Bull. Mus. natn. Hist. nat., Paris, 4e sér., 1, 1979, section A, n° 4 : 941-990.

Madagascar and Indian Océan Sipuncula

by Edward B. CUTLER and Norma J. CUTLER *

Résumé. — Une collection de plus de 4 000 Sipunculides, représentant 54 espèces apparte- nant à 10 genres, est décrite. Les récoltes furent faites par de nombreux scientifiques fors de diverses campagnes océanographiques de 1960 à 1977. La plupart de ces récoltes proviennent de Madagas- car et des eaux environnantes ; quelques-unes ont été réalisées dans l'océan Pacifique Ouest et quelques autres dans des régions intermédiaires. Cinq nouvelles espèces sont décrites (Golfingia liochros, G. pectinatoida, Phascolion megaethi, Aspidosiphon thomassini et A. ochrus). Siphonosoma carolinense est mis en synonymie de 5. cumanense. Phascolion africanum est ramené à une sous- espèce de P. strombi. Des commentaires sont faits sur la morphologie de la plupart des espèces, et, surtout, des précisions nouvelles importantes sont faites pour Siphonosoma cumanense, Gol- fingia misakiana, G. rutilofusca, Aspidosiphon jukesii et Phascolosoma nigrescens. Des observations sur la répartition biogéographique des espèces sont données ; 10 espèces (6 Aspidosiphon, 2 Phas- colion, et 2 Themiste) provenant d'aires très différentes de celles d'où elles étaient connues anté- rieurement sont recensées. Abstract. — A collection ot over 4000 sipunculans representing 54 species in 10 gênera is described. The collections were made by numerous individuals and ships during the 1960's and early 1970's, most coming from Madagascar and surrounding waters ; a few from the western Pacific Océan ; and some from intervening régions. Five new species are described (Golfingia liochros, G. pectinatoida, Phascolion megaethi, Aspidosiphon thomassini, and A. ochrus). Sipho- nosoma carolinense is submerged as a junior synonym of S. cumanense. Phascolion africanum is reduced to a subspecies of P. strombi. Morphological commentary is provided on most species but significant new information is offered for Siphonosoma cumanense, Golfingia misakiana, G. rutilofusca, Aspidosiphon jukesii, and Phascolosoma nigrescens. Zoogeographical observations are presented ; ten species (six Aspidosiphon, two Phascolion, and two Themiste) are herein reported from areas significantly différent from their earlier known ranges.

INTRODUCTION

The information presented in this paper is based on material collected by numerous persons over several years time. The largest single collection was made by Dr. B. A. THO- MASSIN, Station marine d'Endoume (SME) et Centre d'Océanographie, Marseille, in the coral reef complexs of the région of Tuléar (mainly on the " Grand Récif " barrier reef and lagoon, ofî Tuléar) and on the fringing reefs around Nosy Bé, S.W. and N.W. Madagas- car (see THOMASSIN, 1969, 1971, 1973). P. GALENON (SME) studying samples made by the last researcher (BT) on the Tuléar coral reef boulder tracts also contributed some material from this région (see GALENON, 1977). Dr. R. PLANTE (SME) provided us with some subtidal

* Utica Collège of Syracuse Unwersity, Utica, New York 13502 USA. — 942 — collections in the Nosy Bé area. The remainder of the collections were made during the International Indian Océan Expédition (1963-1964) and processed by the Smithsonian Océanographie Sorting Center (SOSC). Thèse were collected by several vessels (especially the " Anton Bruun " and " Te Vega ") and persons. The funding for the U.S. program in biology of the IlOE was provided by the U.S. National Science Foundation. There is a large body of literature on the Indian Océan sipunculan fauna. HALDER (1975) and the monograph by STEPHEN & EDMONDS (1972) contain thèse références. The fauna of Madagascar was most recently reviewed by CUTLER (1965). The 54 species included in this report, representing 10 of the 14 gênera, are listed in table 1 along with a notation on their zoogeography. Five species new to science are described and named ; three others are described but not named. Complète descriptions of the established species are not presented but can be found in STEPHEN & EDMONDS (1972). Table 1 shows that nine species are represented by more than 100 spécimens, nine by 20-100, 14 by 10-19, and 22 by less than 10 spécimens. Ten of the 46 established species are reported from régions significantly outside their previously known range, while 23 are reported from new localities but generally within their normal range. Important new information is presented for a few species where morphological studies of numerous spéci- mens was productive. There is one noteworthy example of how luck, fate, or the stars sometimes plays a rôle in science. " Anton Bruun " Sta. 407 I oif north-western Madagascar contained five species from four différent gênera. At first we thought there was some mistake as the gear listed from this station was a hand line. After checking, it turns out that someone using a hand line, hooked a 66 pound head of coral from 58 m of water and hauled it up ; a particularly fortuatous incident. The really interesting feature is the striking similarity between this station and one made on the other side of the océan on the Cocos-Keeling Islands (Sta. B-5). This was in a lagoon oif Direction Island in 10-20 feet of water with large Porites heads. Four of the five species found at 407 I were also found here. A second Cocos-Keeling station (B-3) contained two of thèse four (Lilhacrosiphon maldwensis and Aspidosiphon steenstrupi) and thèse two are not found anywhere else in thèse collections. A third species (Aspidosiphon ochrus) is a new species and found at only two other localities. The fourth species common to the two areas is Cloeosiphon aspergillus. The biological similarity between thèse two widely spaced areas is intriguing. The apparent absence of thèse species in the intervening space is also curious and the luck of finding this one head of coral certainly should make ail zoogeographers once again qualify their conclusions with a clear message that what we know is not necessarily what is. In the systematics section most of THOMASSIN'S stations (BT) are from the Tuléar and Nosy Bé (Enhalus acoroides seagrass beds) régions or from the Tiahura reef complex, Moorea Island, French Polynesia 1 (Moorea BT) ; exceptions will be noted. P. GALENON'S (PG) are from the greater Tuléar région and PLANTE'S (BP) are from within 80 km of Nosy Bé Island. The IIOE station data is included with each species. We have also included a few other Pacific Océan records : collections made by M. A. CHARTOCK, Univ. Southern California, Los Angeles, on Eniwetok atoll, Marshall I.

t. Studv donc in joint research programm with the Antenne of the Paris Muséum-EPHÉ of Tahiti, in July 1973. — 943 —

Table 1. Species included in this report. ^a'symbols for zoogeographical notation: A- Thèse records consistant with earlier ones; B- From new localities but previously reported from the Indo-West Pacific; C- Significant exten- sions of known range; X- No comparative data.

Species Number of Number of Zoogeographical Species "Number of Number of Zoogeographical stations spécimens notation (a) stations spécimens notation (a)

SIPUNCULIDAE ASPIDOSIPHONIDAE

Sipunculue Aspidosipkon

S. aequabilis l 1 A (Aspidosipkon s.s.)

S. indiens 3 5 A A. elegans 4 15 B

S. longipapillosus II 12 A A. exhaustus 6 i ; C

S. norvégiens 2 3 A A. jukesiî 68 503 B

S. nudus 1 1 A A. kovaleskii 4 13 B

S. titubans 7 14 B A. venabulus 7 17 C

Siphonosoma A. zinni 1 5 C

(Damosiphon) A. therassini sp. nov. 63 241 X

S. eumanense 123 408 B (Paraspidcsiphoni

(Hespcrosiphon) A. angulatus 2 19 c

S. vastum 4 7 B A. klunzingeri. 8 16 c

(Siphonosoma G.s.) A. speeulator 8 .22 c

S. australe 6 25 A A. steenstrupii' 3 14 A

OLFINGIIDAE A. trunaatus 1 3 A

Golfingia A. oohrue sp. nov. '. 14 X

(Golfingia s.s.) Lithaorosiphon

G. murieaudata 2 3 A evistatus 1 B

G. vulgaris 1 l B L. maldivensie 3 9 B

G. lioohroB sp. nov. S 8 X Cleo

G. peclinatoida sp. nov. 23 130 X C. aspergillus 36 420 A

(Golfingielia) Centrosiphon

1 G. pudioa (. u C. speoies 3 3 X

(Fisherana) PHASCOLOSOMATIDAE

• 'J. " '.• :' ; Phascolosoma

(U-ito siphon) (Satonus).

G. trzchocephala P. peotinatum

(Phascoloides) (Phaseolosoma s.s.) V) G. minuta P. albolineatum 2 2 6 23 66 G. vutilofusca. P. agassizii 2 3 3 10 G. speoies P. funafutiense 3 21

Phascolion P. nigrescens 58 180

P. paeifioum P. beklemischevi 1 18 49 P. perlueens P. pharetratum 15 37 P. scolops P. strombi africanum B 49 227

P. valdivae J

F. r;,:gaethi sp. nov. 5

P. speoies 1 TOTAL OF SPECIMENS

Themiste

T. lagenformis 2

T. lissa

T. minor

T. robertsoni

NOTE ADDED IN PRESS : In CUTLER, 1979, Mitosiphon and Fisherana are combined into Apionsama and Phascoloides is changed to Nephasoma. — 944 —

The habitat and ecological position of many of thèse species will be outlined in more détail in forthcoming publications of B. THOMASSIN 1. In addition to those persons already named, we are indebted to ail the many people who made thèse collections and to the staff of the SOSC for processing much of it. Most of this work was done at Duke University Marine Laboratory while on sabbatical leave from Utica Collège. The artwork was done by Mr. Henry IWANICKI, Utica.

Sipunculus aequibilis Sluiter, 1902

IIOE Sta. 17, 1 spec. ; 3/21/63 ; 7°38' N, 97°08' E ; 510 m ; Strait of Malacca.

This single spécimen has 21-23 longitudinal muscle bands and free nephridia which open slightly anterior to the anus between bands 4 and 5. The retractor muscles are slender with the ventral pair originating from band 3 and the dorsals from bands 8 and 9. In STEPIIEN & EDMONDS (1972 : 25) the statement is made that the introvert is " ... about one eighth as long as the trunk ". SLUITER (1902) described this as heing one fourth the trunk length. This worm has a 55 mm trunk and a 14 mm introvert.

DISTRIDUTION. — This record lits in well with previous ones as a deeper water member of this genus. It has been recorded from the Mediterranean Sea, Gulf of Aden, Laccadive Island, Bay of Bengal and Indonesia from depths of 26-1686 m, most being several hundred meters. This species appears to be restricted to deep water and with the exception of the Mediterranean Sea record is, so far, an Indian Océan form.

Sipunculus indicus Peters, 1850

IIOE Sta. JR-8 ; 3 spec. ; 12/23/63 ; 13°24' S, 48°22' E ; 1 m ; Nosy Bé. Tuléar BT Sta. : Port Tuléar ; 1 spec. ; 839, 1 spec. Lagoonal bottoms and littoral sand banks.

The thrce worms from Sta. JR-8 and the one from Sta. 839 arc in good, " normal " condition and are easily assigned to this taxon. The one from Sta. Port Tuléar had dried out at some point and the internai organs were destroyed. It docs have 40-41 longitudinal muscle bands and is placed herc with some réservation. The fishermen in the Tuléar région use this species for bait as has been recorded elsewhcre (CUTLER, 1965).

DISTRIDUTION. — This has been previously recorded from Madagascar as well as from neighboring east and south Africa through the Indian Océan, the South China Sea, and several West Pacific Islands. It is a shallow water species and a représentative of the Indo-West Pacific shallow water province.

1. For thèse results see : B. A. THOMASSIN (1978), Les peuplements des sédiments coralliens de la région de Tuléar (S. W. de Madagascar). Leur insertion dans le contexte côtier indo-paci(ique. Thèse Doct. ès-Sci., Univ. Aix-Marseille II, 22 avril 1978, Archives originales du CNBS, n° A.O. 11.581 : 494 p. multigr., 180 tabl., 209 fig. + Annexe méthodologique : 101 p., Annexe faunistique : 302 p. — 945 —

Sipunculus longipapillosus M urina, 1968

IIOE Sta. 243B : 1 spec. ; 11/28/63; 24°54' N, 61°48' E ; 107 m; S. of Karachi. — Sta. 254B; 2 spec. ; 11/30/63 ; 25°35' N, 57°09' E ; 256 m ; Gulf of Oman. — Sta. 255A ; 1 spec. ; 11/30/63 ; 25°48' N, 57° 07' E ; 93 m ; Gulf of Oman. - Sta. 261A ; 8 spec. ; 12/01/63 ; 25°53' N, 56°53' E ; 99 m; Gulf of Oman.

This species with the girdle of long papillac in the mid-trunk région is quite distinctive. Thèse animais with 24-29 longitudinal muscle hands, spindle and fastening muscles, and much connective tissue anchoring the gut coil to the body wall, ranged in trunk length from 35-102 mm. The papillated région of the trunk ranged from 30-75 % of the trunk, most covering about 50 %.

DISTRIBUTION. — The two previous records of this species are from this saine gênerai area, the Red Sea at 368 m and the Gulf of Oman at 199 m. This would seem to be a very loca- lized species along the edge of the photic zone in the northwestern part of the Indian Océan. However, there is a récent unpublished record from the Gulf of Mexico ofî Panama City, Florida.

Addendum : Since completing this manuscript, two additional spécimens were sent to us by Dr. II. ZIBROWTUS (SME) from the southern Red Sea collected during the Suidit Campagne Same- rouad N.O. " Suroît " on 30/1/77. The station was at 14°44' N, 42°27' E at depths of 350-700 m. Thcy are both in good condition and fit the above comments.

Sipunculus norvegicus Danielssen, 1868

IIOE Sta. 409E; 1 spec.; 10/10/64; 16°11' S, 43°42' E ; 62 m ; NW Majunga, Madagascar. — Sta. AB19 ; 2 spec. ; 3/23/63 ; 8°30' N, 97°58' E ; 42 m ; SW of Sumatra.

Thèse three worms exhibit the typical 22-24 longitudinal muscle bands, nephridia opening a little anterior to the anus, and unattached for most of their length. The ventral retractor muscles originate from longitudinal muscle bands 2-4 and the dorsals from 9-10.

DISTRIBUTION. — This species is common in cooler waters of the North Atlantic as far south as the Carolinas on the western side and West Africa and Cape Verde Islands in the east. Thèse records fit in with scattered reports from the Suez Canal, East Africa and Madagascar, over to Indonesian waters, Loyalty Islands and Hawaii and suggest it is more widely distributed. Most of the records are from 50-1500 meters.

Sipunculus nudus Linnaeus, 1766

Nosy Bé BT Sta. 557 ; 1 spec. ; Enhalus acoroides patch.

This pinkish grey spécimen measured 39 X 10 mm but had its posterior end ampu- tated during collection so is incomplète. The surface shows the typical Sipunculus confi- — 946 — guration. The circular muscles are well defined and 33 longitudinal muscle bands are présent.

DISTRIBUTION. — This is the nearest thing to a cosmopolitan species in this genus having been reported from shallow subtidal waters in the tropical and sub tropical areas of ail the world's océans including the Mediterranean and Red Seas. A single report (HALDER, 1975 : 55) from the Laccadive Islands at 2 308 m seems out of the norm for this species.

Sipunculus titubans Selenka, de Man & Bulow, 1883

Tuléar Bt Sta. : 777A, 1 spec. ; 788, 1 : 790, 1 ; D30, 1 (damaged). Moorea BT Sta. : 19, 2 spec. ; 27, 2 ; 29, 4.

As STEPHEN & EDMONDS (1972 : 38) point out, this is a confusing species. Thèse 17-50 mm spécimens have from 24-30 longitudinal muscle bands and fit the description fairly well. In several, the nephridia are unattached, in one they are attached for about 1/4 their length, and in one, they are attached for 1/2 their length as they are described. The position of the anus and the nephridiopores varies from both being at the same level, to the anus being 2 mm anterior to the nephridiopores. In the animal from Sta. 790 the circular muscles are more prominant than the longitudinal and the worm from Sta. 788 has a cluster of several large (4 mm long in a 50 mm worm) finger-shaped outgrowths from its rectum. The eight Pacific Océan worms ail had 24-25 longitudinal muscle bands and could easily be confuscd with S. norvegicus.

DISTRIDUTION. — This species appears in the Caribbean, off the Canary and Cape Yerde Islands and tropical West African waters, then off Zanzibar, Madagascar, Siam (Thailand), in the East China Sea and the Pacific coast of Costa Rica. Thèse records support a construct of a shallow water, tropical species now absent from only the eastern Indian Océan.

Siphonosoma (Damosiphon) cumanense (Keferstein, 1867)

Siphonosoma carolinense Fischer, 1928 : 138-140 ; STEPHEN & EDMONDS, 1972 : 44-46. Siphonosoma novaepomrneraniae Wcsenberg-Lund, 1959. IIOE Sta. : RU-2 ; 4 spec. ; 8/20/64 ; 25°50' S, 32°55' E ; 1 m ; Inhaca, Mozambique. — HA 67-32 ; 1 spec. ; 8/5/67 : 7°21' S, 72°28' E ; 1 m ; Diego Garcia. — HA 67-40 ; 4 spec. ; 7/10/67 ; 7°21' S, 72°28' E ; 1 m ; Diego Garcia. Nosy Bé RP Sta. : 7, 1 spec. ; 10, 2 ; 12, 1. — BT Sta. : NSB 9, 1 spec. ; 552, 6 ; seagrass beds. Tuléar PG Sta. : many on the outer boulder tracts of reefs. — BT Sta. : a lot, mainly m the sédi- ments of the outer boulder tracts, the sandy bottoms of inner pools, the seagrass beds, on the barrier reef, few in lagoon bottoms, and in the littoral tidal flats with or without seagrass beds and mangrove.

This collection of 329 worms from a single population (Tuléar stations) provided a valuable analytical base for some troublesome points. As STEPHEN & EDMONDS (1972 : 44) — 947 —

state : " The species in this subgroup are remarkably alike and it is possible that they are synonymous. " They proceeded to reduce six names down to three : S. edule, S. cumanense and S. carolinense. The first diiïering from the others due to a shorter introvert and the remaining two differentiated by a diiïering number of tentacles. The following comments are based on an analysis of 306 worms from Tuléar, four from Inhaca, some from Nosy Bé (CUTLER, 1965), and GEROULD'S (1913) from Florida. The measurements taken were based on a subset of 45 entire worms ranging in size from 3-230 mm, many others had been damaged during the collection process and were incomplète.

Ratio of introvert to trunk length. Of the three species in this subgenus, S. edule report- edly has a trunk 8-14 times the length of the introvert. the other two having longer intro- verts. The trunks in this group ranged from 1.2-4.7 times the introvert length with a wide spread of values through the middle sized worms. EDMONDS' data from my Mada- gascar worms shows a higher slope with values ranging from 2.5-7 times the introvert length. The table in STEPHEN & EDMONDS (1972 : 47) has an error : it stales millimeters where it means centimeters in the headings. At any rate, if the S. edule data is true, per- haps there is a real différence as none of thèse introverts were that short. If one converts thèse measurements to détermine what percentage of the total length is made up of introvert (i.e. if the trunk is 3 times the introvert length then the introvert

50

20 40 60 S0 100 120 W0 160 1S0 200 210 TRUNK LENGTH (IN MM)

FIG. 1. — The relationship between trunk and introvert length in Siphonosoma cumanense. Simple linear régression (Y = a + bx), a = 38.4, b = -0.13. — 948 —

is 25 % of the total) it becomes obvious that larger worms have proportionately smaller introverts (fig. 1). This would appear to be a clear example of allometric growth (a not uncommon biological phenomenon) where the trunk grows at a faster rate than the introvert. Extrapolating from the data shown in figure 1 it is possible that large S. cumanense (over 250 mm trunk) would have an introvert small enough to approach the 7-11 % range reported for S. edule. The unanswered question then becomes : are S. edule only very large 5. cumanense or S. cumanense with unusually short introverts ?

Tentacle number. S. carolinense difîers from 5. cumanense according to STEPHEN & EDMONDS (1972 : 44) by having 60-80 tentacles instead of 25-30. In this population we found it very difïicult to make an accurate count of the tentacles, especially as most had retracted introverts. Also, there may be some confusion due to the bifurcated nature of thèse structures. We counted the tips, not the bases. The range we found was from 14- 120, most between 25 and 45 with a spread of values in the middle sized worms. The smallcst have the fewest and the largest have the most, very few having 60 or more (15- 20 % of the sample).

Transverse dissepimenls. Supposedly ail the species of this subgenus have thèse sheets of connective tissue transversing the coelom. However, this is probably the most variable of the variables in thèse worms. They were not discernable in ail worms, and when présent, their number, distribution, strength, height, etc. were very différent from one worm to the next and with no apparent relationship to size or state of contraction/relaxation. Sometimes strong, then weak ; high from the body wall, then low to it ; many, then few ; some spread over a wide area, then others restricted to a few short patches. In one 17 mm worm they were easier to see than in a 215 mm worm. Those with undiscernable dissepiments ranged in size from 3-110 mm. I suspect that in the past, other authors with few animais may well have overlooked thèse, and I seriously wonder about the logic of giving such a dilïi- cult and variable trait subgeneric value. Also, S. novaepommeraniae is exactly like S. cuma- nense except it lacks the transverse dissepiments. WESENBERG-LUND (1959a) says they exist in her Mauritius forms of S. novaepommeraniae and even draws them. Hers then should be considered S. cumanense and possibly FISCHER'S (1926) should be here also.

Nephridiajanus relationship. Measurements were taken and in ail cases the nephridia were anterior to the anus, from 1/2-7 mm. Again, the smallest have the least distance between them and the largest have the most, but in the middle range there is a large spread with most showing 1-3 mm space between the two openings.

Retractor origins. In ail the spécimens the ventral and dorsal retractor muscles came from the same anterior/posterior level.

Anastomosing. The anastomosing of the longitudinal muscle bands occurred only very rarely, perhaps 2-6 times in any one worm and more commonly in worms over 100 mm long. As a rule one has to look hard to find any.

In view of the above discussion, the minor différences between S. cumanense and S. caro- linense, and the overlapping distribution, we suggest that 5. carolinense be considered a junior synonym of S. cumanense. — 949 —

DISTRIBUTION. — This common species has been previously reported from Madagascar, East and South Africa as well as several other Indian Océan locations up into the Red Sea. It is found in Indo-China up to Japan and China and down to Australia to New Guinea and several West Pacific Islands. It also occurs in the western Atlantic from Florida to Venezuela. It seems to be absent from the eastern Atlantic and Pacific.

Siphonosoma (Hesperosiphon) vastum (Selenka, de Man & Bulow, 1883)

IIOE Sta.KA-9 ; 1 spec. ; 11/18/64 ; 4°05' S, 39°14' E ; 1 m ; Mombassa, Kenya. Tuléar BT Sta. 751A, 1 spec. — MC Sta. 12 ; 1 spec. : 8/28/70 ; 11°21' N, 162°22' E ; 1 m ; Eniwe- tok. — HA 67-40 ; 4 spec. ; 7/10/67 ; 7°21' S, 72°28' E ; 1 m ; Diego Garcia.

In this subgenus there are only three species, ail having fringes or club-shaped caecae on the rectum. The présence of rings of pale introvert hooks and numerous caecae easily distinguish this form. There are four retractor muscles and a posteriorly attached spindle muscle. Transverse dissepiments are lacking as are contractile vessel villi. The longi- tudinal musculature is arranged in 27-28 bands.

DISTRIBUTION. — This shallow water Indo-West Pacific form has been recorded several times from Mauritius through the Indian Océan, Indonesia, Australia and several West Pacific Islands. This is the first record from any of thèse locations.

Siphonosoma (Siphonosoma) australe (Keferstein, 1865)

Tuléar BT Sta. : 3, 8 spec. ; 5, 9 ; 7, 3 ; 8, 3 ; 9, 2 ; 673, 1 pièce with hooks ; littoral tidal flats without seagrass beds.

Thèse 25 worms range in trunk length from 15-120 mm and as they have no dissepiments in the body cavity or numerous rectal caecae, easily fall into this subgenus. The large, pointed, spine-like hooks on the introvert and single rectal caecum characterize this well known species. The nature of the fixing muscle with three branches shows up very nicely.

DISTRIBUTION. — This is another Indo-West Pacific shallow water species having been recorded from Durban, Zanzibar, Madagascar, through India to Indonesia, Australia, New Zealand and a few West Pacific Islands.

Golfingia (Golfingia) muricaudata (Southern, 1913)

IIOE Sta. 369C; 1 spec; 8/17/64; 23°48' S, 37°46' E; 2200 m; Mozambique Channel. — Sta. 370D ; 2 spec. ; 8/18/64 ; 24°28' S, 35°36' E ; 880 m ; Mozambique Channel.

Thèse animais with four retractors and a short caudal appendage (2 mm in a 15 mm worm) are the same as found in the Atlantic Océan (CUTLER, 1973). The worm from Sta. 369C had its introvert missing, but the others were intact and without hooks. DISTRIBUTION. — This deep water species has been collected at widespread localities in the north Atlantic and Pacific Océans including Hudson Bay, from the Atlantic coast of South America and Bouvet Island in the South Atlantic. This record confirms its pré- sence in this southwest corner of the Indian Occan. This is the closest thing to a bipolar species in this report as ail the records have been outside the 20° north and south latitudes. Thèse depths fit into the known vertical distribution of 450-3000 m.

Golfingia (Golfingia) vulgaris (de Blainville, 1827)

IIOE Sta. 392K ; 9/10/64 ; 29°19' S, 31°36' E ; 38 m ; off Durban OR. — 391C ; 9/9/64 ; 29°29' S' 31°45' E ; 86 m ; (label confusion at SOSC) 1 spécimen.

This worm shows the typical pale trunk with light brown pigmentation on both ends, much of it being covered with low, flat papillae or skin bodies which look like clear spots when viewed with transmitted light. Internally the normal arrangement of organs is found and the introvert hooks measure 80-90 [xm in height.

DISTRIBUTION. — This is an East Atlantic-Indian-West Pacific Océan species with its density being highest off Europe and West Africa and through the Mediterranean with occasional reports through the Red Sea, Zanzibar but then skipping across to Malaya, East China Sea, Singapore, Australia and Japan with an Antarctic and Kurile-Kamchatka Trench record also. This is the most southerly record for this area.

Golfingia (Golfingia) liochros n. sp.

Golfingia (Golfingia) n. sp. Cutler, 1977. IIOE " Te Vega " Sta. 82 LU 10 ; 1 spec. ; 11/6/63 ; 9°26' N, 97°54' E ; 1 m ; Thailand. Tuléar BT Sta. : 634, 1 spec. ; 654B, 1 ; 755, 1 ; 781A, 1 ; 782, 1 ; 797, 1 ; 801, 1. More frequently located in the sédiments clogging the outer boulder tracts of the barrier reef ; one time sampled in a seagrass bed.

Thèse worms are the samc as an unnamed Golfingia (Golfingia) from Mozambique partially described in CUTLER (1977). They have a striking external appearanec : the trunk is smooth, slippery whitc or pink while most of the introvert and posterior end of the trunk are covered with densely packed, uniform sized, spheroid to digitiform, yello- wish-orange papillae, giving thèse régions a granular look (fig. 2). When the introvert is rctracted the papillated areas may look somewhat shield-like. The introvert, which is shorter than the trunk, becomes transparent at the distal end and bears scattered hooks measuring 40-120 u.m along their longest axis. One worm has its introvert completely extended and six tentacular lobes are discernable. The trunk dimensions are 5-19 mm long by 0.5-3 mm wide. The variations in color of the papillae in thèse worms may be due to différent postmortuni chemical environments. Those collected by the " Galathea " were brown, the Tuléar worms were pale orange and the " Te Vega " worm was off white. The smallest one from Sta. 654 has a transparent body wall and the papillae are only slight- — 951 —

FIG. 2. — Golfingia liochros n. sp. Whole animal, introvert partially extended. (Scale = 2 mm.) ly pigmented. This is placed hère with some réservations. The hooks follow the same trend i.e., those from the " Galathea " worm were dark, the Tuléar worms were paler and in the " Te Vega " worm the hooks were very light colored and almost clear. Internally there are four retractor muscles. The ventral pair are three to four times the diameter of the dorsals and originate at about the middle of the trunk, while the finer dorsal pair originate half way between the middle of the trunk and the anus. The single lobed, tubular nephridia are free from the body wall, one third to one hall' the length of the trunk, and open at the level of the anus. The spindle muscle is présent but not attached posteriorly. A single fixing muscle is présent attaching the third gut coil to the body wall near the origin of the right dorsal retractor muscle. No rectal caecum was observed but along the contractile vessel, while it is still associated with the retractor muscles, are a few pale orange bubble-like swellings or vesicles ; not villi. A pair of pigmented eyespots is présent on the brain. In this subgenus two species have been described with hooks, tentacles, " normal " retractor muscles, and an Aspidosiphon-hke shield at both ends of the trunk : G. sanderi and G. scutiger. In addition to the différent nature of the " shields " and position of the ventral retractor muscle origin, the well defined hooks not arranged in rows set this form apart from thèse other two. The name liochros was chosen from the Greek meaning smooth- skinned.

The type spécimen has been deposited in Muséum national d'Histoire naturelle, Paris. Holo- type : Cat. N° AI 1-411 ; BT Station 755 ; " Grand Récif", Tuléar, Madagascar.

DISTRIBUTION. — " Galathea " Sta. 214 off Beira, Mozambique, 20°10'S, 35°15' E at 380 m in clay, plus thèse records from Tuléar, Madagascar, and off Thailand.

Golfingia (Golfingia) pectinatoida n. sp.

Tuléar BT Sta. : 121, 6 spec. ; 236, 1 ; 256, 1 ; 259, 6 ; 654, 11 ; 654 B, 1 ; 751A, 3 ; 752, 2 ; 755, 13 ; 757, 11 ; 782, 6 ; 784, 18 ; 788, 13 ; 795, 2 ; 797, 3 ; 801, 22 ; 803, 1 ; 811, 5 ; 831, 1 ; 852, 1 ; 870, 1 ; 916, 4. Most of the spécimens were collected in the sédiments clogging the outer boulder tracts on the barrier reef ; others samples are from sédiments of the outer reef slope, reef flats and enclosed lagoon slope. Moorea BT Sta. : 16, 1 spec. ; 19, 2. FIG. 4. — Golfingia peclinatoida n. sp. : A, tentacles and tip of introvert ; B, introvert hook (scale = 10 (Jtrn). — 953 —

The trunk and most of the introvert are uniformly covered with large, low, oval, blister-like papillae. The size of thèse are directly relatcd to the size of the animal. Their density is low enough so that the borders arc not in contact with their nearest neighbors. The epidermis of many animais is rugose and loose appearing, often with wavy, zig-zag lines reminiscent of G. calharinae (fig. 3). The overall color ranges from white through tan to pinkish tan, most being a very pale tan. The length of the trunk ranges from 4-

FiG. 5. — Golfingia peclinatoida n. sp. Internai view. ie -— intestinal coil ; ldr -- left dorsal retractor ; n = nephridium ; r = rectum ; rvr = right ventral retractor ; vnc = ventral nerve cord.

1, 8 — 954 —

21 mm in this population. The diameter is usually 2-3 mm while the introvert is usually 1.5-2 times the length of the trunk. Normal Golfingia tentacles are présent. In one worm with a 15 mm trunk and 25 mm introvert, there are 24-28 short tentacles présent (fig. 4A). Colorless hooks, measuring 25-30 u,m in height are arranged in several rows (30 rows in the above worm) becoming scattered posteriorly. They are sharply bent with 4-6 (most have 5) spinelets at the base (fig. 413). Internally, the four slender retractor muscles originate in the first quarter of the trunk with the ventral pair anterior to the dorsal (fig. 5) in an atypical fashion. The use of dorsal and ventral here is perhaps misleading as both pairs originate quite close to the ventral nerve cord and the actual différence between the two is slight. The long, free nephridia have a short secondary lobe anterior to the nephridiopore which itself may be located near the levé! of the ventral retractor muscle origins or anterior to this point. The anus is posterior to the nephridiopore in the région of the retractor origins. The intestine is not anchored by a spindle muscle or fixing muscles. While most of thèse were free living in the sédiment, a few were inhabiting empty gastropod shells. The other members of this subgenus which have hooks, normal tentacles, no Aspi- dosiphon-Wke shields, and a rugosc wrinkled epidermis are G. mutabile and G. rugosa. The nature of the retractor origins, nephridia, papillae, and hooks with spinelets easily distinguish this species from ihose 1 wo. The similarity of this species to those in t lie subge- nera Milosiphon and Fisherana (spinelets on hooks and bilobed nephridia) is interesting. The absence of a posteriorly attaehed spindle muscle in this species clearly séparβtes thèse groups. Whether or not that particular character deserves such heavy weighting may be debatable. Perhaps this set of characters (bilobed nephridia, four thin retractor muscles, and spinelets on hooks) that we see in this form and in others such as G. niisakianajhespera, G. murinae, and Phascolosoma pectinata is simply an example of convergent évolution. It would be interesting to know if there was any adaptive value to spinelets on the hooks. Except for the tentacles and longitudinal musculature, this species is strikingly similar to P. pectinata, hence its name.

The type spécimen has been deposited in Muséum national d'Histoire naturelle, Paris. Holo- type : Cat. n" AH-409 ; BT Station 801 : " Grand Récif", Tuléar, Madagascar. Paratype : Cat. n° A11-4.10 ; BT Station 757; ''Grand Récif", Tuléar, Madagascar.

Golfingia (Golfingiella) pudica (Selenka, 1885)

IIOE Sta. 371E : 6 spec. ; 8/19/64 ; 24°46' S, 35°20' E ; 132 m ; Mozambique Channel.

Thèse représentatives of this uncommon and ill defined species are ail small (2-12 mm trunks) and not in particularly good condition. As thèse spécimens have the spindle muscle attaehed posteriorly, we are in agreemenl with WESENBERG-LTJND (19596) and place them in this subgenus (see CUTLER éV MURINA, 1977). The skin is loose fitting, thin, and pale brown/grey. In some it is wrinkled and exhi- bits transverse grooves. Numerous flat, pale papillae cover the surface. The introvert is a little longer than the trunk and bears rows of thin, pale, unidentate hooks 25-30 u,m — 955 — high. Some of thèse hooks exhibit 3-4 basai plates at the anterior margin that appear occasionally like the start of spinelets. The four thin retractor muscles have the normal arrangement, the ventral pair origi- nating near the middle of the trunk and the dorsal pair originating more anteriorly, about half way between the ventrals and the nephridia. The short, single-lobed nephridia open at the same level as the anus and hang free in the coelomic cavity. A pair of eyespots is présent. The original description of this species by SELENKA is woefully brief and inadéquate. He compared it to G. culgaris but did not provide a real description nor any helpful figures (see STEPHEN & EDMONDS, 1972 : 104). Also, it is very similar to Golfingia (Fisherana) capitata and without an accurate grasp of the tentacular arrangement a G. capitula would key out to G. pudica. It might also be notcd that this species co-occurs hère along with Aspidosiphon zinni (the only record for this species from this région). A. zinni co-occurs with G. capitata off castern United States. Therefore, thèse spécimens are assigned to this taxon with réservations.

DISTRIDUTION. — The three previous records are from fairly cool, sublittoral water off Antarctica, Kerguclan Island, and Mauritius, so this is an additional record of an appa- rently southern océan form.

Golfingia (Mitosiphon) misakiana (Ikeda, 1904)

IIOE Sta. JR 38-1 : I spec. : 1/20/6'. ; 13°24' S, 48°18' E ; 1 m ; Nosy Bé. — Sta. RU 242 ; 3 spec. : 11/14/64 ; 04°05' S, 39°40' E ; 1 m ; Mombassa. Nosy Bé BP Sta. : 4, 8 spec. — BT Sta. : 550, 1 spec. ; 557, 2. Enhalus acoroides seagrass beds. Tuléar BT Sta. : Many, niainly in the médium and coarse sands on the reefs and lagoonal bottoms. Moorea BT Sta. : 27, 12 spec. ; 29, 11 ; 33, 4.

Thèse 535 spécimens make this troublesome species the most common form in thèse collections. The Golfingia trichocephalajmisakianajhespera complex is one of the less clear corners of sipunculan systematics at this point. They have been discussed by a few authors (e.g. CUTLER, 1973 ; AMOU, 1975) and more will be soon fortheoming. The basic distinction has been that G. trichocephala lacks hooks while the other two have hooks. The alleged différences between G. misakiana and G. hespera are thought to be papillae and/or number of accessary spinelets on the base of the hook. We found that most hooks in thèse spécimens had from 4-6 spinelets. A review of this controversy will appear in CUTLER (1979). This subgenus lias been redefined because of the récent discovery that at least two species have the tentacles dorsal to the mouth (fig. 6). It is very dillicult to détermine the présence of hooks if the introvert is not everted sufficiently as the introvert is more than eight times the trunk length and very thin (less than 0.4 mm). Also the area that bears the 25-35 rows of hooks is very short (only the distal 2-4 %), and as the hooks are very small (15-25 |im) and transparent. There are in this collection a few which have hooks showing but most do not. If the distal end of the introvert has been torn in the collecting process, no hooks will be found. — 956 —

FIG. 6. — Golfingia misakiana. Esophagus (e) protruding through mouth ventral to tentacular crown (te). (Scanning électron micrograph 200 X •)

After prolonged considération, we have decided to name thèse G. misakiana. The opacity and color of the body wall varies with the size as does the nature of the posterior papillae. Ail of thèse have some round papillae on the trunk, concentrated at the posterior end. It is still our opinion that FiscnEii's G. hespera represent the larger, older part of this population with more opaque skin, larger papillae, and a larger number of spinelets on the hook and is, therefore, a junior synonym. A parallel situation is discussed in BERTSCH (1976) with respect to radular teeth in opisthobranch gastropods and how older taxonomic groups turn out to be little more than size catégories which are later synonomized as resear- chers collect intermediate forms.

DISTRIBUTION. — There are published records of this species from Japan, California, Peru, Brazil and Western Australia. Thèse new records from Madagascar, Mombassa, and French Polynesia suggest a circumtropical pattern.

Golfingia (Mitosiphon) trichocephala (Sluiter, 1902)

IIOE Sta. 210B ; 75 spec. ; 11/16/63 ; 21°08' N, 69°48' E ; 35 m ; Arabian Sea. —Sta. 391F ; 1 spec. (poor condition) ; 9/9/64 ; 29°26' S, 31°46' E ; 77 m ; Durban. Nosy Bé RP Sta. : 3, 2 spec. ; 5, 7 ; 8, 1 ; 9, 4 ; 11, 22 ; 13, 4. Tuléar BT Sta. : Many, mainly in the médium and fine sands on the reefs, the lagoonal bottoms and also the littoral tidal fiais with seagrass beds. — 957 —

When SLUITEH first described this species he overlooked soute important features (bilobed nephridia and four retractors), so that upon re-examinalion of the type material a redescription was called for (CUTLER, 1967 ; 1973). At that time G. tenuissima and G. longirostris (WESENBERG-LUND, 19596) were considered to be junior synonyms of this species. A lengthy discussion of the complex of related species (including G. hespera and G. misakiana) was presented. When we began working with this collection, it was thought they were ail G. tricho- cephala but when we found hooks on some, doubt began to enter and we thought we should consider them ail G. misakiana. After lengthy considération of much data it was decided to recognize two species : G. misakiana (with hooks, tentacles, and spheroid papillae on the posterior end of the trunk) and G. trichocephala (lacking hooks, tentacles, and trunk papillae). The internai anatomy, gênerai form, and size are practically identical. They are generally 3-8 mm long with introverts 8-10 times the trunk length (CUTLER, 1973, has a complète description). We believe we have seen the distal tip of the, introvert and find only small papillae. There is still the possibility that none was completely extended so tentacles could be over- looked, but we are unable to demonstrate any. The very long, thin nature of the intro- vert makes it susceptible to damage and the torn end is deceptive. It is difïicult to envision how thèse two forms coexist so closely together. We thought perhaps an examination of gut contents would demonstrate a différent food préférence (différent niche parameter) as one has tentacles and hooks, but this was not productive. We analyzed their sipunculan neighbors in the Tuléar area — with which other species do they live — but again can see no significant différences. G. trichocephala seems to be found by itself more often 122 verses 10 stations) and does not co-occur with quite as many other species (10 verses 14). They were found living at the same station 11 times (out of 87). They both occur most often with Siphonosoma cumanense and Aspidosiphon thomassini, (this latter is remarkably similar in size and shape). Whether or not earlier authors had " pure " collections or a mixture of thèse two species is uncertain. If the introvert is not completely out and one does not look very closely for the papillae, some G. misakiana could easily be overlooked and called G. tri- chocephala. It is also possible that G. tenuissima is G. misakiana in which hooks were not seen (compare figures of papillae in WESENBERG-LUND, 19596, and AMOR, 1975).

DISTRIBUTION. — Previous reports from off Indonesia, South and West Africa, and southeastern United States ail from shallow, warm water are now supplemented by thèse from Madagascar and the Arabian Sea. Unpublished records from the Gulf of Mexico, Australia, Coral and Tasman Seas, and Singapore suggest a circumtropical species.

Golfingia (Phascoloides) minuta (Keferstein, 1853)

IIOE Sta. 390S ; 59 spec. ; 9/9/64 ; 29°35' S, 31°42' E ; 138 m ; Durban.

The trunk length in this collection measures 1.5 to 12 mm and ail are 1 mm or less in diameter. The largest worm has scattered hooks measuring 25-32 [xm high. — 958 —

DISTRIBUTION. — This common Atlantic Océan species has been often recorded from cold waters in both north (up to 70° N) and, less often, south Atlantic. It also occurs in the Mediterranean, two records from the northwest Pacific, and one from Chile. One earlier record, also from the Durban area, is the only other Indian Océan record. It is interesting to speculate about its dispersai into the Pacific via a northern Arctic and sou- thern route, and into the Indian Océan via a southerly route.

Golfingia (Phascoloides) rutilofusca (Fischer, 1.916)

Golfingia sp. Stephen & Cutler, 1965 : 115. IIOE Sta. 221A ; 1 spec. ; 11/18/63 ; 22°32' N, 68°06' E ; 58 m ; Arabian Sea. NW Bombay. — 230B ; 1 spec. : 11/20/63 ; 23°31' N, 66°55' E ; 88 m ; Arabian Sea. — 391F : 7 spec. ; 9/9/64 ; 29<>26' S, 31.046' E ; 77 m ; Durban. — 391H ; 1 spec. ; 9/9/64 ; 29°21' S, 31°35' E ; 57 m ; Durban. —392K ; 7 spec. ; 9/10/64 ; 29°19' S, 31°36' E ; 38 m ; off Durban OR 391C 9/9/64 ; 29o29' S, 31o 45' E ; 86 m ; (label confusion at SOSC). — 408A ; 1 spec. ; 10/15/64 ; 16°43' S, 43°43' E ; 60 m ; NW Majunga, Madagascar. — 409 I ; 1 spee. ; 10/19/64 ; 16°03' S, 44°09' E ; 25 m ; NW Majunga, Madagascar. Nosy Bé BP Sta. : 1, 2 spec. Tuléar BT Sta. : 1)10, 1 spee. ; 1)13, 1 ; 1)29, 1 ; 1)57, 3 ; 193, 1 ; 620, 3 : 621, 3 ; 622, 14 ; 633, 2 ; 728, 2 ; 766, 1 ; 771, 2 ; 779, 6 ; 810, 2 ; 813, 1. Fréquent in sédiments (médium sands to clay) of lagoon or enclosed lagoon bottoms.

This sample of 66 worms varying in trunk length from 2-15 mm is especially important for three reasons : the information it gives us about the variable nature of the posterior end of the trunk, the first view of its unique tentacular arrangement, and the resolution of the issue of the spindle muscle raised in the literature (see STEPHEN & EDMONDS, 1972:155). FISCHEP.'S original description of this form was based on « many » spécimens from 1362 m oif Zanzibar. Ile placed it in the genus Aspidosiphon because of the shield like nature of the posterior end which lie figured (FISCHER, 1922) as very coarsely grooved with a defi- nite apex. This is now clearly seen to be dépendent ou the state of contraction/relaxation of the body wall at the time of fixation. A wide range of conditions is found from smooth and rounded to grooved and pointed (fig. 7a and 7b). The majority are more rounded than pointed. FISCHER obviously had very strongly contracted worms. FISCHER'S comments on the number of tentacles and length of introvert suggest to us he had no spécimen with completely extended introverts. In this collection the intro- verts are five to six times the trunk length and several show approximatcly 30 unique tentacles (fig. 8a and 8b). They are slender, unbranched and corne from a pad-like zone along the dorsal side of the tip of the introvert, somewhat like the « fingerprint » portion of a finger. The mouth is at the distal tip with a few tentacles around it. This arrange- ment is unlike any other known sipunculan. Hooks are absent. The coloration is rrot always a uniform red but sometimes has a blotched appearance, especially in the larger animais patches of yellowish-white are présent (fig. 9). Also, the distal hall' of the introvert gradually looses ail pigmentation. It is still a very striking worm. Internally, the two retractor muscles attach in the last fifth of the trunk and the free nephridia operi anterior to t lie anus. The gut is not formed into a tight, regular coil as l'IG. 8. Golfingia rutilofusca. Tentacular région : A, side view ; 15, dorsal view.

— 961 — in most Golfingia but is loosely coiled and tbe whole mass is free to move. The oesophagus remains attached to the retractors for a considérable distance so when the introvert is extended, the front end of the coil is near the anterior end of the trunk. However, when the retractor muscles are contracted, this région of the gut coil is pulled back to almost the posterior end of the trunk. No évidence of a spindle muscle is présent. A well defined wing muscle anchors the anal région of the rectum to the body wall.

DISTRIBUTION. — The three carlier records of this species corne from Durban, Mozam- bique, and Zanzibar at depths from 57-1562 m. This is the first from Madagascar or India and the first from such shallow water.

Golfingia (Phascoloides) sp.

IIOE Sta. JR 38-10 ; 6 spec. ; 1/20/64 ; 13°24' S, 48°18' E ; 1 m ; Nosy Bé, stones and mud. — JR 33-15 ; 3 spec. ; 1/15/64 ; 13°26' S, 48°23' E ; 1 m ; Nosy Bé, under intertidal rocks. Tuléar BT Sta. : 843B, 1 spec.

Ail of thèse spécimens are less than 5 mm long and probably juvénile forms of some member of this subgenus. It is tempting to assign a name to them, but they are simply too nondiscript for us to do so. They are similar to both G. minuta and G. pellucida in many ways.

Phascolion beklemischevi Murina, 1964

IIOE Sta. 371F ; 2 spec. ; 8/18/64 ; 24°46' S, 35°18' E ; 110 m ; off southern Mozambique.

Thèse are small, transparent worms lacking holdfasts but bearing round, flat papillae. The sharp hooks are strongly lient and in the smallcst one (trunk plus introvert measures 2 mm), the trunk was about twice the length of the introvert. The larger one (5 mm) had been taken from a gastropod shell. The two retractor muscles originate from very near the posterior end.

DISTRIBUTION. — The only other record of this form is the original description from the southern Mediterranean Sea so this is a signifîcant extension of its known range.

Phascolion megaethi n. sp.

Tuléar BT Sta. : 64, 2 spec. ; 788, 1 ; 790, 1 ; 801, 2 ; 803, 2. More frequently in the sédiments elog- ging the outer boulder tract ; accidently in a sand dune of the reef inner slope in the lagoon.

Thèse eight worms from five stations range in size from 4-12 mm. Most are from gastropod shells. The trunk is pale and smooth with large, dark red-brown, mammi- form papillae (100-150 (xm in height) around the anterior end of the trunk which at first — 962 —

FIG. 10. — Phascolion megaeihi n. sp. : A, external view (scale = 1 mm) ; B, anterior end of trunk. •­ 96 3 —

FIG. 11­12 . — Phascolion megaethi n . sp . : II, lioldfasts o n posterio r li p o f trun k (scal e = 0. 5 mm) ; 12, retrac­ tor origin s nea r posterio r lip . D R — dorsa l retracto r ; VN C = ventra l nerv e cor d ; V R = = ventra l retractor. glance resemble s a n Aspidosipkon sliiel d (fig . 10) . fIoldfast s ar e fe w an d small , singl e pointed , triangular structure s restricte d t o th e posterio r en d o f th e trun k (fig . 11) . O n on e larg e spécimen the y ar e arrange d i n tw o row s aroun d th e narrowe d posterio r tip , i n other s the y are scattered . Th e introver t bear s few , scattered , short , blun t hook s (30­3 5 p i n height) . There ar e fewe r tha n 1 5 tentacle s présent . Internally th e tw o retracto r muscle s originat e nea r on e another , eac h fro m a singl e root, bu t i n a n unusua l fashion . Th e ventra l muscl e i s abou t on e hal f th e diamete r o f th e dorsal an d originate s slightl y behin d th e dorsa l (fig . 12) . Th e intestin e ha s th e normal , loose Phascolion loop s an d n o apparen t coils . There ar e severa l specie s i n thi s genu s wit h tw o retractors , adhesiv e papilla e an d hooks . — 964 —

P. heteropapillosum i s simila r externall y bu t th e fewe r numbe r o f tentacles , darke r papilla e at th e anterio r en d o f the trunk , th e holdfast s wit h a singl e tooth , an d th e nature o f retracto r muscle origin s set s thi s specie s apart . Th e nam e refer s t o th e larg e red­brow n natur e o f the papilla e aroun d th e anterio r en d o f th e trunk .

The typ e materia l ha s bee n deposite d i n th e Muséu m nationa l d'Histoir e naturelle , Paris . Holotype : Cat . n ° AH­41 2 ; BT Sta . 78 8 ; " Gran d Récif" , Tuléar . Paratyp e : Cat . n » AH­41 3 ; BT Sta . 79 0 ; " Gran d Réci f " , Tuléar .

Phascolion pharetratum Sluiter , 190 2

Tuléar B T Sta . : 228 , 1 spec . ; 240 , 3 ; 654B , 1 ; 741 , 1 ; 843 , 2 . I n coars e sédiment s o f th e ree f front.

Thčse animai s wer e take n fro m gastropo d shell s an d belon g t o thi s uncommo n specie s on th e basi s o f thei r peculiar , numerous , large , bent , dull , dar k brow n hook s an d absenc e of holdfasts . A t th e bas e o f th e introver t o f on e spécime n i s a thic k colon y o f entoprocts . There ar e als o colorles s mammifor m papilla e aroun d th e introver t bas e an d filamentous tentacles ar e visibl e o n th e wor m fro m Sta . 228 . Th e midtrun k régio n i s smooth an d almos t transparent. Th e tw o retracto r muscle s o f unequa l siz e originat e wel l i n fron t o f th e poste ­ rior end .

DISTRIBUTION. — Thčs e record s ar e th e firs t sinc e it s origina l descriptio n fro m th e other sid e o f thi s océa n of f Malaya .

Phascolion strombi africanum (Fischer , 1923 )

Phascolion africanum Fischer , 192 3 : 5 ; WESENBERG­LUND , 196 3 : 134­135 . Tuléar B T Sta . : Al, 1 spec . ; 62 , 2 ; 63 , 4 ; 91 , 1 ; 630 , 1 ; 737 , 1 ; 889 , 1 ; 906 , 1 . I n médiu m and fine sand s o f san d bank s o n ree f o r o f th e lagoo n (inne r ree f slope , lagoona l bottoms) .

Phascolion africanum (Fischer , 1923 ) wa s describe d fro m a singl e spécimen . Th e onl y other repor t wa s WESENBERG­LUN D (1963 ) fro m thre e damage d spécimens . Thčs e 1 2 animai s give évidenc e whic h strongl y suggest s th e wisdo m o f reducin g thi s taxo n t o subspecie s rank a s th e différence s fro m P. strombi ar e ver y slight . I t seem s logica l t o conside r thi s a geographicall y isolate d populatio n whic h ha s deviate d somewha t fro m th e mai n stock . The distinctio n mad e i n STEPHE N & EDMOND S (1972 ) center s o n P. strombi's hold ­ fasts havin g on e o r mor e teet h whil e P. africanum supposedl y lack s thčs e point s o n th e holdfasts. Whil e i t i s tru e tha t mos t ar e semicircula r o r U­shaped , a fe w d o hav e distinc t points o r teet h o n them . Th e smalles t animai s (abou t 2­ 3 mm ) hav e papilla e whic h hav e not ye t develope d th e chitinize d rim s o r borders . I t seem s éviden t fro m othe r collection s also, tha t th e natur e o f thčs e papilla e varie s accordin g t o âg e an d microhabitat . HYLLE ­ BERG­KIRSTENSEN (1975 ) ha s als o suggeste d tha t the y ma y no t be , i n fact , attachmen t papillae (holdfasts ) bu t rathe r serv e a n interna i housekeeping/cleanin g function . — 96 5 —

The hook s measur e 50­7 0 u. m hig h an d ther e ar e abou t 4 0 tentacle s o n th e large r worms. Th e tw o retracto r muscle s originat e nea r th e posterio r end , th e thinne r ventra l one bein g a littl e behin d th e large r dorsa l muscle . I n th e on e fro m Sta . 889 , ther e i s a tendency fo r th e longitudina l muscle s t o divid e int o separat e band s a t th e anterio r en d o f the trun k a s i s sometime s note d i n large r Aspidosiphon (Aspidosiphon).

DISTRIBUTION. — Th e previou s record s o f thi s for m corn e fro m of f Cap e Province , South Africa , s o thi s constitute s a sligh t extensio n o f it s range .

Phascolion valdivae Fischer , 191 6

IIOE Sta . 390 S ; 1 3 spec . ; 9/9/6 4 ; 29°35 ' S , 31°42 ' E ; 13 8 m ; of f Durban .

Thčse worms , whos e siz e rang e i s 7­2 5 mm , fit FISCHER' S descriptio n fairl y well . Th e tall, slender , spinelik e hook s measur e 80­9 5 pm . Ther e ar e tw o introvert s i n th e sample , unattached t o an y trunk , whic h looke d simila r bu t th e hook s o n thčs e wer e onl y 50­7 0 [i.m high. The y ma y hav e com e fro m smalle r worms . Thčs e animai s wer e thin­walled , semi ­ transparent, an d cam e fro m scaphopo d shells . On e ha d a commensa l polychaet e wit h it . The intestin e i s no t loosel y loope d a s i n man y Phascolion bu t i s i n a wel l define d coil . The holdfast s d o no t hav e a pigmente d chitinou s ri m bu t ar e circular/ova l an d flat , som e having a clear , thickene d border . Th e nephridiu m i s shor t an d attache d fo r mos t o f it s length, no t fre e a s FISCHE R notes . Th e singl e retracto r muscl e ha s a broa d origi n whic h is bifurcated .

DISTRIBUTION. — Th e sol e othe r repor t o f thi s specie s corne s fro m St . Paul' s Islan d from a scaphopo d shel l a t 15 8 m , s o thi s specie s seem s t o b e a souther n India n Océa n for m so far .

Phascolion n . sp .

IIOE Sta . JR­ 2 ; 1 spécime n fro m gastropo d shel l ; 12/28/6 3 ; 13°26 ' N , 48°23 ' E ; 1 m ; Nos y Bé , Madagascar.

This singl e spécime n ha s a trun k measurin g abou t 1 5 X 5 m m an d th e introver t i s completely retracted . Th e epidermi s i s semi­transparen t an d colorles s excep t fo r th e ante ­ rior quarte r wher e i t become s thicker , mor e heavil y papillated , opaque , and white . Larg e papillae ar e présen t an d mor e concentrate d anteriorly , bu t chitinize d holdfast s (adhesiv e or attachmen t papillae ) ar e lacking . Als o lackin g ar e introver t hooks , bu t norma l ten ­ tacles ar e présent . Internally th e gu t i s throw n int o loop s bu t n o coils , fixing muscle s hol d thi s i n place . The nephridiu m i s abou t 1/ 3 th e trun k length , fragile , an d partiall y attached , openin g posterior t o th e anus . Th e dorsa l retracto r muscl e originate s a t th e lef t sid e o f th e ventra l nerve cor d anterio r t o it s termination , an d fro m thre e roots . Th e ventra l i s 1/ 5 t o 1/ 6 the siz e o f th e dorsa l an d originate s 2 m m posterio r t o th e origi n o f th e dorsal . — 966 —

In thi s genu s ther e ar e onl y thre e specie s (P. botulum, P. artificiosum, an d P. sand- vichï) wit h tw o retractor s an d hook s absent , bu t ai l o f thčs e hav e adhesiv e papilla e whic h this for m lacks , makin g i t distinct . Thi s i s lef t unname d i n keepin g wit h ou r philosoph y that specie s ar e population s an d i t i s necessar y t o hav e mor e tha n a singl e spécime n t o produce a meaningfu l ne w specie s description .

Themiste lagenformis Baird , 186 8

IIOE Sta . J R 13­1 ; 1 6 spec; 12/26/63 ; 13°24 ' S , 48°19 ' E ; 1 m; Nos y B é ; i n har d cla y an d rock. Fort­Dauphin, DECAR Y coll. , 1932 , 2 spec .

Within thi s genu s thčs e 1 8 worm s wit h tw o retracto r muscle s an d shor t vill i belon g to Grou p 2 (STEPHE N & EDMONDS , 197 2 : 194) . Havin g n o hook s an d shor t branchin g villi the y ar e ver y simila r t o T. robertsoni. Th e mai n distinctio n seem s t o b e th e numbe r of tentacula r stem s an d whethe r ther e ar e fou r o r six . Howcver , whe n th e introver t i s retracted, thi s i s ver y difficul t t o precisel y ascertain . Also , th e literatur e i s no t consistan t and a s STEPHE N & EDMOND S (197 2 : 205 ) poin t ou t : " Th e specie s i s no t alway s eas y t o identify " . The y the n elaborat e furthe r o n th e problems . I n RIC. E é V STEPHEN (1970 ) where the y redescrib e T. hennahi, i t i s pointe d ou t tha t thre e specialist s lookin g a t th e saine wor m sa w four , five , an d si x mai n stems . Thi s identificatio n i s mad e wit h som e réservation. Thčse spécimen s rang e i n trun k lengt h fro m 4­1 5 mm . Th e nephridi a whic h ar e a s long a s th e trun k ope n a li t tic posterio r t o th e anus . Th e tw o retracto r muscle s originat e in th e posterio r fifth o f th e trunk .

DISTRIBUTION. — Themiste lagenformis (previousl y T. signifer) ha s bee n reporte d many time s fro m th e Indo­Wes t Pacifi c are a includin g Madagascar . Singl e record s fro m Argentina an d Wes t Afric a ar e th e onl y one s fro m outsid e thi s area .

Themiste lissa (Fisbcr , 1952 )

IIOE Sta . 357 B ; 2 spec . ; 7/29/6 4 ; 29°11' S , 32°02 ' E ; 6 8 m ; Durban .

Thčse tw o completel y retracte d ta n spécimens , 1 1 an d 1 2 m m long , difîe r fro m th e other herei n reporte d member s o f thi s genu s b y havin g long , thi n tubule s comin g of f th e contractile vessel . The y hav e tw o relracl.o r muscles , lac k hooks . an d thre e lixin g muscle s are présent . Th e anu s i s anterio r t o th e nephridiopores . I n STEPHE N & EDMOND S (197 2 : 194) ther e ar e si x specie s i n Group s 3 and 4 that ar e ver y simila r (se e als o RIC. E él ­ STEPHEN , 1970 : 3 6 wher e the y com e t o a simila r conclusion) . Fou r o f thčs e wer e describe d b y W. K . FISHE R an d fiv e cam e fro m th e Californi a coas t whil e th e sixt h i s reporte d fro m Peru an d Chile . T. lissa an d T. schmittii ar e separate d fro m th e other s becaus c thei r nephridiopores ar e posterio r t o th e amis , a characte r whos e constanc y i s ope n t o som e question. Fo r example , whe n RIC E & STEPHE N (197 0 : 35 ) redescribe d T. hennahi, on e — 96 7 ­ of th e othe r four , the y sai d " nephridiopore s ope n slightl y posteriorl y t o th e anus" , no t anterior a s i n STEPHE N & KDMOND S (1972) . Th e allege d différence s betwee n thčs e specie s arc subtle , bu t w e wil l no t dea l wit h tha t issu e herein .

DISTRIBUTION. — Thi s i s th e first repor t o f thi s specie s sinc e it s origina l descriptio n from th e intertida l zon e o f souther n California , a rathe r strikin g extensio n o f it s range .

Themiste minor (Ikeda , 1904 )

IIOE Sta . 3701 1 ; 1 spec . ; 8/18/6 4 : 24°40 ' S , 35°28 ' E : 34 7 m : Mozambique Channel .

This single , smal l spécime n ( 5 m m trunk ) ha s a whitis h trun k wit h brow n pigmen t towards th e anterio r en d wher e i t i s als o hostin g a colon y o f endoprocts . Th e introver t is withdrawn bu t hook s ar e présen t measurin g 50­6 0 u. m i n height . Internally ther e ar e tw o retracto r muscles , th e nephridi a ope n slightl y anterio r t o th e anus, an d ther e ar c short , unbranche d contractil e vesse l villi . According t o STEPHE N C V EDMONIJS' (197 2 : 194 ) scheme , thi s worm belong s t o Grou p 2 and withi n thi s grou p i s simila r t o T. lagenformis an d T. huttoni. T. lagenformis i s sai d to lac k hook s an d T. huttoni ha s branche d contractil e vesse l villi . Thi s latte r distinctio n is troublesom e a s i t woul d appea r possibl e fo r a youn g T. huttoni t o produc e vill i whic h begin a s unbranche d structures , onl y later , a s the y increas e i n siz e t o bifurcate . Thi s ha s been note d i n Golfingia caiharinae (Cutler , 1973) . Th e smal l siz e o f thi s wor m make s it suspect , bu t thi s taxo n seem s mos t logica l fo r now .

DISTRIBUTION. — Previou s record s o f this specie s corn e from China , Japan , .\e w Zealand , and th e Tasma n Se a the n ski p acros s th e India n Océa n t o Sout h an d Sout h Wes t Africa . This spécime n reinforce s it s présenc e i n thi s corne r o f thi s océan .

Themiste robertsoni (Stephe n c V Robertson , 1952 )

IIOE Sta . T e Veg a 7 2 I.I I 4 : 1 spec ; 10/19/63 ; 01°16 ' N , 103°48 ' E ; 1 m ; Singapor e beach . ­ India , N o f Oka n Poin t : 2 spe c 3/9/6 3 ; 22°30 ' N , 09°04 ' E ; 1 m . — JR­24 A ; 1 spec . ; 1/4/64 ; 13024 ' S . 48°17 ' E : 1 m ; Nos y B é ; mud fiât . — J R 38­ 1 ; 9 spec . ; 1/20/6 4 ; 13o24 ' S , 48°18' E ; 1 m ; Nos y B e ; roc k an d l'oral .

Tuléar, coll . LEGENDRE , 1964 , 8 spec .

Thčse 2 1 worm s rangin g i n siz e fro m 4­3 0 m m ar e als o i n STEPHE N & EDMONDS ' Group 2 (1972 : 194) . Th e absenc e o f hooks , th e blu e are a toward s th e introver t tip , an d tentacular arrangemen t hel p plac e the m i n thi s taxon whic h i s very simila r t o T. lagenformis. The introver t i s les s tha n hal f th e trun k lengt h an d numerou s shor t vill i ca n b e seen . Th e anus an d nephridiopore s ar e a t nearl y th e sam e level . Thi s grou p doe s loo k différen t tha n those we'v e calle d T. lagenformis, bu t sometime s th e décision s ar e uncomfortabl y subjec ­ tive. I t i s hope d tha t som e revisionar y wor k i n thi s genu s wil l b e fortheomin g soon . — 90 8 —

DISTRIBUTION. — Thi s specie s ha s bee n know n fro m onl y Zanziba r an d Sout h Africa , so thčs e record s fro m Madagascar , India , an d Singapor e ar c a majo r northerl y an d easterl y extension o f it s know n rang e makin g i t a membe r o f th e Indo­Wes t Pacifi c shallo w wate r fauna.

Aspidosiphon (Aspidosiphon) zinni Cutler , 196 7

IIOE Sta . 371 E ; 5 spec . ; 8/19/64 ; 24°46' S , 35°20 ' E ; 13 2 m ; Mozambique Channel .

Ail o f thčs e smal l (3­ 5 mm) , slende r an d transparen t worm s ha d thei r introvert s with ­ drawn bu t small , scattered , single­pointe d hook s coul d b e foun d an d i n othe r way s the y match thi s species . Thei r gęnera i shap e an d siz e i s simila r t o Golfingia minuta, bu t th e " fla t " anterio r en d wit h it s granula r ana l shiel d i s distinctive .

DISTRIBUTION. — Th e onl y othe r publishe d record s o f thi s specie s ar e o n th e conti ­ nental slop e an d ris e of f th e Atlanti c coas t o f th e Unite d State s an d Bermud a betwee n 1 100­ 3 00 0 m . Ther e ar e unpublishe d record s fro m elsewher e i n th e Atlanti c Océa n (nort h and south ) bu t thčs e ar e th e firs t recor d fo r th e India n Océan .

Aspidosiphon (Aspidosiphon) elegans (Chamiss o & Eysenhardt , 1821 )

IIOE Sta . H A 3 9 ; 2 spec . ; 1/12/6 4 ; 27°16 ' N , 33°47 ' E ; 2 m ; Re d Sea . — H A 67­4 0 ; 3 spec . ; 7/10/67 ; 7°21 ' S , 72°28 ' E ; 1 m ; Dieg o Garcia . — B­ 3 ; 1 spec . ; 2/9/6 3 ; 12°00 ' S , 96°50 ' E ; 1 m ; Cocos­Keelin g Islands , reef . New Hébrides , Sta . 98 8 ; 9 spec . coll . D E GAILLANDE .

Thčse fiftee n spécimen s wer e easil y referabl e t o thi s species , wit h thei r larg e spine s covering mos t o f th e introver t proxima l t o th e hooke d région . Thčs e dar k brow n spine s show considérabl e variatio n i n number , size , an d densit y alon g th e introver t whic h showe d an interestin g coorelatio n wit h hoo k sharpness . Thos e spécimen s wit h sharpl y pointe d hooks hav e a dens e populatio n o f spine s wherea s whe n fewe r spine s ar e présent , th e hook s have a dulle r apex . I n addition , o n an y singl e worm , th e large r spine s wer e foun d o n th e dorsal sid e o f th e introver t an d thčs e wer e als o mor e sharpl y ben t toward s th e posterio r en d of th e organism . Thos e o n th e ventra l sid e ten d t o b e smalle r an d les s bent . I t wa s also observe d tha t th e smalle r th e spine , th e straighte r i t was . I n th e res t o f thei r morpho ­ logy, thčs e spécimen s nicel y matc h th e descriptio n give n i n STEPHE N & EDMOND S (197 2 : 235). Th e trun k lengt h range s fro m 10­5 8 mm. Th e siz e o f th e dar k platelet s o n th e ana l shield i s quit e variable .

DISTRIBUTION. — Thi s specie s ha s bee n foun d fro m th e Re d Se a dow n th e coas t o f East Afric a t o Mozambiqu e an d Mauritius . I t the n occur s i n Malaya , Japan , an d severa l West Pacifi e Islands . A singl e repor t fro m Florid a o f a single , dessicate d spécime n (WESEN ­ BERG­EUND, 1954 ) doe s no t fit thi s apparentl y Indo­Wes t Pacifi c shallo w wate r for m herein reporte d fo r th e first tim e fro m th e centra l an d easter n India n Océan . — 96 9 —

Aspidosiphon (Aspidosiphon) exhaustus Sluiter , 191 2

IIOE Sta . 206 A ; 2 spec . ; 11/15/6 3 ; 20°21 ' N , 69°58 ' E ; 7 5 m ; Arabia n Sea , N W Bombay . — 358A ; 5 spec . ; 7/30/6 1 ; 29°19 ' S , 32°00 ' E ; 36 6 m ; Durban . — 370 H ; 3 spec . ; 8/18/6 4 ; 24°40' S , 35°28' E ; 347 m ; Mozambique Channel . — 390 E ; 2 spec. ; 9/8/64 ; 29°42' S , 31°38' E ; 350 m ; Durban . — 408 D ; 1 spec . ; 10/15/6 4 ; 16°42 ' S , 43°19 ' E ; 22 5 m ; N W o f Majunga , Madagascar. Tuléar B T Sta . 62 , 4 spec .

Thčse 1 7 spécimen s wit h singl e pointe d hook s (varyin g i n siz e fro m 1 3 [x m i n a 2 m m worm t o 3 5 p m i n a 2 8 m m worm) , followe d b y a régio n o f straigh t spines , ar e referabl e to thi s species . Th e ana l shiel d i s médiu m t o dar k brown , wit h wel l define d margins , shor t grooves dorsall y an d granula r régio n ventrally . Th e cauda l shiel d i s les s pigmente d bu t usually wel l define d an d bear s abou t 20­2 5 radiatin g grooves . The introver t i s longe r tha n th e trunk . Th e nephridi a ope n a t th e leve l o f th e anus , are attache d fro m 50­10 0 % o f thei r length , an d th e spindl e muscl e i s attache d posteriorly . The retracto r muscl e appear s a s a singl e muscl e wit h tw o roots , o r a s tw o muscle s whic h fuse. On e wor m fro m Sta . 206 A ha s a retracto r muscl e whic h i s a singl e muscl e nea r it s insertion a t th e head , the n divide s int o two , bu t fuse s int o on e again , the n split s int o tw o roots wher e i t originate s a t th e posterio r end . GIDB S (1973 ) discusse d a relate d cas e o f splitting an d fusin g i n détai l fo r Golfingia rimicola. A recta l caecu m i s présent . Most o f thčs e cam e fro m scaphopo d shell s bu t thos e fro m Sta . 6 2 wer e livin g i n gastro ­ pod shells . On e fro m 208 A ha s a smsl l commensa l bivalv e mollus c attache d b y byssa l threads t o it s posterio r end . Th e thre e worm s fro m Sta . 370 H ar e les s tha n 2 m m lon g but see m t o fi t int o thi s grou p wit h som e réservations . Th e Tuléa r worm s (Sta . 62 ) als o differ fro m th e res t (gastropo d shells , shallo w depth , ana l shiel d différences ) an d ma y repre ­ sent a subspecie s o r a n ccologica l variet y ; i t i s als o place d her e wit h som e réservations .

DISTRIBUTION. — Thčs e record s ar e a valuabl e additio n t o a rathe r peculia r pattern . There ar e tw o report s fro m northwester n Afric a (Cong o an d Morocco) , on e fro m sout h eastern Australia , on e fro m th e Gul f o f Tonkin / Indo­China , an d on e fro m Isl e d e Paocu a in the souther n Pacifi c Océan . Thčs e bein g the firs t fro m th e wester n India n Océa n suggest s the possibilit y o f a widesprea d deepe r wate r (approximatel y 50­75 0 m ) membe r o f thi s genus whic h i s absen t fro m eithe r sid e o f th e Americas .

Aspidosiphon (Aspidosiphon) jukesii Baird , 187 3

IIOE Sta . J B 22­ 5 ; 1 spee . ; 1/2/6 4 ; 13°24 ' S , 48°13 ' E ; 1 m ; Nos y B é ; volcani c rock . — J R 32­10 ; 2 spec. ; 1/14/6 4 ; 13°34 ' S , 48°18 ' E ; 1 m ; Nosy B é ; mud/sand an d rock . — J R 33­ 2 ; 1 spec. ; 1/15/64 ; 13°26' S , 48°23' E ; 1 m ; Nosy B é ; dead coral . — J R 38­ 1 ; 11 spec. ; 1/20/64 ; 13°24' S , 48°18 ' E ; 1 m ; Nos y B é ; roc k an d coral . — 270 A ; 1 spec . ; 12/4/6 3 ; 22°07 ' N , 59°48' E ; 56 m ; Gul f o f Oman . — 371 F ; 1 spec. ; 8/18/64 ; 24°46' S , 35°18 ' E ; 11 0 m ; Sout h Mozambique. — 372 L ; 1 1 spec . ; 8/19/64 ; 25°07' S , 34°34 ' E ; 11 2 m ; South Mozambique . — 372M ; 2 spec . ; 8/19/6 4 ; 25°03 ' S , 34°31 ' E ; 5 5 m ; Sout h Mozambique . — 372 P ; 5 spec . ; 8/24/64 ; 25°57 ' S , 33°02 ' E ; 3 7 m ; Sout h Mozambique . — 372 Q ; 2 spec . ; 8/22/64 ; 25°57' S ,

1, 9 — 970 —

33°02' E ; 4 2 m ; South Mozambique . — 390 S ; 226 spec . ; 9/9/64 ; 29°35' S , 31°42 ' E ; 13 8 m ; Durban. Nosy B é R P Sta . 6 , 1 spec . Tuléar B T Sta . : Many, fre e i n gastropo d shell s o r associate d wit h fre e livin g coral s (Heleropsammia michelini, Heterocyathus aequicostatus) aliv e o r dead . I n sédiment s fro m coars c sand s t o ver y fine sand s generally . Moorea B T Sta . 32 , 1 spec .

Many o f thčs e 50 3 spécimen s ha d inhabite d gastropo d shell s an d solitar y coral s whil e alive an d therefore , accurat e measurement s wer e impossibl e t o obtain , bu t th e larges t worms ar e betwee n 1 5 an d 2 0 mm , ver y fe w ove r 1 0 mm , man y aroun d 5 mm , an d a fe w about 1.5­ 2 mm . Thei r interna i anatorn y closel y fit tha t presente d i n STEPHE N & EDMOND S (1972 : 228) . O f parlicula r interes t i s a statemen t the y mak e whic h support s m y argumen t for no t usin g th e conditio n o f th e longitudina l musculatur e a s a generi c characte r : " Longi ­ tudinal muscle s continuon s excep t anteriorl y wher e the y ten d t o split . On th e sam e pag e the y stat e : " .. . carrie s abou t 4 0 row s o f single­pointe d hook s and thei r ke y t o thi s taxo n i s similarl y constructed . However , i n HIC E & STEPIIEN' S (1970) redescriptio n o f th e typ e (wherei n the y submerge d th e bette r know n junio r synony m of A. coraUivola Sluiter ) the y sa y th e hoo k ha s a " secondar y termina l poin t " a s hav e othe r authors. CUTLE R (1965 ) note s : " Th e secondar y toot h o n th e hoo k i s quit e variabl e i n size bu t usuall y présen t " . Afte r examinin g man y hook s fro m différen t size d worms , w e propose th e followin g : A secondar y poin t o n th e hoo k i s analogou s t o a gre y hair . I l usually dcvclop s onl y i n matur e individual s an d a t différen t âge s (som e prematurely , others ver y late) , bu t i t i s not présen t i n youn g forms . Th e timin g an d degre e o f expressio n is variabl e bu t âg e (size ) relate d an d no t uniforml y présen t withi n a larg e populatio n mad e up o f différen t âge s an d races . A secon d se t o f observations , o n th e natur e o f th e ana l shield , le d t o th e followin g conclusions : Th e appearanc e o f thi s structur e change s wit h âg e also . W e hav e identi ­ fied thre e " stage s " i n thi s séquence . Stag e 1 — distinc t longitudina l groove s dorsall y and a ventra l are a o f spine­lik e processes . Stag e 2 — th e longitudina l groove s becom e more restricte d t o th e dorsa l margin , ther e i s a centra l régio n o f irregula r rectangle s wit h oecasional suggestion s o f transvers e ridge s an d grooves , an d a narro w ventra l zon e o f spines. Stag e 3 — onl y remnant s o f groove s o n th e dorsa l edge , a narro w stri p o f spine s ventrally, an d mos t o f th e surfac e covere d wit h granule s o r rectangles . Thčs e ar e genera ­ lizations, bu t a s suc h hol d tru c mos t o f th e time . Th e ide a tha t thčs e ar e fixed an d unchan ­ ging structure s i s fallacious .

DISTRIBUTION. — Thčs e records , togethe r wit h earlie r one s fro m Madagascar , Zanzibar , Gulf o f Manaar , Ceylon , an d Malay a suppor t it s membersbi p i n th e India n Océa n shallo w water fauna . f t i s th e secon d mos t commo n specie s i n thčs e collections .

Aspidosiphon (Aspidosiphon) kovaleskii Murina , 196 4

IIOE Sta . 391 J ; 3 spec . ; 9/9/64 ; 29°21' S , 31°35 ' E ; 5 7 m ; Durban . — 392 K ; 4 spec . ; 9/10/64 ; 29°19' S , 31°26 ' E ; 3 8 m ; Durban . — 394 B ; 1 spec . ; 9/25/6 4 ; 29°27 ' S , 31°31 ' E ; ' 7 0 m ; Durban. — 45 3 ; 5 spec . ; 12/17/6 4 ; 11°11 ' N , 51°14 ' E ; 4 8 m ; Somalia­Gul f o f Aden . — 97 1

11' ­ 1 3 spécimen s rang e i n siz e fro m 3­1 8 mm . Th e introver t carrie s scattered , single­pointed hook s abou t 20­2 5 u. m tall . Th e ana l shiel d i s groove d an d ha s spine s alon g the ventra l margin . However , i n th e smalle r (3­ 4 mm ) spécimen s thi s sam e are a ha s granular unit s whic h evidentl y continu e t o gro w an d becom e spine­lik e structures . Th e borders ar e quit e distinct . Intcrnall y th e gu t i s attaehe d posteriorl y b y a spindl e muscle . The tw o root s o f th e retracto r muscl e hav e thei r origin s fro m th e posterio r en d o f th e trun k and th e nephridiopore s ope n a t th e sam e leve l a s th e anus . A t leas t on e o f th e spécimen s was inhabitin g a n empt y scaphopo d shel l a s wer e th e holotypes .

DISTRIBUTION. — Previou s record s o f thi s specie s ar e fro m th e Agean , Adriati c an d Re d Seas an d th e Gul f o f Aden . Thčs e spécimen s fro m th e wester n edg e o f th e India n Océa n are a majo r southerl y expansio n o f thi s range .

Aspidosiphon (Aspidosiphonl venabulus Sclenka , d e Ma n & Bulow , 188 3

Tuléar B T Sta . : 1)1 , 2 spec . ; 1)2 , 2 ; 1)9 , 4 ; 3(15 , 4 ; 1106 , 1 ; 652 , 1 ; 813, 3 . I n ver y fin e sand s and silts , mor e frequentl y i n lagoona l bottoms .

Thčse 1 7 spécimen s lackin g hooks , wit h a singl e retracto r muscle , an d a dar k ana l shield ar e easil y referabl c t o thi s species . Th e ana l shiel d i s granula r i n som e an d coarse r in others wit h redueed spine s o r large , pointed, wart­lik e unit s o n th e edg e an d wit h a groove d appearanee i n most . Th e nephridi a ar e abou t a s lon g a s th e trunk , attaehe d fo r 2/ 3 thei r length, an d ope n posterio r t o th e anus . A singl e (ixin g muscl e i s présen t an d th e spindl e muscle i s attaehe d posteriorly . Th e tw o root s o f th e retracto r muscl e originat e a t th e posterior en d o f th e trunk . Thčs e spécimen s ar e betwee n 5 an d 1 5 m m long , som e fro m gastropods an d other s wer e no t coiled , havin g inhabite d som e othe r shelter .

DISTRIBUTION. — Ai l five o f th e previou s record s o f thi s specie s ar e fro m Wes t Africa n waters. Thčs e Madagasca r worm s ar e the n th e first recor d fro m th e India n Océan .

Aspidosiphon (Aspidosiphon) thomassini n . sp .

IIOE Sta . H A 67­4 0 ; 1 spec. ; 7/10/67 ; 7°21' S , 72°28 ' E ; 1 m ; Dieg o Garcia . Nosy B é B T Sta . : 553 , 1 spec . ; 554 , 1 ; 556 , 1 . Enhalus acoroides seagras s beds . Tuléar B T Sta . : 19 6 spécimen s collecte d i n 5 3 stations , mos t frequentl y i n th e médiu m sand s an d fine sand s wit h n o mor e 1 0 % o f silt , an d mor e eommonl y o n th e botto m o f th e ree f pools , in th e seagras s bed s an d th e bottom s o f enclose d lagoon s an d o f th e lagoon , i n th e ree f area , but als o i n th e terrigenou s littora l seagras s beds . Moorea B T Sta . : 19 , 6 spec . ; 27, 2 0 ; 29, 13 .

One o f th e mor e distinguishin g characteristic s o f thi s specie s i s tha t th e introver t is no t a t th e typica l 9 0 degre e angl e fro m th e trun k bu t rathe r corne s of f a t les s tha n 6 0 degrees, usuall y a t 40­4 5 degrees , fro m th e mai n axi s o f th e trunk . Thi s introver t i s fro m 2­4 time s th e trun k length . Th e trun k lengt h varie s i n thi s populatio n fro m 1.5­ 7 m m FIG. 13 . — Aspidosiphon thomassini n . sp . Wliol o animal . (Scal c = 1 mm. ) — 973 — and i n diamete r fro m a littl e les s than 1 mm t o 3 mm whil e th e introver t diamete r measure s 0.5­1 m m (fig . 13) . Th e colo r o f th e preserve d materia l range s fro m a reddis h brow n t o an off­white , mos t bein g a ligh t reddis h tan . N o worm s i n thi s collectio n hav e thei r intro ­ verts completel y extende d s o th e natur e o f th e tentacle s canno t b e commente d on . Hook s were no t observed . The ana l shiel d i s ofte n poorl y define d an d quit e variabl e (fig . 13 , 14) . I n thos e wher e it i s wel l developed , th e chitinoi d plate s ar e randoml y place d an d lo w i n profile , sometime s gathered int o longitudina l an d possibl y i n transvers e row s formin g lo w ridge s wit h inter ­ vening furrows . Th e averag e diamete r o f th e platelet s decrease s toward s th e edg e o f th e shield. Th e posterio r dorsa l margi n i s distinc t often , bu t no t outstanding . A t th e othe r end o f th e variatio n ar e shield s mad e u p o f onl y a fe w scattere d platelet s disburse d i n a rough, slightl y groove d epidermi s wit h n o clea r borders . Mos t animai s exhibi t somethin g intermediate t o thčs e tw o extręmes . Th e cauda l en d o f th e anima l i s essentiall y withou t a shiel d bu t ma y sho w a ringe d appearanc e an d b e somewha t mor e roug h o r rugose . I n a fe w large r individual s a vagu e suggestio n o f radiatin g groove s i s apparent . N o ski n papillae ar e visible , but scattere d flattene d ski n gland s (a s i n Siphonosoma) ma y b e présent . The trun k surfac e i s gcnerall y smooth , bu t unde r magnificatio n ofte n ha s a reticulat e surface wit h fain t annula r an d longitudina l groove s givin g a vagu e Sipunculus-\ikc appea ­ rance. Thi s conditio n i s mor e obviou s i n th e darke r colore d individual s an d ma y b e du e to a préservatio n technk|ue . Internally th e singlc­lobe d nephridi a ar e attache d fo r almos t thei r entir e lengt h an d open slightl y posterio r t o th e anus . Thčs e ar e abou t 1/ 2 th e trun k lengt h an d th e attach ­ ment membran e connectiv e tissu e ma y no t b e continuou s alon g it s entir e length , bu t rathe r may b e attache d a t intervai s alon g th e way . A singl e fixing muscl e nea r th e junctio n o f the intestin e an d rectu m ma y b c prescrit , an d th e spindl e muscl e i s attache d posteriorly . The rectu m ha s a diameter tha t i s les s than th e intestin e an d lack s a caecum . Th e retracto r muscle corne s fro m tw o origins , probabl y bes t describe d a s a singl e retracto r wit h tw o roots althoug h i t coul d b e interprete d a s tw o retractor s tha t fuse . Thi s latte r i s probabl y the cas e fro m wha t w e krro w abou t th e developmen t o f thčs e organisms . Ilowever , t o b e consistant wit h th e literatur e o f thi s genus , i t migh t b e bes t t o sa y a singl e retracto r wit h two roots . Thčs e root s originat e near , bu t no t at , th e posterio r en d o f th e trun k i n a norma l fashion. In thi s subgenu s ther e ar e tw o specie s tha t hav e bee n describe d a s havin g on e retracto r with tw o roots , a posteriorl y attache d spindl e muscle , an d withou t hooks . I t differ s fro m both o f thčse , tha t i s A. albus an d A. venabulus, i n th e angl e a t whic h th e introver t corne s off (40­45° ) an d als o th e natur e o f th e shield s whic h i s quit e différen t tha n bot h thos e tw o species.

The nam e i s i n hono r o f Dr . Berrrar d A . THOMASSI N wh o collecte d ai l bu t on e o f thčs e spécimens plu s man y other s i n thi s repor t a s par t o f hi s studie s o n th e biolog y o f cora l reefs.

The typ e materia l ha s bee n deposite d i n th e Muséu m nationa l d'Histoir e naturelle , Paris . Holotvpe : Cat . n ° AH­40 6 ; B T Sta . 45 2 ; " devan t labo. , Ilo­Ilo , seagras s be d " . Paratype s : Cat. n ° AH­40 7 ; B T Sta . 41 9 ; " Béci f d e Songoritel o " ; Cat . n ° AH­40 8 ; BT Sta . 13 6 ; " Gran d Récif " , Tuléar . - 974 —

Aspidosiphon (Paraspidosiphon) angulatus (lkeda , 1904 )

Moorea B T Sta . 27 , 1 8 spec . Tuléar B T Sta . 678 , 1 spec . seagras s be d o n ree f flat .

Thčse 1 9 spécimen s wit h unidentat e hook s (15­2 5 [x m high ) an d retracto r muscl e ori ­ gins i n th e thir d quartc r o f th e trun k rang e i n siz e fro m 3­2 7 m m (mos t les s tha n 1 0 mm) . The hook s ar e colorles s an d ther e i s som e variabilit y i n th e angl e a t whic h th e point s ar e bent. Th e introver t i s longe r tha n th e trunk . Th e ana l shiel d ha s fewe r tha n 1 0 longitu ­ dinal groovc s dorsall y whic h ru n int o a compac t centra l are a an d the n becom e mor e diffus e and granula r ventrally . Th e border s o f tin s shiel d ar e no t shar p a s th e hardene d papilla e become scattere d an d graduall y decreas e i n siz e t o merg e wit h th e trun k papillae . Th e caudal shiel d ha s abou t 25­3 0 radiatin g groovcs . Th e transparen t t o off­whit e trun k usually allow s th e longitudina l muscl e band s t o b e see n fro m th e outside . Thčs e ar e no t strongly develope d eve n i n th e large r worm s an d a s STEPHE N & EUMOND S (197 2 : 241 ) point out , " longitudina l muscle s incoinpletel y divide d int o frequentl y anastomosin g bundles. " The nephridi a ar e abou t hal f a s lon g a s th e trunk , attaehe d fo r hal f t o tw o third s thei r length an d ope n jus t posterio r t o th e anus . N o caecu m wa s see n o n th e shor t rectum . Ihe contractil e vesse l i s simpl e an d a stron g spindl e muscl e anchor s bot h end s o f th e gu t coil. Mos t o f thčs e spécimen s wer e uncoiled , on e large r on e ha d live d i n a scaphopo d shel l and onl y on e ha d clearl y inhabite d a gastropo d shell .

DISTRIBUTION. — Th e tw o existin g record s fo r thi s specie s ar e fro m th e Wes t Carolin e Islands an d Japan . Th e spécime n fro m Sta . 67 8 represent s th e first India n Océa n repor t for thi s for m whic h appear s t o b e anothe r membe r o f th e Indo­Wes t Pacifi c shallo w wate r fauna.

Aspidosiphon (Paraspidosiphon) klunzingeri (Selenka , d e Ma n N Bulow , 1883 )

IIOE Sta . 1 6 ; 1 spec . ; 8/3/63 ; 21°02 ' N , 157<>41 ' W ; 4 8 m ; Molokai , Hawaii . — 390 S ; 3 spec . ; 9/9/64 ; 29°35 ' S , 31°42 ' E : 13 8 m ; Durban . Tuléar B T Sta . : 18, 1 spec . ; 257, 1 ; 615, 2 ; 637, 1 ; 650, 1 . Fort­Dauphin, DECAR Y coll. , 1932 , 1 spec .

Thčse 1 6 spécimen s wer e difοicul t t o assig n t o thi s taxon . Th e allege d différence s between A. cumingii an d A. klunzingeri ar e no t clearcu t an d th e literatur e ove r th e year s has severa l inconsistancies . Accordin g t o STEPHE N év : EDMOND S (1972 ) A. cumingii ha s a recta l caecu m an d contractil e vesse l vill i whil e A. klunzingeri doe s not . Als o A. cumingii has 27­3 8 longitudina l muscl e band s whil e A. klunzingeri ha s 38 . However , earlie r author s have reporte d contrar y dat a and/o r opinions , an d th e choic e o f thi s nam e fo r thčs e orga ­ nisms i s somewha t arbitrary . I t i s hope d tha t a carefu l analysi s o f thi s comple x ca n b e made i n th e futur e (se e als o CUTLER , 1977) . — 975 —

Most o f th e worm s ar e aroun d 10­1 5 m m bu t rang e i n trun k lengt h u p t o 4 0 mm . Single­pointed hooks , measurin g u p t o 7 0 p m i n th e larges t worm , ar e arrange d i n row s but ar e scattere d mor e proximally . Th e dar k brow n ana l shiel d ha s abou t 1 2 shor t groove s dorsally whic h degenerat e t o th e coars e granula r ventra l région . Th e cauda l shiel d ha s more groove s bu t otherwis e i s simila r t o th e ana l shield . Internally th e pai r o f retracto r muscle s originat e a t th e cauda l shiel d an d a spindl e muscle anchor s th e gu t coi l a t bot h ends . A recta l caecu m i s présent . Th e nephridi a ar e variable i n positio n an d attachment . I n th e 4 0 m m wor m fro m Sta . 16 , on e nephridiu m is muc h shorte r tha n th e othe r an d ha d a secondar y lobe . Thi s i s considere d t o b e a n ano ­ moly. There ar e thre e spécimen s fro m Anto n Bruu n Sta . 390 S whic h migh t b e thi s specie s but thei r smal l siz e (4­ 6 mm ) an d ou r uncertaint y cause d u s t o refrai n fro m makin g a posi ­ tive identification .

DISTRIBUTION. — Excep t fo r on e repor t fro m Durban , thčs e ar e th e first record s fro m the southwester n India n Océan . I t ha s bee n foun d i n th e norther n an d wester n par t a s well a s th e Re d Sea , Funafuti , an d th e Grea t Barrie r Reef . Th e Hawai i recor d i s a ne w eastward extension . I t ha s als o bee n foun d o n bot h side s o f tropica l Atlanti c Océa n bu t not ye t fro m th e Easter n Pacific .

Aspidosiphon Paraspidosiphon) speculator (Selenka , 1885 )

IIOE " T e Veg a " Sta . 4 5 ; 1 spee. — Sta . 45­ 4 ; 5 spee . 9/10/6 3 ; 6° 12 ' N , 155°37 ' E ; 32 m ; Bou ­ gainville Island , Solomons . — Sta . 45­ 8 ; 1 1 spec . 9/10/6 3 : 6°12' N , 155°39 ' E ; 2 m ; Bougain ­ ville Island , Solomons . — Sta . 8 2 L H 1 0 ; 11/06/6 3 ; 9°26 ' N , 97°54 ' E ; 1 m ; Thailand. ' Tuléar P G Sta . 4 4 ; 1 spec . oute r boulde r ree f tract . — B T Sta . : 154 , 1 spec. ; 240 , 1 spec . ; 270 , 1 spec . ; i n coars e an d gravel y sands .

ihc trun k lengt h o f thčs e 2 2 worm s rang e fro m 3­2 7 mm . Th e bod y wal l i s trans ­ parent excep t nea r th e tw o end s i n large r one s wher e i t become s thic k an d rough , leathery , almost cork y looking . Th e granula r o r warty , ungrooved , smoot h ana l shiel d i s gol d t o dark brow n wit h moderatel y distinc t borders , whil e th e cauda l shiel d i s ver y indistinc t and weakl y chitinized . The introvert , whic h i s abou t a s lon g a s th e trunk , bear s row s o f bidentat e hook s but als o ha s scattere d unidentat e hook s mor e proximally . Th e orientatio n o f th e hoo k on th e slid e coul d mak e i t appea r a s a tetrahedro n wit h a les s sharpl y ben t poin t a s state d in STEPHE N & EDMOND S (1972) . I n thei r ke y t o thi s taxon (p . 239 ) i t i s necessary t o assum e this specie s ha s onl y bidentat e hooks . Internally th e anastomosin g longitudina l muscl e band s numbe r aroun d 2 4 o r less . The tw o root s o f th e retracto r muscl e originat e nea r th e cauda l shiel d an d a stron g spindl e muscle anchor s bot h end s o f th e gu t coil . A recta l caecu m i s présen t an d th e win g muscle s are wel l developed . Th e shor t nephridi a ar c partiall y attache d an d ope n a t o r just posterio r to th e leve l o f th e anus . — 97 6 —

DISTRIBUTION. — Th e tw o previou s record s fo r thi s specie s ar e fro m Cap e Verd e Island s and th e Gul f o f Guinea , : o thčs e Madagascar , Thailand , an d Solomo n Islan d worm s repre ­ sent a remarkabl e extensio n o f th e rang e i n th e wester n India n an d Pacifi c Océans .

Aspidosiphon (Paraspidosiphon) steenstrupi Diesing , 185 9

IIOE Sta . 40 7 I ; 9 spec ; 10/14/64 ; 17°19 ' S , 43°14 ' E ; 5 8 m; N W Majunga , Madagascar . — B­3 ; 3 spec . ; 2/9/63 ; 12°00 ' S . 9f>°50 ' E ; 1 m ; Cocos­Keelin g Island s ; reef. — B­ 5 ; 2 spec. ; 1/24/63 ; 12°00 ' S , 96°50 ' E ; 1 m ; Cocos­Keelin g Island s ; lagoon .

Thčse ar e 1 4 représentation s o f thi s wid e sprea d specie s wit h double­pointe d hook s and tw o retracto r muscle s originatin g i n fron t o f th e cauda l shield . Th e tightl y packe d rows o f hook s hav e th e smal l tubula r papilla e betwee n them . Th e dar k ana l shiel d i s granular o r wart y an d ma y hav e chalk y deposit s o n it . Th e ill­define d cauda l shiel d ha s vague groove s o n it .

DISTRIBUTION. — Thi s specie s occur s i n th e Caribbea n fro m Cub a t o Brazi l ; Cap e Verde Islands , Sout h Africa , lie d Sea , Mauritius , an d severa l othe r India n Océa n location s through Indonesi a t o Japan , Australia , an d severa l Wes t Pacifi c Islands . J n othe r words , this i s a circumtropiea l specie s excep t fo r th e caster n Pacific .

Aspidosiphon (Paraspidosiphon) truncatus Keferstein , 186 7

IIOE Sta . E C 2 1 ; 3 spe c ; 8/22/64 ; 25°57 ' S , 33°02 ' E ; 1 m ; Inhac a Island s ; rock .

Thčse thre e worm s rang e i n trun k lengt h fro m 7­1 8 m m an d bea r colorless , single ­ pointed hook s 25­3 5 (.'. m hig h i n rows . Th e médiu m brow n ana l shiel d ha s distinc t border s and ha s anastomosin g groove s dorsally , becomin g granular , wit h a n are a o f cone­shape d spikes aroun d wher e th e introver t protrudes . Th e cauda l shiel d i s groove d an d simila r in colo r t o th e trun k whic h i s thic k wallcd . Th e pai r o f retracto r muscle s ru n th e lengt h of th e bod y an d th e nephridi a ope n a t th e leve l o f th e anus .

DISTRIBUTION. — Th e know n rang e o f thi s specie s ha s som e peculia r gap s i n it . I t has bee n recorde d i n th e Caribbea n bu t no t of f Wes t Africa . I t occur s i n th e Re d Sea , several place s alon g th e caster n Africa n coas t an d Madagascar , the n appear s i n Japa n and th e Sunda y an d Loyalt y Islands . Thi s collectio n fro m Mozambiqu e fit s i n wit h a species whic h seem s t o inhabi t onl y th e wester n margin s o f thre e Océans .

Aspidosiphon (Paraspidosiphon) ochrus n . sp .

IIOE Sta . 40 7 I ; 4 spec ; 10/14/6 4 ; 17°19 ' S , 43°14 ' E ; 5 8 m N W o f Majunga , Madagasca r ; coral. ­ B­ 5 ; 2 spe c ; 1/24/6 3 ; 12°00 ' S , 96°50 ' E ; 1 m ; Cocos­Keelin g Island s ; lagoon . — 45­ 4 ; 5 spec . ; 9/10/6 3 ; 6°12 ' S , 155°37 ' E ; 3 2 m ; Bougainvill e Island , Solomon s ; coral . — H A 67­32 ; 2 spe c ; 8/5/67 ; 7°21 ' S , 72°28 ' E ; 1 m ; Dieg o Garcia . Tuléar P G Sta . 4 ; 1 spec . ; boulder ree f tract . — 97 7 —

This for m ha s th e typica l Aspidosiphon appearance . Th e trun k siz e range s fro m 9­20 m m i n lengt h an d 1.5­ 5 m m i n diameter . Th e introver t i s approximatel y th e sam e length a s th e trunk , perhap s slightl y longe r i n some . A t th e ti p ar e normal , smal l aspido ­ siphonid tentacles . Double­pointe d hooks , arrange d i n 20­4 0 rings , ar e présent . Thi s area i s usuall y followe d b y a mor e proxima l régio n o f scattere d hooks . Th e heigh t o f th e hooks i n ring s range s fro m 36­5 0 pim . O n som e individuals , proxima l t o th e hooke d area , the introver t exhibit s darkl y pigmente d band s o r région s simila r t o som e Phascolosoma. Between th e row s o f hook s on e ca n fin d tubula r cylindrica l papilla e approximatel y th e same heigh t a s the hooks . N o othe r papilla e ar e see n o n th e introver t no r ar e ther e obviou s papillae o n th e trun k (fig . 15) . The ana l shiel d (fig . 16 ) i s a strikin g cream y ta n an d pale r tha n th e surroundin g brow n trunk an d wit h distinct , shar p boundaries . Th e shiel d i s compose d o f uniform , densely ­ packed, wart­lik e unit s simila r t o A. steenstrupi. Th e cauda l shiel d i s muc h les s distinc t having ill­define d border s an d bein g onl y slightl y darke r brow n i n colo r an d thickene d epidermis wit h radiatin g grooves . I n a fe w spécimen s th e centra l régio n o f th e posterio r

Vie. 15 . — Aspidosiphon ochrus n . sp . : A , whol e anima l (scal e = 3 mm ) ; B , hoo k (scal e = 2 0 p.m) . FIG. — Aspidosiphon ochrus n . sp . Anal shield . end o f th e trun k wa s withdraw n o r sucke d i n formin g a smal l dépression . I t give s th e appearance o f a callouse d epidermi s rathc r tha n a chitinou s o r calcareou s structur e (fig . 17) . Internally th e intestin e i s anchorc d posteriorl y b y th e spindl e muscle . Th e rectu m is fastened nea r th e anu s b y a normal win g muscl e ; no caecu m wa s observed . Th e nephridi a are straight , abou t on e hal f a s lon g a s th e trunk , an d ar e attache d fo r mos t o f thei r lengt h to th e bod y wall . Th e nephridiopore s ar e slightl y posterio r t o th e anus . Th e pai r o f retractor muscle s originat e nea r th e posterio r en d fro m broa d hase s spanin g 5­ 8 longitu ­ dinal muscl e bands , an d ar e fuse d int o a singl e muscl e fo r abou t on e hal f thei r length. Th e 25­30 longitudina l muscl e band s anastomos e frequently . This ne w specie s wit h double­pointe d hook s an d tw o retracto r muscle s i s closel y rcla ­ ted t o A. steenstrupi. Th e mos t obviou s distinctio n i s th e muc h pale r ana l shield . Th e name o f this specie s i s Gree k fo r pal e o r ligh t colored . Th e retractor muscle s originat e close r to th e posterio r end , ther e ar e mor e longitudina l muscl e bands , an d th e nephridi a ar e atta ­ ched mor e coinpletely .

The typ e materia l ha s bee n deposite d i n th e Muséu m nationa l d'Histoir e naturelle , Paris . Ilolotype : Cat. n ° AIl­404 ; " Anto n Bruu n " Sta . 40 7 I ; NW Majunga , Madagascar . Paratype s : Cat. n ° AH­40 5 ; " T e Veg a " Sta . 45­ 4 ; Bougainvill e Island . — 97 9 —

FIG. 17 . — Aspidosiphon ochrus n . sp . Cauda l shiel d : A , contracte d stat e ; I> , relaxc d state . (Scale = 1 mm. )

Lithacrosiphon cristatu s (Sluiter , 1902 )

IIOE Sta . 45­ 4 ; 1 spec. ; 9/10/63 ; 6°12' S , 155°37 ' E ; 32 m ; Bougainville Island , Solomon s ; coral .

This 2 0 X 2 m m wor m ha s it s introver t completel y withdraw n bu t bot h bidentat e and unidentat e hook s wer e observed . Th e nephridi a ar e abou t 7 0 % o f th e trun k lengt h and th e ana l shiel d i s grooved . Thi s specie s an d relate d form s wer e discusse d a t lengt h — 98 0 — in a récen t revie w pape r (CUTLE R & JURCZAK , 1975 ) wher e i t wa s redescribe d an d no w includes L. alticonus, L. gurjanovae, L. indicus an d L. odhneri a s junio r synonyms .

DISTRIBUTION. — Thi s wester n Pacifi c recor d fits i n wit h th e know n distributio n pattern o f thi s specie s whic h i s somewhat unique . I t i s know n fro m Brazil , th e Caribbean , west coas t o f Panama , Hawaii , Gilber t Islands , Siapan , Timor , an d Malay a bu t n o furthe r into th e India n Océa n ; a wester n Atlanti c an d Pacifi c Océa n tropica l species .

Lithacrosiphon maldivensis Shipley , 190 2

IIOE Sta . 40 7 I ; 6 spec . ; 10/14/6 4 ; 17°19 ' S , 43°14 ' E ; 5 8 m ; N W o f Majunga , Madagasca r ; coral. — B­ 3 ; 2 spec . ; 2/9/6 3 ; 12°00 ' S , 96«50 ' E ; 1 m ; Cocos­Keelin g Island s ; reef . — B­5 ; 1 spec . ; 1/24/6 3 ; 12°00 ' S , 96°50 ' E ; 1 m ; Cocos­Keelin g Island s ; lagoon .

Only fou r o f thčs e hav e complčt e trunk s an d thei r lengt h varie s fro m 10­1 5 mm. Som e of th e other s wer e apparentl y large r bu t thi s canno t b e determined . Ai l o f thčs e sho w the ungrooved , smooth , slightl y granula r ana l shiel d characteristi c o f thi s species . Seve n of thčs e animai s hav e bee n previousl y reporte d i n CUTLE R & JURCZA K (1975 ) wher e thi s genus wa s reviewed . Th e si x worm s fro m Sta . 40 7 I sho w a n interestin g transitio n fro m the smallest , whos e ana l shiel d ha s jus t a smal l do t o f calcareou s materia l o n it s tip , throug h intermediate siz e t o large , whic h ha s a tall , smooth , cone­shape d mas s o f whit e materia l to th e larges t wher e thi s ha s itsel f becom e ovcrgrow n wit h othe r organisms , givin g a n irre ­ gular shap e t o it . HUCHE S (1974 ) provide s a detaile d descriptio n o f thi s species .

DISTRIBUTION. — Thčs e record s fro m bot h side s o f th e India n Océa n supplémen t th e previous Indo­Wes t Pacifi c record s fro m th e Be d Sea , Maldiv e Islands , Saipan , an d Gilber t Islands.

Cloeosiphon aspergillus (Quatrefages , 1865 )

IIOE Sta . 40 7 I ; 3 spec ; 10/14/64 ; 17°19 ' S , 43°14 ' E ; 5 8 m ; N W o f Majunga , Madagascar ; coral. — B­ 5 ; 1 spec . ; 1/24/6 3 ; 13°00 ' S , 96°50 ' E ; 1 m ; Cocos­Keelin g Island s ; lagoon . ­ JR­18 ; 1 spec. ; 12/30/6 3 ; 13°31 ' S , 48°20 ' E ; 4 m ; Nos y Bé . — 8 2 L U 1 0 ; 4 spec . ; 11/6/63 ; 9026' N , 97°54 ' E ; 1 m ; Thailand. — 8 7 L H 1 7 ; 3 spe c ; 11/15/6 3 ; 7o40 ' N , 98o48 ' E ; 1 m ; Thailand. Tuléar P G Sta . : Many spécimen s (380 ) collecte d i n th e rock y substrat e o n th e oute r boulde r tracts .

Thčse 42 0 worm s o f thi s wel l know n an d distinctiv e specie s var y i n trun k lengt h fro m 10­82 mm . Th e uniqu e ana l shiel d make s i t possibl e t o easil y identif y thi s specie s eve n when onl y a n incomplčt e spécime n i s collected , whic h i s tru e fo r man y o f thčse . I t i s only foun d i n cora l an d i s sometime s damage d i n th e extractio n process .

DISTRIBUTION. — Thi s specie s ha s bee n reporte d numerou s time s fro m throughou t th e Indo­West Pacifi c shallo w wate r région . — 98 1 —

Centrosiphon sp .

Tuléar B T Sta . : 222, 1 spec . ; 436, 1 ; 822, 1 ; in fine t o coars e sands , o n th e dee p par t o f the oute r reef slope , o n th e lagoona l bottoms , an d in th e littora l terrigenou s seagras s bed .

Thčse uniqu e worm s see m t o fit SHIPLEY' S genus , bu t ar e no t Centrosiphon herdmani (Shipley, 1903) . Hi s specie s ha d fou r retractor s ; thi s ha s onl y a singl e pair , fuse d fo r most o f thei r lengt h an d havin g thei r origin s abou t a thir d o f the distanc e fro m th e anterio r

FIG. 18. — Centrosiphon sp . wit h introver t retracted . (Scal e = 2 mm. ) AS = ana l shiel d ; C S = cauda l shield . — 98 2 — end o f th e trunk . Th e largest , ligli t brow n on e fro m Sta . 43 6 ha s a trun k 1 0 X 2 m m an d the introvert , whil e withdrawn , i s 1.5­ 2 time s thi s length . Th e ski n lia s fain t transvers e and longitudina l line s o n it s surface . Th e trun k o f th e smalles t one , fro m Sta . 822 , i s 4 X 1 mm an d transparent . Ther e ar e dar k hook s i n 15­2 0 row s whic h ar e abou t 30­4 0 pi n in height . Digitifor m tentacle s ar e présen t an d numbe r aroun d 20 . Th e wor m fro m Sta . 222 ha s a 5 m m trun k an d a n 8 m m introver t an d i s i n poo r condition . Internally th e coile d gu t i s not anchore d posteriorl y b y th e spindl e muscl e an d a recta l caecum i s présent . Th e pai r o f shor t nephridi a ar e attache d t o th e bod y wal l fo r abou t one hal f thei r lengt h an d ope n slightl y anterio r t o th e anus . Th e contractil e vesse l i s simple. The characte r whic h force s u s t o plac e thčs e spécimen s i n thi s ai l bu t forgotte n taxo n (there hav e bee n n o report s sinc e SHIPLEY' S origina l recor d ove r 7 0 year s ag o an d bi s typ e material cauno t b e located ) i s th e natur e o f th e ana l shiel d an d th e fac t tha t th e introver t protrudes throug h th e center . Bot h shield s consis t o f smooth , hardened , chitinoi d materia l subdivided b y narro w groove s o r furrows . Th e 1 0 mm wor m ha s abou t 3 4 groove s i n th e caudal shiel d an d 2 8 i n th e ana l shield . Thčs e structure s hav e distinc t border s wher e they mee t th e trun k an d both , whil e obviousl y ilexible , hav e th e gęnera i for m o f tw o broa d cτnes fuse d a t th e larg e en d (fig . 18) .

Phascolosoma (Satonus) pectinatum Keferstein , 186 7

Tuléar B T Sta . 12 4 ; 1 spec . oute r boulde r ree f traet .

This uniqu e specie s wit h bilobe d nephridi a an d spinelet s o n th e bas e o f th e pal e intro ­ vert hook s i s represente d b y onl y a singl e wor m whos e trun k i s 2 2 m m long . Th e longitu ­ dinal muscl e band s ar e no t stron g an d anastomos e frequently , th e spindl e muscl e i s no t attached posteriorly , th e retracto r muscle s ar e rallie r thin , an d th e coelo m i s packe d wit h sperm.

DISTRIBUTION. — Th e know n distributio n o f thi s specie s include s th e Caribbean , ΐzores , Mauritius, Surinam , Tasma n Sea , Eas t Chin a Sea , souther n Californi a an d Panam a i n th e eastern Pacific , s o thi s i s onl y th e secon d recor d fro m th e India n Océa n o f wha t ma y b e a n uncommon circumtropica l species .

Phascolosoma (Phascolosoma agassizii Keferstein , 18(5 7

IIOE Sta . : KA 1 3 ; 1 spec . ; 1/22/6 4 ; 11°45 ' S , 42°15 ' E ; 1 m ; Grand Comor e Island . H A 67­4 0 ; 2 spec . ; 7/10/6 7 ; 7°21 ' S , 72°28 ' E ; 1 m ; Dieg o Garcia .

Thčse thre e smal l spécimen s hav e trunk s 8­1 4 m m lon g an d ar e thic k skinne d wit h papillae uniforml y distribute d ove r thei r surface . Th e hook s ar e abou t 5 0 p m hig h an d notched o n th e concav e sid e i n a manne r whic h sometime s almos t give s th e appcaranc e o f a bidentat e hook . Ther e ar e 2 3 o r 2 4 longitudina l muscl e bands , a posteriorl y attache d — 98 3 — spindle muscl e an d th e nephridia , whic h ar e abou t 2/ 3 attached , ope n jus t posterio r t o the anus .

DISTRIBUTION. — Ther e ar e severa l report s fro m Wes t Afric a an d the n aroun d Cap e Province, Durban , severa l India n Océa n records , Indo­China , Australia , an d the n alon g the Pacifi c coas t o f th e Unite d States . I t seem s t o b e absen t fro m th e wester n Atlanti c Océan an d Centra l America n waters .

Phascolosoma (Phascolosoma) albolineatum Baird , 186 8

IIOE Sta . : H A 67­1 0 ; 2 0 spec . ; 7/10/6 7 ; 7°21 ' S , 72°28 ' E ; 1 m ; Dieg o Garcia . — H A 67­4 6 ; 6 spec . ; 7/18/6 7 ; 7°22 ' S , 72029 ' E ; 1 m ; Dieg o Garcia .

Thčse 2 6 pal e worm s hav e trunk s varyin g i n lengt h fro m 11­4 8 m m an d man y hav e gamčtes i n th e coelom . Th e introver t i s abou t hal f th e trun k length , carrie s dar k re d papillae proximall y an d bear s row s o f hook s wit h strongl y ben t points . Th e clea r strea k in thčs e hook s varie s i n length , ofte n bein g shorte r tha n tha t illustrate d i n STEPHE N & EDMONDS (197 2 : fig . 33A) . înternall y th e nephridi a ope n a t th e leve l o f th e anus , ar e a littl e les s tha n hal f th e trun k lengt h an d ofte n attac h fo r les s tha n hal f thei r length , not three­fourth s a s earlie r noted . The uniqu e featur e i n thi s populatio n i s th e retracto r muscle s : ther e ar e two , three , and fou r muscle s i n différen t animais . Th e norma l conditio n i s tw o pair s i n whic h th e dorsal muscl e i s smalle r an d shorte r tha n th e ventral s an d quickl y merg e wit h th e ventra l muscle o n th e sam e side . I t i s apparen t tha t thi s fusio n become s complčt e o n on e o r bot h sides i n som e worm s wit h th e résultan t los s o f a separat e dorsa l retracto r muscle . A simila r situation wa s describe d b y GIBB S (1973 ) i n a populatio n o f Golfingia rimicola. Thi s occa ­ sional occurrenc e o f a n anomolou s conditio n doe s no t necessitat e th e créatio n o f a ne w taxon.

DISTRIBUTION. — Th e earlie r record s fro m th e India n Océa n ar e fro m Nata l an d Amboina. I t ha s als o bee n recorde d fro m Java , Indo­China , Japan , an d a fe w Wes t Paci ­ fic Islands , s o thi s recor d reinforce s it s shallo w water , Indo­Wes t Pacifi c character .

Phascolosoma (Phascolosoma) funafutiense (Fischer , 1914 )

IIOE Sta . : H A 67­4 0 ; 1 4 spec . ; 7/10/67 ; 7°21' S , 72°28 ' E ; 1 m ; Dieg o Garcia . MC Sta . : 1 1 ; 4 spec . ; 8/14/7 0 ; 11°21 ' N , 162°22 ' E ; 1 m ; Eniwetok . — 1 3 ; 3 spec . ; 9/30/70 ; 11021' N , 162°22 ' E ; 1 m ; Eniwetok .

Thčse pal e spécimen s see m t o fit thi s uncommo n species . Th e peculia r hoo k structur e (STEPHEN & EDMONDS , 197 2 : fig. 37C ) wit h th e smal l toe­lik e plate s a t th e posterio r bas e are quit e distinctive . Thčs e population s rang e i n trun k lengt h fro m 11­7 0 mm . Th e nephridia ope n a t th e leve l o f th e anu s an d ar e a s lon g a s th e trunk . Ther e ar e fou r retrac ­ tor muscles . Th e dorsa l pai r originat e 2/ 3 th e distanc e t o th e posterio r o f th e trun k an d — 98 4 — the ventra l pai r originat e 3/4 of the distance. Thi s i s further posterio r tha n previousl y noted.

DISTRIBUTION. — Th e two previous record s ar e fro m Funafut i an d the Christma s Islands, s o thi s Dieg o Garci a recor d constitute s a westwar d extensio n int o th e India n Océan.

Phascolosoma (Phascolosoma) nigrescens Keferstein , 1865

IIOE Sta . B­4 ; 1 spec. ; 2/7/63 ; 12°00' S , 96°50' E ; 4 m ; Cocos­Keeling Islan d ; reef. — EC 21 J ; .271 & 152 ; 2 & 4 spec spec . ; 8/22/64 ; 25°57' S, 33°02' E ; 1 m ; Inhaca Islan d ; rock. — R١ 1 11/22/64 ; ll°40­47 ' S , 43°16 ' E ; 2­3 m ; Gran d Comor e Island . — 18 A ; 3 spec . ; 3/21/63 ; 7°35' N , 98°08 ' E ; 7 4 m ; S W o f Sumatra . — 4 7 B ; 2 spec . ; 4/5/6 3 ; 19°50 ' N , 92°55 ' E ; 26 m ; Bay of Bengal. — 372 P & I) ; 4 spec. ; 8/19­22/64 ; 25°50' S , 34°49' E ; 19­37 m ; Sout h Mozambique. — 381 A& B ; 2 spec . ; 8/19­22/6 4 ; 33°13 ' S , 43°51 ' E ; 38­4 6 m ; S. of Mada ­ gascar. — 407 I ; 1 spec. ; 10/14/6 4 ; 17°19 ' S , 43°14' E ; 58 m ; NW Majunga, Madagascar . — 447 , 449, 453 ; 1 0 spee . ; 12/16/6 4 ; 10°­11°11 ' N , 51°15 ' E ; 35­6 0 m ; Somalia­Gul f o f Aden. — HA 67­32 ; 7 spec. ; 8/5/67 ; 7°21' S, 72°28' E ; 1 m ; Diego Garcia . 18 station s by J. RUDI.OE ; 98 spec. ; 12/19/63­2/7/64 ; approx. 13°25 ' S , 48°20' E : 1­ 4 m ; Xos y Bé, Madagascar. Nosy B é BT Sta. : 500, 2 spee. ; Enhalus acoroides seagras s bed . Tuléar P G Sta. : 35, 1 spec. ; 39, 1 ; outer ree f boulde r tracts . — BT Sta . : 20 spec. in 14 sta. dis­ truted o n the reef slope s an d flats. Fort­Dauphin, DF.CAR Y coll. , 193 2 : 6 spec .

This widel y distribute d specie s i s represented b y 180 spécimens rangin g i n trunk lengt h from 1.5­7 0 mm, most betwee n 20 and 40 mm. I n a few of the very smalles t one s (2­ 3 mm) the band s o r bundles o f longitudinal muscle s ar e extremely difοicul t t o discern. STEPHE N & EDMONDS (197 2 : 317) commenting abou t longitudina l muscl e band s i n P. pacificum said , " .. . except i n very youn g spécimen s wher e the y ma y be continuons. " So , it is possibl e that thčs e hav e no t developed yet . RIC E (197 3 : 6) w rhile describin g th e development o f P. agassizii say s : " The adul t arrangemen t o f longitudinal muscle s int o bundle s o f fiber s is not discernable i n the larva. " I t seems logica l to assert tha t thi s importan t characte r has no t yet appeared i n the 2 and 3 mm animais i n our collection. Therefore , i f generi c features ar e not visible a t thi s stage , specie s character s ar e probably undevelope d also . In thčs e ver y smal l worm s the introvert i s shorter tha n th e trunk. Thčs e worm s hav e the spindle muscl e attache d posteriorly , nephridi a whic h ar e about hal f attache d an d ope n at th e same leve l a s the anus.

A fina l not e abou t hoo k siz e and the clear streak . I n CUTLER (1965 ) thi s wa s discusse d and the conclusion wa s reached tha t th e hook siz e wa s variable but not in direct proportio n to trun k lengt h (CUTLER , 196 5 : fig. 5) . Th e size rang e o f the spécimens analyze d was from 25­10 0 m m and hook heigh t fro m 48­9 2 pm . Thi s récen t collectio n allowe d u s to extend tha t analysi s to the lower siz e range s (1.5­ 5 mm) . Thi s i s shown i n figure 19 . The smaller animai s clearl y hav e smalle r hook s (abou t 20­3 0 pin) . I t now looks a s if the hoo k size increase s rapidl y whil e the worm grow s to 30 or 40 mm, level s of f at a plateau aroun d 65­75 pm until the worm exceed s 80 mm, and then increase s to around 90 pm. Thi s appa ­ rent secon d growt h spur t i n larger worm s ma y be unreal. A most interestin g contributio n — 98 5 — has recentl y bee n mad e b y BERTSC H (1976 ) wherei n h e describe s ontogeneti c radula r varia ­ tion i n opisthobranch s an d arrive s a t ver y simila r conclusion s fro m ver y simila r data . The fixed, absolut e characte r o f th e clea r strea k i n thčs e hook s i s inaccurate . On e can fin d o n man y worms , upo n carefu l examinatio n o f a larg e numbe r o f hooks , a t leas t a fe w i n whic h ther e i s a suggestio n o f a séparatio n o f a triangula r are a a t the anterio r basa i région, simila r t o tha t foun d i n P. scolops.

DISTRIBUTION. — Thi s i s a commo n circumtropica l shallo w wate r species . Thčs e records firml y establis h it s wid e présenc e throughou t th e India n Océan .

100

55 ' 40 " 1 &5 ' §& ' îoÔ '

TRUNK LENGT H I N M M

FIG. 19 . — Phascolosoma nigrescens. Relationshi p betwee n trun k an d lioo k size . Calculatin g a simpl e linear régressio n ( Y = A + BX ) fro m thčs e dat a on e finds a positiv e slop e o f 0.62 . However , after . fitting severa l curves , th e bes t fi t (inde x o f déterminatio n o f 0.95 ) i s a powe r functio n Y = A ­f ­ X B.

Phascolosoma (Phascolosoma! pacificum Keferstein , 186 6

IIOE Sta . : H A 67­3 2 ; 1 0 spec . ; 8/5/6 7 ; 7°21 ' S , 72°28 ' E ; 1 m ; Dieg o Garcia . — H A 67­4 0 ; 4 spec. ; 7/10/67 ; 7°21' S, 72°28' E ; 1 m ; Dieg o Garcia . — H A 67­4 8 ; 1 spec. ; 7/20/67 ; 7°17' S, 72°28' E ; 1 m ; Dieg o Garcia . — H A 67­5 2 ; 1 spec . ; 7/24/6 7 ; 7°19 ' S , 72°29 ' E ; 1 m ; Diego

MC Sta . 1 1 ; 2 spec . ; 8/14/7 0 ; 11°21 ' N , 162°22 ' E ; 1 m ; Eniwetok . — 1 2 ; 1 spec . ; 8/28/70 ; 11021' N , 162°22 ' E ; 1 m ; Eniwetok . — 1 4 ; 1 spec . ; 9/30/7 0 ; 11°21 ' N , 162°22 ' E ; 1 m ; Eniwetok. Tuléar PG Sta. : 25 spec . collecte d i n 8 stations o n th e outer , ree f boulde r tracts . — B T Sta . : 4 spec. sampled i n 3 station s i n th e sam e biotope .

1, 10 ­ 98 6 —

Thčse 4 9 worms , rangin g i n trun k lengt h fro m 25­12 5 mm , sho w 35­4 0 longitudina l muscle bands , th e hoo k structure , lon g attaehe d nephridia , an d stron g spindl e muscl e typical fo r thi s species . Mos t distinctiv e i s th e unifor m distributio n o f large , cone­shape d papillae o n th e trun k (fig . 20) . Ou r observation s o n th e nephridia l openin g jus t anterio r to th e anu s an d th e lac k o f a recta l caecu m suppor t thos e o f EDMOND S (1956) . On e o f our worm s showe d peculia r orang e swelling s alon g th e esophagus . Anothe r on e exhibit s an interestin g featur e wher e som e o f th e hook s ar e evidentl y wor n dow n an d th e clea r streak goe s ou t th e top , suggestin g tha t thčs e wer e use d fo r abrasion . Som e o f th e large r hooks (105­12 5 [im ) sho w a peculia r hubble­lik e clea r blo b risin g u p fro m th e basa i clea r area an d th e triangula r clea r are a varie d i n siz e (fig . 21) . Thi s variet y ca n b e see n fro m a singl e wor m i n th e sain e ro w o f hooks .

DISTRIBUTION. — Man y report s o f thi s specie s clearl y sho w i t t o b e a wide­sprea d member o f th e Indo­Wes t Pacifi c shallo w wate r l'amil y bu t no t a s numerou s a s som e othe r members o f thi s genus . I t ba s previousl y bee n foun d i n Madagascar . A singl e repor t (HALDER, 1975 : 60 ) fro m 400­80 0 m i s i nusually dee p fo r thi s species .

FIG. 20 . — Phascolosoma pacificum. Papilla e fro m mie l trun k (Scanning électro n micrograpl i 10 0 X.i — 98 7 —

FIG. 21 . — Phascolosoma pacipcum. Introver t hook s showin g variatio n o f interna i structure . (Scale =•- • •3 0 u.m.)

Phascolosoma (Phascolosoma) perlucens Baird, 1868

Tuléar PG Sta. : 37 spec. collected in 15 stations on the outer reef boulder tracts.

Thèse 37 worms are in varying states of wholeness so sizes could not be accurately determined. They ranged up to 45 mm but many had their trunks damaged during their extraction from the coral. The large, posteriorly directed, preanal papillae and pale trunk make them easy to identify. Once again the supposedly characteristic triangular clear space in the hook varies in size and shape. This species was formerly known as P. alenli- gerum.

DISTRIBUTION. — This appears to be a circumtropical species but relatively uncommon in the Indian Océan. It has been previously reported from Madagascar.

Phascolosoma (Phascolosoma) scolops Selenka, de; Mari & Bulow, 1883

IIOE Sta. " Te Vega " 16 ; 2 spee. ; 8/3/63 ; 21°02' N, 157°41' W ; 48 m : Maolkai, Hawaii. — " Te Vega " 92 LU 20 ; 1 spec. ; 11/18/63 ; 7° 46' N, 98°21' E ; 1 m ; Thailand. — EC 21 ; 5 spec. ; 8/22/64 ; 25°57' S, 33°02' E ; 1 m ; Inhaca Island. — RU 242 ; 2 spec. ; 11/14/64 ; — 988 —

4°05' S , 39°40 ' E ; 1 m ; Mombassa . — 28 A : 2 spec . ; 3/27/6 3 ; 1 1°52' N , 95°50 ' E ; 6 2 m ; NE Nicoba r Island . — 206 A ; 44 spec . ; 11/15/6 3 ; 20°33' N , 70°09 ' E ; 43 m ; NW o f Bombav . ­ 269 C ; 1 1 spec . ; 12/3/6 3 ; 23°35 ' N , 58°49 ' E ; 12 2 m ; Gul f o f Oman . — 270 A ; 2 spec . ; 12/4/63 ; 22°07 ' N , 59°48 ' E ; 5 6 m ; Gul f o f Oman . — 372C , P & Q ; 8 spec . ; 8/19­22/6 4 ; 25°57' S , 33°00'­34°50 ' E ; 22­4 2 m ; South Mozambique . — 381 B ; 8 spec . ; 8/27/64 ; 33°13' S , 43°51' E ; 3 8 m : S . o f Madagascar . — 400 C ; 1 5 spec . ; 10/3/6 4 ; 20°00 ' S , 35°42 ' E ; 62 m ; Beira, Mozambique . — 453 , 45 6 ; 2 spec . ; 12/17/64 ; 11°11­14' N , 51°8­14 ' E ; 29­48 m ; Soma ­ lia. — H A 67­3 2 & 67­4 0 ; 1 1 spec . ; 8/5/67 & 7/10/6 7 : 7°21 ' S , 72°28 ' E ; 1 m : Dieg o Garcia . 12 station s b y J . RUDLOF . ; 2 4 spee . ; 12/19/63­1/15/6 4 ; approx. 13°25 ' S , 48°20 ' E ; 1­1 5 m ; Nos y Bé, Madagascar . Tuléar : PG Sta . : 30 spee . sample d i n 1 0 sta. o n th e oute r ree f boulde r tracts . — B T Sta . : 1 7 spec . collected i n 9 station s i n coars e sédiments , mor e frequentl y o n th e oute r ree f boulde r tract s and o n th e bottom s o f th e oute r ree f creek s an d sometime s o n th e oute r ree f slope . Fort­Dauphin, DECAK Y coll. , 193 2 : 1 2 spec .

This mos t commo n membe r o f th e genu s i s represente d b y 22 7 spécimen s rangin g i n trunk lengt h fro m 1.5­3 6 mm, mos t bein g aroun d 10­1 5 mm and , thereforc , generall y smalle r than P. nigrescens. I t als o difοer s externall y b y havin g a pale r overal l colo r an d redde r papillae. Th e clea r triangula r spac e a t th e bas e o f th e hoo k i s usuall y distinctive . Th e clear strea k runnin g dow n th e hoo k fro m it s ape x ma y var y somewha t i n siz e an d shap e from hoo k t o hook , no t ai l bein g straigh t an d o f unifor m width . Th e relationshi p betwee n trunk an d hoo k siz e seem s t o closel y parelle l th e pictur e fo r P. nigrescens : th e 2­ 5 m m worms havin g hook s abou t 20­3 0 (x m hig h an d the n increasin g u p t o 50­7 0 u. m i n a 2 5 m m worm. I n the smal l one s e.g. , thos e fro m Sta . 206A , the hook s ar e thi n an d pale , on e 1. 5 m m worm havin g onl y thre e row s o f hooks . Most o f thčs e animai s hav e a n introver t 1.5­ 2 time s th e trun k lengt h whic h ofte n ha s reddish brow n pigmente d blotche s o n a pal e background . A fe w o f th e smalles t worm s (less tha n 5 mm ) bea r introvert s a littl e shorte r tha n th e trunk . Th e nephridi a ar e abou t half a s lon g a s th e trun k o r shorte r i n ver y youn g ones , ope n nea r th e anu s an d ar e attache d to th e bod y wal l fo r abou t hal f thei r length . A fe w o f thos e fro m GALENON' S (PG ) station s resemble th e subspecie s mossambiciense havin g curve d dar k line s i n th e hook .

DISTRIBUTION. — Thi s specie s i s know n fro m throughou t th e tropica l sea s excep t fo r the easter n Pacific . Th e on e statio n nea r Hawai i ( " T e Veg a 1 6 " ) i s therefor e o f interest . The othe r record s reaffir m it s widesprea d présenc e i n shallo w wate r throughou t th e Ind o Pacific.

REFEBENCES

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Manuscrit déposé le 6 septembre 1977.