu r cat r . l . r of . p , vulvar ne ve right parietal ganglion , f m . o ing into , which anastomoses with a branch the

ed I b . third pedal nerve , 3 p . , and , the vulvar nerve

- h r di os . os r 2 os a o . proper ; . p . , p ctenidial nerve ; p g ,

h r l I ct n i adia o. . . . ct e p ganglion ; g . , nerve to mantle ; g ,

l v . of dial ganglion ; . second nerve left visceral gang 2 its 2 a. b . lion ; , hepatic branch ; , its main branch forking 2 c to siphon and anus ; ., its recurrent branch to the peri t on eu m of B0 and the organ j anus , anastomosing beyond the latter with a branch of the third pedal nerve ; 3 d 2 e . of d p , the right side ; . , its branch to the posterior of B0 peritoneum , the branch to the organ l v of j anus ; . . third nerve left Visceral ganglion , supplying g . g ., the genital ganglion , and dividing into

v a . v b . . 3 , and . 3 , to the small hermaphroditic duct and ovotestis , and to the dorsal body wall respectively , other delicate minor branches noted in the text n ot being rep l . v f . . o resented fourth nerve left visceral ganglion ,

a. i s b . t 4 its branch to ventricle and pericardium, 4

ed . branch to kidney, pericardium and auricle . 3 p , of bifu r main trunk of third pedal nerve right side, cat a a ing into 3 and 3 b . 3 gives off 3 c to the organ of Boh ad sch , and 3f, which anastomoses with a branch of M the vulvar nerve , , and is distributed to the muscles of the body wall . 3b sends off 3d t o th e right retractor

PLATE IX .

Diagram of Central Nervous System of Tethys pu n c

Maz z ar elli tata seen from below, after . Diagram of Central Nervous System of Tethys d epilans

M zz r elli a a . ( Linn ) , seen from below , after Diagram of Central Nervous System of Tethys dacty

lom ela . ( Rang) , seen from below Diagram of Central Nervous System of Tethys cer

i . n D . v a all and Simpson, seen from below

The following abbreviations apply to all the ﬁgures of this l : c ...... plate g , cerebral ganglia ; p g , pedal ganglia ; p g , pleural m l v . or co ganglia ; . . g , left visceral ganglion , fused more less B of le el o. t . p y with its fellow , the right parietal ganglion ; , organ Boh a h r a d sc o . , hypobranchial gland ; 3p , third pedal nerve , , its b branch anastomosing with the right parietal ganglion, , its

Boh ad sch c or branch to the organ of , , its branch branches to the n to m . 8 a as muscles of the body wall , , also in ﬁgs 3 and 39 l 2 2 c v . mosing with the recurrent branch , , of the second nerve , . , 2 a of from the left visceral ganglion ; , hepatic branch second vis 2 b o t . ceral nerve, , its main trunk siphon and anus

X' PLATE .

Tethys cer v in a Dall and Simpson .

6 D f x . orsal view o shell . 4

Outline sketch of preserved specimen in dorsal View , mainly intended to show the general proportions and the markings surrounding the mantle pore . Tentacles

r h in O h or a and p es strongly contracted , the he d itself so 2 less . x .

D of - etail parieto Visceral ganglion complex from above , the two fused ganglia being rotated into side view , and all the nerves being more or less displaced to show

l con - con their mutual relations . p . p . ., pleuro parietal

ti e l con - r n ec v . v . . . ; p , pleuro visceral connective ; p . g l v right parietal ganglion ; . . g ., left visceral ganglion ; n r . I r . I a its p . , vulvar nerve ; p . ., branch a astomosing

t o an r . I b . with the third pedal nerve ; . p , its branch t er ior of r 2 os end large hermaphroditic duct ; . p . ,

! h r adio- os p ctenidial nerve ; p. g ., osphradial ganglion together with a portion of the integu ment cut ou t from

ct . os I the body wall ; . g , ctenidial ganglion ; p . g . , nerve to anterior and lateral regions of the mantle ;

' ct . n . cten idial n er v e l v I t o of , main ; . . , nerve vesicle or i 2 t s l v . Swammerdam , spermatocyst, and duct ; . , l . v . l . v . h e 3, 4, second , third and fourth nerves from t l t . x 20 lef viscera ganglion .

PLATE XI .

i i F r lan d Pl eu r obr an ch u s agass z i Mac a .

1 Shell in dorsal view . x 5 . D of 10 th 1 1th 12 orsal View , , and th elements of labial

h 2 0 . armature from 8th to 10 t rows . X 4 of Fig . 4 5 . Ventral view elements of labial armature from near 2 margin of 65th and 66th rows . X 37 . 6 of of of Fig . 4 . Ventral view bases elements labial armature

from middle portion . At this focus the hook and den l 2 0 tic es are not seen . X 4 . f 8. o Figs . 47, 4 Lateral views isolated elements of labial arma

x 2 . ture . 37

of r ow of . Fig . 49. Outermost lateral teeth eleventh radula

x 4 50 .

- ﬁ r - f 2 2 d . 0 st o Fig 5 . Twenty and twenty second lateral teeth row f o 0 . radula . x 4 5

' 1 16 1 n d h r . 1 f oh . a 8t of 1 ow o Fig 5 th , 7th , teeth 9th radula , li l u e . q y from above X 4 50 . 2 md r . I st 2 d r . of 1 ow Fig 5 , , and 3 lateral teeth 9th of radula ,

0 . obliquely from above . x 4 5

. f a 1 Fig . 53 Ventral view o b ses of 7th to 2 I st lateral teeth of 1 1th of x 0 . row radula . 4 5

Fig . 54 . Lateral View of glans penis and vaginal opening from

. v . x 12 below , vaginal Opening . .

PLATE XII .

- Pl u r br an ch u s a sizi i Ma F r l n . e o as c a a d . Figs . 55 57 g

D of of Fig . 55 . orsal view ganglia Central Nervous System , the ner ves and ventral commissures not being r ep r e

c l - sented . . p . g ., cerebro pleural ganglion ; p . g ., pedal

- c . . con . l ganglion ; p , cerebro pleural connectives ; p . p .

- con . e. , pleuro pedal connectives ; , eye and optic gang

2 8. lion . X 6 of d Fig . 5 . Outline mandibular armature . ., dorsal margin ;

a. v . x 2 8. , anterior margin ; , ventral margin .

- . . x 12 Fig 57 Ventro lateral view of right rhinophore . .

- o n M Far lan d D is c d or is br a n er i ac . 86 . Figs . 5 5

8. . 0 . Fig . 5 Mandibular armature X 3 dl s of 2 1 r o et . . Fig . 59. Anterior mandibular armature x 4 dlet of 2 1 60 . r o s . . Fig . Posterior mandibular armature x 4 61 of 16 of Fig . . Outermost lateral teeth th row radula in side

12 0 . view . x 62 of th r ow of Fig . . Outermost lateral teeth 7 radula , in side

120 . View . X th of 6 . Fig . 3 Typical lateral tooth from s row, in side View inner 2 1 face . x 4 . H of of a b 6 . Fig . 4 ooks armature glans penis , , in side View ; , 2 1 in front view . x 4 .

6 . Fig . 5 Reproductive organs from above, the parts slightly dis h d s o . . . placed as to show their mutual relations ,

h . am . hermaphroditic duct ; p , hermaphroditic ampulla ;

d v d r s . . o . . . . p , spermatic duct ; , oviduct ; p g , prostate

d . s . n c v v a . a. . gland ; . , deferens ; p , glans penis ; ,

- n d . of nidamental albumen gland complex ; . , duct nid

u d . c . . s . amental gland ; , uterine duct ; p , spermatocyst th a s . v . p , spermatotheca ; g , vagina , passing over prox

im all y into the vaginal duct , its distal portion laid open 10 by a triangular incision . x .

PLATE XIII .

i i n r l n d Dis cod or is v on h er gi MacFa a .

a b 6 an 66. . Fig . Labial armature , median ; , lateral plates ; ,

r i r t e o border . x 37 . Front View of three typical lateral teeth of ﬁrst r ow of 2 12 radula . x . Front view of three typical lateral teeth from middle of r o of 2 12 ﬁrst w radula . x . of 1 1th r ow of ob Outermost lateral teeth radula, li u l 2 12 e . q y from above x .

of - f d o . Outline cross section nidamental duct , dorsal ;

v 0 . , ventral ridge ; g, groove between them . X 5 Reconstruction from serial sections showing detailed f a o . h . . relations of the ducts the anterior genital mass , anterior end of hermaphroditic ampulla as it enters the

— s d nidamental albumen gland complex ; p . ., spermatic n s th duct emerging ; . d ., nidamental duct ; p ., spermato u d i s . s c t theca ; . , uterine duct ; p. ., spermatocyst , with

s c d . v a d duct , p . , leading into the uterine duct ; g . ., off t o f vaginal duct , cut short show the relations o the

underlying organs . The dotted oval upon the surface of the nidamental gland indicates the approximate of boundary the albumen gland .

PLATE XIV

od or is v on ih er in i MacFar lan d Disc g .

2 mu Fig . 7 . Reconstruction from serial sections showing the tual relations of the principal ducts and cavities within

- im the nidamental albumen gland complex . The less portant branches and all of the secretory alveoli of the of glands have been omitted , and are to be thought as ﬁlling the space between th e ducts represented and the of dotted line , which indicates the external contour the m h . a gland complex , as seen in side View . p . , the distal end of the hermaphroditic ampulla as it enters the i a h . . gland ; . , its intraglandular portion , dilating into u d ch . r . f . , the fe tilization chamber ; ., uterine duct ; l f x 1 a b . o . . , lumen albumen gland ; , duct connecting intraglandular portion of hermaphroditic ampulla with l a d . b . the lumen of albumen gland ; , albumen gland duct connecting the albumen gland with the lumen of i l n d . the nidamental gland ; . , lumen of nidamental d n . . gland ; , nidamental duct , cut across as it leaves the f gland . The cut end represents the thickness o the epi th elial of 6 . 1 . lining the , duct only x 5

Figs . 73 and 74 . Ventral and dorsal views respectively of the

reproductive complex . All connective tissue , nerves and blood vessels have been omitted for the sake of clear d f h . . o . h m a . ness , cut end hermaphroditic duct ; . p , d s . . n hermaphroditic ampulla ; p , Spermatic duct ; . g . ,

- id n d . nidamental albumen gland complex ; , nidamental

v a . v a d . u d duct ; g , vagina ; g . , vaginal duct ; . . , uterine t h . c s s . r . . duct ; p , spermatotheca ; p , spermatocyst ; p g ,

d . v . v as o prostate gland ; , deferens p . , penis ; p . . , ex of r t iu m v ae u o. ternal opening p p ; . , external vaginal

n d o. . f . o Opening ; , external opening nidamental duct .

x 36.

PLATE XV .

- D i cod or i on ih r in Ma Far l n 6. s s v e c a d Figs . 75 7 gi . w of o of Fig . 75 . S ide vie typical lateral to th from near center I s f 2 t row o radula . X 44 . 6 16 Fig . 7 . Four lateral teeth from inner end of th row, slightly 2 displaced . X 44 .

Pe tod or i r le M F r l n 2 l s ee i ac a a d . 8 . g y

2 Two typical spicules from dorsum . x 44 . of f Oblique View of base typical lateral tooth o radula . 2 82 x . f 1 2o h of . o t Fig 79. Outermost lateral teeth 9th and rows 2 radula . x 44 . f 1 2 o . Innermost lateral teeth 7th row of radula . x 44 of 282 Typical lateral tooth radula in side View . x .

Portion of anterior genital complex , the nidamental

d n h . . a and albumen glands having been removed . ,

t er i or of h r m h h . a/In e a end hermaphroditic duct ; p , p iti d r od c s . ampulla ; p . , spermatic duct entering prox f o r u d . imal end large prostate gland , p . , uterine duct, f c o s . off receiving the duct the spermatocyst , p , and cut just before its entrance into the nidamental gland ;

s th . v a d t p , spermatotheca ; g . ., vaginal duct , its dis al portion severed j ust before it dilates into the vagina ;

d . v . e of v as 10 f , proximal portion deferens . x .

PLATE XVI .

ili n r l n d Sp u r illo br az a a MacFa a .

1 16 Twelfth tooth of radula . x . 1 16 First tooth of radula . x . of Anterior end foot in ventral View, the extruded mouth region showing above . X 5 .

10 . Left salivary gland in side view . X

10 . Right salivary gland in side View . X 10 Anal papilla . X .

Median portion of typical tooth of radula . x

PLATE XVI I .

i r l n Sp u r llo br azilian a MacFa a d .

1 Figs . 90 and 9 . Outline sketches of preserved specimen from

- left and right sides . The dorso lateral cereta have all of been removed , the outline their bases showing their e relative position . The mouth region and reproductiv

openings are partly everted and much distorted , and

h n r i o h or s . the p e are strongly contracted x 5 .

2 of . a. Figs . 9 and 93 . Inner surfaces left and right mandibles , i i c b . . superior marg n ; , inferior marg n ; , posterior tip of d or masticatory process ; ., fulcrum, hinge , with single

e. crest in left mandible ; , the same , with double crest 16 in right mandible . x .

PLATE XVI II .

i ili an MacFar lan d Spu r lla br az a .

D of or of etail head, hinge region right mandible , inner

b . c. a. surface . , superior margin ; , inferior margin ; , the fulcrum , bearing double longitudinal crests bound ing a longitudinal groove , into which the single crest of ﬁ ts d of an the left mandible ; , ventral margin the t er i or f o . portion the masticatory process X 4 5 . D of of etail head region left mandible, inner surface . as c Lettering in preceding ﬁgure . The fulcrum, s x bears a single cre t . 4 5 .

PLATE XIX .

i i F r l n d Spu r illa br az l ana Mac a a .

Central Ner vous System from above . The buccal and Olfactory ganglia are n ot shown ; the basal ends of the l o . n . olfactory nerves , f , are seen arising from the cere

of - bral portion the cerebro pleural ganglion complex , c l I - . p . g . The nerves are indicated in Roman , VIII , of Tr i n ch ese in uniformity with the ﬁgures , cited in the ed ed com com text . p . g ., pedal ganglia ; p . ., pedal m i s r l com u c con su e cer . b . ; p . ., pleural commissure ; . ,

- t e. o . cerebro buccal connective ; , eye ; , otocyst , in front x 6 and slightly beneath it the otic ganglion . 4 .