THE WASMANN JOURN A L OF BIOLOGY

Vol. 9, No. 3 F A LL, 1951

The of California (Cirripedia)

IRA EDMUND CORNWALL, 1951 A1·gyle Avenue, Vic­ to1"ia , BTitish Golttmbia

I NTRODUCTION

This paper deals only with the barnacles that are native to the coast of California. There are others such as the pelagic , L e1Jas fascicula1·is Ellis & Solander, and the whale barnacles, that are taken off the coast but they cannot be called Califo rnia barnacles. Darwin (1851 and1854) has indicated the parts of the barnacle that must be examined in order to make a valid identification. His method is still used as nothing better has been devised and his Monogmphs still constitute the standard work ou the subject. As Darwin has so emphatically stated, "there is not a single ex­ ternal character that can be used for identification. ' ' This is espe­ cially true of the shell. Plate I shows five of the many forms which may be assumed by the shell of Balanus car-iosus (Pallas). There are other that take these same forms and any one of these variations might be asstm1ed to constitute a species when judged by external appearance aloue. Much of the work on this paper was done at Hopkins Marine Station of Stanford University, Pacific Grove, California. At the time Dr. W. K. Fisher was the director. I wish to thank Dr. Fisher and also Dr. Rolf Bolin fo r their assistance. I also wish to ac­ knowledge help received from Dr. Waldo L. Schmitt of the United States National lVIuseum and from Dr. '1'. H. V\7ithers of the British Museum. To my son, Brooke Cornwall, goes the credit for making some of the drawings.

Received for publication 'ovember 15, 1950. [ 311] 312 THE WASMANN JOURNAL OF BIOLOGY, VoL. 9, 1951

All drawings in this paper were made by camera Iucida and as far· as possible were based on fresh specimens.

8

A

E

PLATE I

Examples of variation in the shell of Balanus ca1·iosus (Pallas).

Tetraclita squamosa rubescens Darwin. (Plate II, figures A and B.)

T etmclita squamosa 1·ubescens DAB WIN, 1854; PILSB RY , 1916, pages 257- 258. THE BARNACLES OF CALIFORNIA- CORNWALL 313

DISTRIBUTION : Farallon Islands, California, to Cape San Lucas, Lower California. This species occurs only in the intertidal zone. DJMENSIONS: Measurements were made of 3 specimens. These gave diameters of 35 nun., 28 mm., and 14 mm. respectively and heights of 15 mm., 13 mm., and 8 mm. respectively. DIAGNOSIS: Four plates forming the wall. Dark red shell. GENERAL APPEARANCE: The shell is dark red and appears to be of one piece as the sutures between the plates cannot be seen f rom t he outside. The surface of the shell is always eroded but some­ times there is a band near the base that is gray-white indicating t he natural color of the uneroded shell. 'fhe orifice is small in most specimens and its margin is irregularly toothed. The color of the sheath is the same as that of the shell There are several irregul ar rows of pores in the wall plates and these are larger than in a typical specimen ofT. sqttamosa. The outline of the shell is nearly a circle. 'l'he basis is membranous. ScUTUM: Plate II, figure B, numbers 1 and 2. Th e outline of the scutum is nearl.r triangular, except that the basal margin is curved. The growth lines on the exterior are prominent and the upper part of the plate is often eroded. Internally, the plate is white below the adductor ridge, Corinthian purple or deep hell e­ bore red above it. The adductor ridge is well developed and there are several ridges for the attaclunent of the lateral depressor muscles. On the occludent margin there are seYeral large oblique teeth which are not very well defined. There are several grooves n ea r the occludent basal ano·le that resemble the grooves Ol' crests which serve for the attachment of the depressor muscles to the ter·gum. 'fhese are near the basal margin and constitute one of the distinguishing marks of the species. TERGUM : Plate II, fi gure B, numbers 3 and 4. The tergum is of a rather peculiar shape as the spur is very wide; it extends for about half the length of the basal margin and forms a continuous line with the scutal margin. The crests for the attachment of the depressor muscles are well developed and they occupy the whole basal margin from the spur to the occludent margin. The articular ridge is well developed and terminates at the middle of the spur, a little above the basal margin. 314 THE WASMANN JOURNAL OF BIOLOGY, VoL. 9, 1951

::\IANDIBLE: Plate II, figure A, number 1. Each mandible has five teeth of the usual shape and size, the two near the lower angle are small. There are two spines on the lower angle, and between them and the lowest tooth there is a brush-like row of small spines that appears similar to the row of spines on the margin of the mandible of barnacles belonging to the genus Chtha.malus.

lVIAXlLLA : Plate II, figure A, munber 4. 'l'he two spines on the upper angle are long and slender and below them there is a deep notch with some slender spines in it. Below the notch the spines are of about equal length. At the lower rounded angle there are some short spines. LABR UM: Plate II, figure A, number 2. 'l'here is a depression in the middle of the labrum, but no notch; on each side of the de­ pression there are about eight teeth set closely together. It has been found that the number and also the position of the teeth varies slightly. The labrum of this species has been compared to that of Co1·onula. diadema. (Linnaeus) but there is not the slightest resemblance between these structures in the two species. 'l'he labrum of C. diadema. is shown in plate II, figure A, number 3 for comparison.

PLATE II

Figure A. Tet1·aclita squamosa ntbescens Darwin: 1, mandible; 2, labrum; 3, labrum of Co1·onula cliadema for comparison; 4, maxilla; 5 median segment of cirrus vi.

Figure B. Tetraclita sq~tamosa ntbescens: 1, interior of scutum; 2, ex­ terior of scutum; 3, interior of tergum ; 4, exterior of te1·gum.

Figure C. T etraclita sq~tamosa elegans Darwin: 1, interior of scutum; 2, interior of tergum; 3, exterior of scutum; 4, exterior of tergum. Figure D. Tetra.clita squamosa el ega.ns: 1, median segment of cirrus vi; 2, labrum; 3, maxilla; 4, outline of outer maxilla; 5, outline of palp ; 6, mandible. Figure E. Chthamalus dalli Pilsbry: 1, tergum; 2, labrum; 3, mandible; 4, maxilla; 5, scutum; 6, shell with scuta and terga in position ; 7, median segment of cirrus vi. The scale does not apply to 1, 5 and 6. Figure F . Chthcnnalus mic1·otTetus Cornwall: 1, median segment of cirrus vi ; 2, mandible; 3 maxilla; 4, labrum ; 5 and 6, outlines of two shells to show position of orifice. THE BARNACLES OF CALIFORNIA- CORNWALL 315

FIG. 0

FIG. E FIG. F PLATE ][ 316 THE WASMANN JOURNAL OF BIOLOGY, VoL. 9, 1951

CIRRI : Plate II, figure A, number 5. The rami of the first cirrus are unequal in length; the third cirrus has the posterior ramus elongated. The median segment of cirrus vi bears four pairs of spines and there are some fine spines between them. NOTES: Specimens of this species rarely become so crowded that they become tubular or even elongated. The t~r pical shape is like a depressed cone with a very small orifice. 'l'he orifice is not increased in diameter by the growth of the radii such as occurs in many species, but must depend entirely on erosion of the top of the plates to keep the opening large enough for the protrusion of the cirri. The walls are thick and are composed of many rows of tubes. In young specimens there is only one row of tubes, but more are added until there may be ten or more rows present.

Tetraclita squamosa eleg·ans Darwin. (Plate II, figures C and D.) T etmclita sqttcmwsa el egans D AHWJ N , 1854; Prr"smn, 1916, pages 250- 258.

DJ S'l'RIBUTlO N: Intertidal zone, California coast. DJMENSJON S: Diameter about 22 mm. and about hal£ as high as wide. GENER.\L APPEARANCE: Outer layer of wall usually uneroded. Epiderm us thin, possessing delicate spines. Walls ribbed. Color white. Pilsbry states that the opercular valves in this form are like those of T. s. 1·ub escens, but those collected near Pacific Grove have valves which are quite different. The differences as described are as great as those which occur between representatives of some species but this is evidently a local variation, as Pilsbry (1916, p. 258 ) states that there are intermediate forms. ScuTUM: Plate II, figure C, numbers 1 and 3. Externally the outline of the scutum is nearly triangular. The basitergal angle is rounded, the growth ridges are not well developed, and there are no traces of longitudinal striae. Internally the adductor ridge is long, well developed, and extends from near the beak to near the basal margin where it terminates near the pits which run up THE BARNACLES OF CALIFORNIA-CORNWALL 317 from the basal angle. These triangular pits are one of the dis­ tinguishing marks of T etmclita squamosa (Bruguiere) . The artic­ ular ridge in this form is like that in specimens ofT. s. 1·ubescensj the pits for the attachment of the lateral depressor muscles are deep. The pit for the adductor muscle is shallow. There are sev­ eral large teeth on the occludent margin. TERGUM: Plate II, fi gure C, numbers 2 and 4. Externally, the lines of growth are not prominent; there is a depression from the beak running diagonally across the plate. Intemally, the crests for the attachment of the depressor muscles are irregular. The spur is wide and there appears to be a beak which does not show on the exterior of the plate. MANDIBLE: Plate II, figure D, number 6. Each possesses four teeth, and at the lower angle there is a short row of small spines resembling· that of Chthamalus.

lVIAXILLA: Plate II, fi g·tue D, number 3. There are two large spines on the angle. The notch is shallow and the lower angle is rounded. LABRUM: Plate II, figure D, number 2. No notch ; on each side of the depression there are seYeral small teeth. Cmm: Plate II, figure D, number 1. The median segment of cirrus vi bears four pairs of spines and there are no small spines between them. NoTES: In the different species of T etr-aclita there is a great difference in the development of the radii. There are no radii in either of the species and subspecies (or forms) found on the coast of California. It has been observed that those barnacles that depend on the wearing away of the top of the shell for the en­ largement of the orifice have radii poorly developed or lacking. Others that have well developed radii depend on their growth for enlarging the orifice. Almost all species of T etmclita have very thin calcareous bases; these are membranous around the edges, and when the shell is r emoved from its support the base will not come away with the shell. Thus the shell will appear to have no base, but if the place from which the shell has been removed is examined the base can be seen to have been left behind. 318 THE W ASMANN JOURNAL OF BIOLOGY, VoL. 9. 1951

KEY TO THE SPECI ES 0~ ' C ILTI1Al\[AL1: S

1. Large orifice ...... C. clalli Small slit-like orifice ...... C. ?nic1·ot1·etus

Chthamalus dalli Pilsbry. (Plate II, figure E.) Clltha.malus clctlli P IL SBn Y, 1916. CORN\1'.\LL, 1925, page 473, fi gure 1.

DISTRIB U'l'JON: Northern British Columbia to Lower California. Intertidal.

DIAGNOSIS: Large oval orifice.

DIMENSJONS: The average specimen is about 3 mm. in diameter and 2 mm. high.

GENERAL APPEARANCE: Plate II, figure E, number 6. The shell is brown and has a dark band near the base. Wall s irregularly ribbed. Orifice large, oval, in the center of the shell. The sutures between the six plates forming the wall are c l ear ]~ , mm·ked in so me, in others they can hardly be seen. The occludent margins of the cover-plates and the margins between the plates form a cross. Scu·ruM: Plate II, figure E , number 5. 'l'he scutum has a short articular ridge which extends downward for about half the width of the plate. The articular furrow is deep. The adductor· ridge is rather prominent in the part nearest the basitergal angle and the adductor pit is large although shallow. 'l'here are several irregular grooves for the attachment of the lateral depressor muscles. In the specimen fi gured there are three grooves. The plate is roughly triangular and is longer than wide. TERGUM : Plate II, fi gure E, number L The tergum is broad, being about three-quarters as high as wide. The upper margin is arched and the crests for the attachment of the depressor muscles are well developed ; they are near and project slightly beyond the margin.

1\L\ N~ IBLE: Plate II, fi gure E, number 3. Each possesses foui· large teeth and a brush-like row of small spines. Th ese are char~ acteristic of all species of Chthnmnlus. -~ Ci THE BARNACLES OF CALIFORNIA-CORNWALL 319

MAXILLA: Plate II, fi gure E , number 4. Two large spines at the upper angle; below these there is a wide deep pit; the margin bears numerous spines of equal length. LABRUM: Plate II, figure E , number 2. Not notched, but possess­ ing a V-shaped depression. There are numerous irregular teeth in the depression. CmHr: Plate II, fi gure E, number 7. 'rhe median segment of cirrus vi bears four pairs of spines. The first two cirri are short. BRANCIIJAE: The branchiae of this species are long, tapering, and end in a point. '!.'h ey are two or three times the size of the corresponding structures in specimens of the species of Ohtha­ maltts that is associated with 0 . dalli. This barnacle, 0. micTotTettts Cornwall, has remarkably small branchiae.

Chthamalus microtretus Cornwall. (Plates II and I II, figure F , plate II, figu re A, plate III.)

Chtharnalus mic1·otTetus CouNw ALI., 1937, page 252.

TYPE: Catalogue number 72458 U. S. National Museum, Wash­ ington, D. C. DJSTHIBUTION : Coast of California. High in intertidal zone.

DIMENSIONS: Variable, but smaller than 0 . dalli with which it is usually associated. GENERAL APPEARANCE: Plate II, figure F , numbers 5 and 6. The shell is very irregular in shape. The rostrolateral and lateral plates ·are usually much longer on one side than on the other, the top part of these plates forms the highest part of the shell. The lateral and rostrolateral plates on the opposite side are short and this brings the orifice well down on the side of the shell. Co lor of shell light gray with dark band near base of shell. ScuTuM : Plate III, figure A, number 2. The scutum is long· and the articular ridge projects a little beyond the tergal margin. 'l.'he peculiar pit for the attachment of the depressor muscle is one of the distinguishing marks of this species. It is very deep and extends for nearly half its length up under the lining lamina 320 THE WASMANN JOURNAL OF BIOLOGY, VoL. 9, 1951

of the interior of the cover-plate. There is considerable variation in the proportions of the scutum but usually the length is about three times the width. TERGUM: Plate III, figure A, number 1. Nearly triangular; basal margin is convexly curved, crests for depressor muscle long and prominent. Both cover-plates very thin, translucent in thinnest parts. MANDIBLE: Plate II, figure F, number 2. This resembles the mandible of C. clalli. MAXILLA : Plate II, figure P, number 3. Two large spines occur at the upper angle; below them there is a deep irregular notch which extends nearly half way down the margin; below this there is an irregular prominence, and below it another notch. There are large spin es set in this second notch. LABRUM: Plate II, figure F, number 4. This resembles the labrum in specimens of C. clalli. Usually about eight teeth are present on each side. CIRRI: Plate II, figure F , number 1. The first two are short, the third is long, and the median segment of cirrus vi bears four pairs of spines.

PLATE Ill Figure A. Chthamalus micTo·t1· etns Cornwall: 1, tergum; 2, scutum ; 3, outer maxilla; 4, palp; 7, nervous system with A, nerves running to cirri ; B, infra-oesophageal ganglion; c, supra-oesophageal ganglion ; 1, oesophageal ring; S, S, splanchnic nerves; OP, nerve running to eyes. Chthamalus dalli Pilsbry: 5, outer maxilla; 6, palp. Figure B. Balanus ca1·ios1ts (Pallas) : 1, labrum ; 2, mandible; 3, maxilla; 4, median segments of cirrus vi, on a larger scale. Figure C. Balanus caTiosus: 1, interior of scutum ; 2, extet·ior of scutum ; 3, interior of tergum; 4, exterior of tergum. Figure D. Balcmus tintinnab1tlum califoTnic1ts Pilsbry: 1, exterior of scutum; 2, interior of tergum; 3, exterior of tergum; 4, interior of scutum. Figure E. Balan·us tintinnabul1t;n califoTnic1ts: 1, mandible; 2, median segment of cirrus vi; 3, labrum, dots show positions of very small teeth; 4, maxilla. Figure F. Balanus galeatus (Linnaeus): 1, mandible; 2, maxilla; 3, labrum; 4, median segment of cirrus vi. THE BARNACLES OF CALIFORNIA-CORNWALL 321

FIG. B

FIG. 0

we ~Kr. FIG. F 3 FIG. E. PLATE :m 322 THE WASMANN JOURNAL OF BIOLOGY, VoL. 9, 1951

BR.ANCHIAE : The branchiae are quite different from those of C. dalli; they are much smaller and more pointed. NOTES: There is great variation in the shape of the shell of this species. The orifice is rarely at or near the center of the shell, and in some it cannot be seen f rom the top. At fi pt glance the shell appears to be that of a small limpet. The 'arrangement of the main nerves is shown in plate III, fi gure A, number 7.

KEY TO C ALIFORNL \ SPECIES OF B .U .ANUS 1. Membranous base ...... B. caTiosus Calcareous base ...... 2 2. Pores in radii...... B. tintinnab1tlum calitor·nicus Radii solid ...... 3 3. Shell elongated in rostro-carinal axis ...... B. galeatus Shell not elongated ...... 4 4. Pores in wall filled with white powder ...... B. glandula No white powder in pores...... 5 5. Wall striped with red ...... B. concavus 1Jacificus Walls not striped...... 6 6. Wall plates having cross-septa near top ...... B. crenatus Wall plates having no cross-septa in pores...... 7 7. Scuta distinctly striate longitudinally ...... B. aquila Scuta not striate longitudinally...... 8 8. Opercular valves white inside ...... B. flos Opercular valves buff inside ...... B. mtbilus

Balanus cariosus (Pallas). (Plate III, figures Band C.) Balanus car·ios1ts (Pallas) CoRNWALL, 1925, pages 472-476. DISTRIDUTlON: Intertidal. Western North America and Japan. DIM ENSIONS: About 48 mm. diameter, and 30 mm. in height. GENERAL APPEARANCE: Radii very narrow. Internally the shell is smooth. Toward the base the plates are roughened, first with shallow pits and then with slightly irregular ridges which cor­ respond with the septa between the pores. The walls are thick, and permeated with pores which have cross-septa. The normal color of the shell is white, when eroded it is dirty gray; when crowded, members of this species gain room by lengthening the walls of THE BAR ACLES OF CALIFORNIA-CORNWALL 323 their shell s. The basis is membranous, this being the onl y member Qf the subgenus Sentib alanus found on the coast of California.

ScuTUM: Plate III, figure C, numbers 1 and 2. Externally the scutum has irregular growth ridges and fine longit udinal striae; the lower half is covered wi th membrane; the top is usually eroded. There are from four to six rounded teeth on the occludent margin. Internally, there is a hi o-h articular ridge and the a r-ti cu­ lar fm-row extends nearly to the basal margin; the pit for the lateral depressor muscle is deep, it extends under the curved adductor ridge; there is a slight ridg·e in the center· of this pit; the basal margin is convexly curved.

T ERGUM : Plate III, fi gure C, numbers 3 and 4. The exterior of the tergum is marked with prominent growth-ridges and longi­ tudinal striae; there are three shallow furrows running· parallel to the scutal margin ; the shape is rather narrow ; the spur is ncar the scutal margin ; the basal margin on the scutal side of the spur is lower than on the carinal side and is nearly at right angles to t he spur. On the ca rinal side of the spur the basal margin forms a continuous curve with the carina! margin. The furrow to the spur is closed. Internally, there is a long articular ridge which curves over the ridge running up from the spur and terminates in the articular furrow; the spur is very long and narrow and t he crests for the attachm ent of the depressor muscles are well de­ veloped.

MANDIBLE: Plate III, fi gure B, number 2. E ach mandible has fi ve teeth; the upper two arc obtuse ; the third tooth is longer than the upper two. Upper and lower margins set with small spines.

"J!AXJLLA: Plate III, fi gure B, number 3. Th ere is a shallow notch below the two upper large spines. Below the notch thcr·e is a variabl e number of spines.

LABRUM : Plate III, fi gure B, number 1. The labrum is deeply notched. Pilsbry states that there are teeth on each side of the notch but in the many specimens examined there were none.

CmRI : Plate III, fi gure B, number 4. 'l'he first three are of nearly equal length. Cirrus vi has nine pairs of spines on the 324 THE WAS MANN JOURNAL OF BIOLOGY, VoL. 9, 1951 median segment. 'l'he number seems to vary with the size of the barnacle.

Balanus tintinnabulum californicus Pilsbry. (Plate III, figures D and E.)

Balanus tintinnabulum calijontiC1tS PILSBRY, 1916, page 65.

TYPE: Catalogue number 943a, U. S. National Museum. From San Diego, California. DISTRIBUTION: Santa Barbara to San Diego, California. Below low tide mark; also on any floating object.

DrAGNOSJS: Porous radii. Shell steepl~' conica l, with narrow white stripes on red base. DIMENF'IO:-\'S: 'l'he average specimen is about 27 mm. in diameter· and 21 mm . high. GENERAL APPEARANCE: A large barnacle of striking appearance. Orifice large. It gains room by deepening base. Base and radii are porous. SHELL: The tubes are narrow and numerous, with cross-septa. ScuTUM: Plate III, figur·e D, numbers 1 and 4. The shape is triangular, with rounded tergal margin. 'l'he growth ridges are well marked. Internally there is a short prominent articular ridge, a slight depression for the adductor muscle, but no pit for the depressor muscles. TERGUM: Plate III, figureD, numbers 2 and 3. Externally the terga are tinted with faint rose color. The growth ridges are prominent and have vertical striae; the groove extends from the beak to the end of the spur. Internally the depressor muscle crests are prominent; the articular ridge is small. MANDIBLE: Plate III, figure E , number 1. There are four teeth, the lower ones being small.

1\:J:Axn... LA : Plate III, figure E , number 4. 'l'here is a slight de­ pression below the upper large spines. 'l'he lower angle is almost square. THE BARNACLES OF CALIFORNIA-CORNWALL 325

LABRUM: Plate III, figure E, number 3. There are three small teeth on each side of the V-shaped notch. CmRr: Plate III, figure E, number 2. The first t hree are short. 'l'he median segment of cirrus vi has five pairs of slender spines.

Balanus galaetus (Lin naeus). (Plate III, figure F and plate IV, figure A.)

Balanus galaet1ts (Linnaeus), Pn.snnY , 1916, pa1~es 236- 238.

TYPE: Lost. From \Vest Indies. Dr 'TRIB UTION : South Carolina to West Indies ; Central America; southern California. On gorgonians. DrAGNOSJS: The shell is lengthened along the rostrocarinal axis. 'l'he base grows around the supporting gorgonian. The tergum has a square apex. DrMENSIOKS: The average specim en is about 22 mm. in diameter and 8 mm. high. GENERAL APPEAR.\NCE: Shell smooth. Radii broad, little sunken. Base boat-shaped; shell usually covered with the outer layer of the gor·gonian. ScuTuM: Plate IV, figure A, munber 2 . ..Articular ridge pr·omi­ nent ; no adductor ridge ; no pit for lateral depressor muscle. 'l'ERGUM: Plate IV, figure A, number 1. The shape of the tergum is one of the distinctive marks of this species as it has a peculiar square apex. The spur is short, being about half the width of the basal margin. The depressor muscle crests are very small. LABR UM: Plate III, figure F, number 3. On each side of the V-shaped notch there are two teeth. CmRI: Plate III, figure F, number 4. The first pair have rami of unequal length; the median segment of cirrus vi bears three pairs of spines. l\IANDIBLE: Plate III, figure F , number 1. Three large teeth; the surface is covered with many small spines. 326 THE WASMANN JOURNAL OF BIOLOGY, VoL. 9, 1951

l\1AXJLLA: Plate III, figure E, number 2. 'l'here is no notch be­ low the upper large spines. The margin is straight.

Balanus glandula Darwin. (Plate IV, figures B and C.)

Balam~s glcmdula Darwin, Conl'iWALL, 1925, pages 483- 484.

'l'YPE: British Musewn. DJSTRTBUTION : Intertidal; Ca lifomia to Aleutian Islands. DIMENSIONS: 'l'he average specimen is about 18 mm. in diameter and 10 mm. high. GENERAL APPEARANCE: The parietal tubes are small and filled with a white powder and there are cross-septa in them. The sheath has a broad excavation under it and this is periodicall? closed by a horizontal wall. This forms a series of cells as shown in plate IV, figure B, number 6. This barnacle becomes cylindrical wh en crowded. The great variation of the pores in examples of this species is ver~' marked as some have small regular pores while others have no tntce of them whatever. ScuTUM: Plate IV, fi gure C, numbers 1 and 2. 'fhe growth ridges are prominent. The articular furrow is deep; the articular ridge is short and prominent; the adductor pit is shallow but

PLATF. IV Figure A. Balanus galeatus (Linuaeus): 1, interior of tergum; 2, in­ terior of scutum. Figure B. Balanus gla:nclulct Darwin : 1, labrum; 2, mandible; 3, maxilla; 4, median segment of cirrus vi; 5, pectinated spine from cirrus ii, much enlarged; 6, upper portion of carina with surface filed away to show cells formed under sheath. Figure C. Balamts glandnla: 1, interior of s cutum ; 2, exterior of scutum, showing translucent area; 3, interior of ter gum; 4, exterior of tergum.

Figure D. Balam~s concavus pacificus Pilsbry: 1, labrum; 2, median segment of cirrus vi; 3, maxilla; 4, mandible. Figure E. Balanus concavtts tJa cificus: 1, interior of scutum; 2, ex­ terior of scutum; 3, interior of tergum; 4, exterior of tergum. Figure F. Balanus c1·enatus Bruguiere: 1, labrum; 2, mandible; 3, maxilla; 4, median segment of cirrus vi. THE BARNACLES OF CALIFORNIA- CORNWALL 327

FIG. B

FIG . C

FIG . D

FIG. E FIG. F PLATE :m: 328 THE WASMANN JOURNAL OF BIOLOGY, VoL. 9, 1951 variable. There is a deep arched-over pit below the jtmcture of the articular and adductor ridges; this is also variable. The pit for the attachment of the lateral depressor muscle is deep and marginal. TERGUM: Plate IV, fi gure C, numbers 3 and 4. The tergum is flat and has a slight depression leading to the spur. The articular ridge and inflected scutal margin are very prominent; the articular furrow is deep. The spur is short and is nearly half the width of the basal margin ; it is placed near the basiscutal angle. 'fhe crests for the depressor muscle are well developed. The lining of the shell is black. l\fANDlBLE: Plate IV, fi gure B, number 2. The mandible has four teeth. l\fAXILLA: Plate IV, fi gure B, number 3. There is no notch under the two large spines at the upper angle. LABRUM: Plate IV, fi gure B, number 1. Ther e is an irregular number of teeth on each side of the notch. CIRRT: Plate IV, fi gure B, numbers 4 and 5. The first pair have unequal rami. The second pair are short ; the third pair are about a. third longer than the second. The median segm ent of cirrus vi has seven spines. P ENIS : The penis is long and there is a point near the base.

Balanus concavus paci.ficus Pilsbry. (Plate IV, figures D and E.) Bctla.nus concavus pacijic1ts Pn.SBI!Y , 1916, pages 104-107

TYPE : Catalogue number 32953 U. S. ~ation a. l lVIusemn, from San Diego, California. DIAGNOSIS: A conical barnacle with diamond-shaped orifice; r adii wide, slightly sunken. The shell is striped with pink on a white background; the parietal tubes lack cross-septa. The basis is thin, calcareous, and porous. DIMENSIONS: The average specimen is about 27 mm. high and 21 mm. in diameter. GENERAJ_, APPEARANCE: This species resembles Balanus tintin­ nab ~tlurn ( Linnaeus) . THE BARNACLES OF CALIFORNIA-CORNWALL 329

ScuTUM: Plate IV, figure E, numbers 1 and 2. The growth ridges are low and are crossed by striae. The color is pink near the apex, shading into white at the basal margin. Internally the articular ridge extends for about half the tergal margin. The adductor ridge is high and long, it curves across the middle of the valve nearly to the basal margin. There is no pit for the adductor muscle. 'fhe depression for the depressor muscle is deep and is bound by a thin wall which leans toward it. TERGUM: Plate IV, figure E, numbers 3 and 4. The growth ridges are prominent but possess no longitudinal striae. The wide spur is separated from the basiscutal angle by about its own width. InternaUy, the crests for the attachment of the depressor muscles are weakly developed and the articular ridge is low. MANDIBLE: P late IV, figure D, number 4. There are three large and one small tooth. lVIAXJLLA: P late IV, figure D, number 3. There is no notch under the two large spines at the upper angle. LABRUM: Plate IV, figure D, number 1. There are three conical teeth on each side of the deep notch. CIRRI: Plate IV, figure D, number 2. The first two cirri have very protuberant segments and the median segment of cirrus vi bears three pairs of spines.

Balanus crenatus Bmguiere. (Plate IV, figure F and plate V, figure A.)

Balanus cTenatus Bruguiere, COI!NWALL, 1925, pages 476-478.

TYPE LoCALITY : Coast of England. DJAGNOSJS: Shell conic, tubular when crowded. DJMENSIONS: Average about 14 mm. high, 12 mm. in diameter. DrsTRJBUTION : Arctic, Atlantic, and Pacific oceans; chiefly be- low low tide mark. South as far as Santa Barbara, California. GENERAL APPEARANCE: This is a difficult barnacle to identify, and as Darwin's original description cannot be improved it is copied in full : ' 'White, usually of a dirty tint, from the yellowish or brownish persistent epidermis; conical, generaUy with the I

330 THE WASMANN JOURNAL OF BIOLOGY, VoL. 9, 1951

parietes rugged and irregularly folded longitudinally, but some­ times much depressed and extremely smooth; often cylindrical and very rugged; occasionally club shaped, the upper part being much wider than the lower ; specimens in this latter condition sometimes have extremely narrow parietes, like mere ribs, and wide radii. The orifice in cylindrical varieties is often deeply notched. The radii are generally narrow and have jagged oblique summits. But not infrequently they are so narrow as to form mere linear borders to the compartments. 'rhe orifice is rhomboidal passing into oval, either deeply or very slightly toothed.'' SHELL: "Compartments. The internal carinal margin of each compartment from the sheath to the basis, generally, but not in­ variably, projects a little inward beyond the general internal surface of the shell in a manner not common with other species of this genus; the basal edge of this projecting margin rests on the calcareous basis and is crenulated like the basal edge of the longitudinal parietal septa. The internal surface of the shell is ribbed, but the ribs are not very prominent. The parietal tubes are large and are crossed in the upper part and often low clown by thin transverse septa; the longitudinal parietal septa are only slightly denticulated at their bases ; occasionally they divide at the basis close to the outer lamina of the parietes making some short outer subordinate pores. In the circular furrow beneath the

PLATE V

Figure A. Balanus cr·enatus Bruguiere: 1, exterior of tergum ; 2, ex­ terior of scutum; 3, interior of scutum; 4, interior of tergum. Figure B. Balanus aq·uila Pilsbry: 1, labrum-the two teeth on each side of the notch are too small to show in the drawing and are indicated by dots; 2, mandible; 3, maxilla; 4, cirrus i ; 5, median segment of cirrus vi; 6, end of pectinated spine from cirrus iii. Figure C. Balanus aquila: 1, interior of tergum; 2, exterior of tergum ; 3, interior of scutum; 4, exterior of scutum. Figure D. Bctlantts flos Pilsbry: 1, labrum; 2, mandible; 3, first cirrus; 4, shell; 5, maxilla; 6, 17th segment of cirrus vi. All after Pilsbry. Figure E . Balantts flos: 1, interior of tergum; 2, interior of scutum; 3, exterior of tergum; 4, exterior of scutum. All after Pilsbry. Figure F. Balanus nubilw; Darwin: 1, suture between wall and basis; 2, mandible; 3, maxilla; 4, part of pattern in suture between wall-plates -highly magnified; 5, labrum; 6, median segment of cirrus vi. THE BARNACLES OF CALIFORNIA- CORNWALL 331

FIG. D FIG. C ~ ~~ Lz~lv ~~ I ;_____}- "' FIG. F PLATE Jt 332 THE WASMANN JOURNAL OF BIOLOGY, VoL. 9, 1951

lower edge of the sheath ther e are sometimes little ridges dividing it into small cells; sometimes, however , this furrow is fill ed up by irregular knobs of calcareous matter. 'l'he radii are always rather narrow, and often they form mer e linear ribbons of nearly uniform width along the edge of the compartments. Their sum­ mits or edges are always more or less irregular and jagged, they form an angle with the horizon of generally above forty degrees. Their septa are fine, and barely or not at all denticulated. The alae have oblique summits ; their sutural edges are rather thick and distinctly crenated. Basis flat, calcareous, very thin, with the surface slightly marked by r adiating· furrows answering to the radiating pores that occur in the basis of most species. '' ScUTUM: Plate V, figure A, numbers 2 and 3. The lines of growth are not very prominent and sometimes there is a thin membrane which may be partly disintegrated. When the cover­ plates are in position the beaks of the two scuta project as two small flattened points. Internally, the articular ridge is well de­ veloped but ther e is no adductor ridge. There is a distinct, but shallow, impression for the attachment of the adductor muscle, and the depression for the lateral depressor muscle is small and variable. TER.GU M: Plate V, fi gure A, numbers 1 and 4. The g-rowth ridges are not prominent ; there is a faint longitudinal depression the same width as the spur, which is wide and short. The spur is about its own width from the basiscutal angle. Internally, the upper part of the articular ridge is well developed ; the crests for the depressor muscles are numerous, but variable. l\IANDIBLE: Plate IV, fi g·ure F , number 2. Ther e are three large and one small tooth. '!'her e are small spines on the lower margin. MAXILLA: Plate IV, figure F, number 3. There is a small notch under the two large spines at the upper angle. The lower angle is rounded. LABRUM: Plate IV, figure F , number 1. A deep V-shaped notch, usually with two teeth on each side.

C JRRr: Plate IV, figure F, number 4. The first pair have rami of very unequal length. The second have about three more seg­ ments than the shorter ramus of the first, and the third have a THE BARNACLES OF CALIFORNIA-cORNWALL 333 few more than the second. The median segment of the sixth cirrus has about five spines. NoTE: This species has been dredged from 250 fathoms off Santa Cruz.

Balanus aquila Pilsbry. (Plate V, figures B and C.) Balanus aquila PJLSBRY, 1916, pages 127-131.

TYPE: Catalogue number 32403, U. S. National lVIuseum. DISTRIBUTION: Monterey Bay to San Diego, California. Rarely above low tide mark. DIMENSIONS: Average specimens are about 55 mm. high and 35 mm. in diameter. DIAGNOSIS: Walls with well developed ribs. Radii with sloping tops. Interior of valves yellow. Parietal tubes with no cross-septa. GENERA L APPEARANCE: The compartments are thick and strong, and have well developed ribs. The sheath is long and there are deep hollows under its dependent edge. The radii are deeply sunken and the tops are horizontal if not worn and sometimes they have minute pores. ScuTUM : Plate V, figure C, numbers 3 and 4. The width of the scutum is less than half the length ; the exterior is convex be­ tween the occludent and tergal margins. There is a light brown or yellowish epidermis; tmder this the valve is white. The growth ridges are well developed and they are cut into beads by the longitudinal grooves which radiate from the beak. The tergal margin is short, being about half the length of the occludent mar­ gin. Internally the valve is light yellow ; the articular ridge is about two-thirds the length of the tergal margin, and is truncate at the lower end. The adductor ridge is straight and well de­ veloped. TERGUM: P late V, figure C, numbers 1 and 2. 'l'he spur is long and narrow, and is separated from the basiscutal angle by nearly its own width, and extends up on the interior surface of the valve as a low ridge which cur·ves toward the scutal margin; the articular ridge extends from the beak down on the upper part of this ridge 334 THE WASMANN JOURNAL OF BIOLOGY, VoL. 9, 1951

and terminates on the occludent side of it. The crests for the de­ pressor muscle are not prominent. Externally, there are fin e · growth ridges crossed by still :finer longitudinal grooves; the longitudinal furrow is closed. lVL\NDIBLE: Plate V, :figure B, number 2. '!'here are four teeth; the lower angle is rounded . .MAXILLA: Plate V, fi gure B, number 3. There is no notch be­ low the two large spines at the upper angle; eight to twelve spines are located on the margin. LABRUM: Plate V, :figure B, number 1. There are two small teeth on each side of the deep notch. CJRRI: Plate V, figure B, numbers 4 and 5. The first cirrus has unequal rami; the second has nearly equal rami, and the third has rami but little longer than those of the second. 'l'he third cirrus has some pectinated spines each of which has a peculiar hook at the end (plate V, :figure B, number 6). The median seg­ ment of cirrus vi bears :five pairs of spines.

Balanus flos Pilsbry. (Plate V , figures D and E .) Ba,lanus flos PrLssnv, 1916, pages 135- 138.

TYPE: Catalogue number 32405, U. S. National Museum, Alba- tross station 4558. DI STRIBUTION : Surface to 338 fathoms, California coast. DIAGNOSIS: Flaring orifice; walls faintly pink.

GENERAL APPEA.RA.!~CE: Plate V, :figure D, number 4. The basis and wall plates are porous; the radii are solid. The apices of the parietes project above the orifice which is nearly as large as the basis. Interior of the parietes is longitudinally grooved below the sheath. ScuTUM : Plate V, :figure E , numbers 2 and 4. The scutum is triangular, with a curved basal margin. Externally, the growth ridges are not prominent; there are faint longitudinal striations that can only be seen with a lens. Internally, the articular ridge is very small and lo\v ; there is a small adductor ridge ; and there THE BARNACLES OF CALIFORNIA-CORNWALL 33& are no pits for the attachment of either the adductor or the lateral depressor muscles. TERGUM: Plate V, figure E , numbers 1 and 3. Externally, the growth ridges are faint, and there is a shallow irregular longi­ tudinal striation. Internally, the spur is short and wide and is near the center of the basal margin; it curves slightly toward the scutal margin. 'rhere is no furrow to the spnr. Internally there is a strong articular ridge which crosses the ridge running up from the spur. The articular furrow is very shallow and the crests for the depressor muscles are small but numerous. l\IANDIBLE: Plate V, fi gure D, number 2. There are three small teeth ; spines are present on upper and lower margins. MAXILLA: Plate V, fi gureD, number 5. There is no notch under the two large spines. Cmnr: Plate V, fi gure D, numbers 3 and 6. 'fhe first cirri haye unequal rami. The median segment of cirrus vi bears fiv e pairs of spines, the lower pair being small. Near the upper margins of the segments there are several small short spines.

Balanus nubilus Darwin. (Plate V, figure F and plate VI, figure A.)

Balanus nttbil1~s Darwin, PILSBRY , 1916, page 131.

TYPE: British Museum, from Monterey Bay, California. DISTRIBUTION: North American coast; intertidal to 30 fathoms_ DIAGNOSIS: Interior of operm:tlar valves buff ; a vertical purple streak on interior of ter·gum. DIMENSIONS: A large barnacle, some specimens are 100 mm .. or more, in diameter, and of equal height. GENERAJJ APPEARANCE: Shell conical, with oval orifice. The shell is usually much eroded. The radii are narrow, with oblique summits. BAST S: The basis is imperfectly porous, and is thin at the center_ Room is gained by deepening the base. 336 THE W ASMANN JOURNAL OF BIOLOGY, VoL. 9, 1951

Scu'l'UM : Plate VI, figure A, numbers 2 and 3. The lines of growth ar·e prominent. Internally, the articular ridge is not well developed; the adductor ridge is prominent, produced downward, and makes a cavity for the depressor muscle. TERGUM: Plate VI, figure A, numbers 1 and 4. The apex is elongated into a beak which in old specimens is very prominent. The articular ridge is prominent; the basal margin slopes down on both sides of the spur; crests for the depressor muscle are numerous.

l\'[ANDJBLE: Plate V, figure F , number 2. There are three small teeth ; the lower one is variable. 1\IA... '

PLATE VI

Figure A. Balanus nubihts Darwin: 1, interior of tergum; 2, interior of scutum; 3, exterior of scutum; 4, exterior of tergmn. All four draw­ ings are made to the same scale. Figure B. pacifica Pilsbry: 1, mandible ; 2, maxilla; 3, end seg­ ments of cirrus vi. Figure C. Mitellct polyments (Sowerby): 1, outline of labrum; 2, part of labrum from A to B in number 1 enlarged to show teeth; 3, mandible ; 4, maxilla; 5, three types of spines from cirrus ii; 6, median segments of cirrus vi. Figure D. Lepcts tasGicula1·is Ellis & Solander: 1, labrum~ 2, small portion of margin of labrum between A and B of number 1 highly magni­ fied to show teeth ; 3, mandible ; 4, maxilla; 5, median segments of cirrus vi; 6, specimen attached to float. Scale does not apply to number 6. Figure E. Lepas anatije1·a Linnaeus: 1, mandible; 2, first cirrus from the left side with filamentary appendage (A) attached and second ap- _ pendage (B) from near base of cirrus; 3, maxilla; 4, median segment of cirrus vi; 5, palp from left side. Figure F. Scalpell1trn calijon1.i cwm Pilsbry: 1, maxilla; 2, rostrum, very much enlarged; 3, mandible; 4, capitulum and pa1·t of peduncle; 5, media n segm e nt of cirrus vi; 6, palp. THE BARNACLES OF CALIFORNIA---C ORNWALL 337

. 0 . FIG. A

I M M.

FIG. D

FIG. C

FIG. E FIG. F PLATE J!I 338 THE WASMANN JOURNAL OF BIOLOGY, VoL. 9, 1951

CmR.I: Plate V, figure F, number 6. 'l'he first cirrus has very unequal rami, 33 and 18 in one specimen; the second cirrus has nearly e rual rami; cirrus vi bears six pairs of spines on the median segment.

SHELL: Small specimens are strongly ribbed, but it is rare to find a large one that shows the true form of the shell. In the col­ lection of the Hopkins Marine Station there is one that is llO mm. in diameter and 75 mm. high. The sutures between the wall p lates are marked by a wide area of denticulation which increases in extent as the barnacle grows. A small portion of this denticulation is shown (highly magnified) in plate V, fi gure 1<", number 4

Alepas pacifica Pilsbry. (Plate VII, figure A and plate VI, figure B.)

Ale1Jas pacifica PILSBRY, 1907, page 105.

TYPE: Catalogue number 28797, U. S. National Museum. DIAGNOSIS: Attached to medusa. Capitulmn without valves. Mandible with six teeth. GENERAL APPEARANCE: Plate VII, figure A. Capitulum with a straight orifice; the carinal margin is arched. The peduncle is shorter than the capitulum and is not, as in some species, separated from it by a distinct line. The color is a uniform dirty white. ScuTUM: The scutum is very small and is composed of trans­ lucent horny matter. TERGUM : None. MANDIBLE: Plate VI, fi gure B, munber 1. The lower of the six teeth appears to be pectinated. MAXILLA: Plate VI, fi gure B, number 2. Beneath the upper large spines there is a notch ; the margin forms three irregular steps. CIRRI: Plate VI, fi gure B, number 3. The first cirri are short and the rest are of nearly equal length. THE BARNACLES OF CALIFORNIA-CORNWALL 339

Mitella polymerus (Sowerby). (Plate VII, figure Band plate VI, figure C.) llfitella 11olynten1s (Sower by) , ConN wALL, 1925, pages 486- 489.

D ISTRIBUTION: Pacific coast of North America; also south Pa­ cific Ocean. In intertidal zone only.

DIAGNOSIS: The only pedunculated barnacle found in the inter­ tidal zone on the North American coast.

GENERAL APPEARANCE: Plate VII, figure B. The capitulum has several whorls of valves which decrease in size from above down­ ward. In the lowest of these whorls there are some eighty or ninety valves. The valves are not of equal size; their sur·face is usually much disintgratcd. 'l'he membrane connecting the valves is dark.

PEDUNCLE : Plate VII, figure B. The upper part of the peduncle is less in diameter than the capitulum and it tapers a little down­ ward ; it is covered with small calcareous scales.

FrLAMEN'fARY APPENDAGES: 'l'hese are placed in two rows on the under side of the prosoma; there are twelve on each side. On the end of each appendage there arc about six minute spines. There is another short appendage attached to the prosoma be­ neath the pechmcle of cirrus i ; its free end lies between the peduncles of i and ii. In the base of this appendage there is a hard transparent disc. The number of the appendages varies ·with the size of the barnacle.

CAU DAL APPENDAGES: 'l'hey have two segments and are short.

Scu•ruM: These are nearly oval. TERGUM : About the same length as the scutum; the interior is concave. l\IANDIDLE: Plate VI, figure C, munber 3. 'l'here are three large teeth; the lower angle is very protuberant and is covered with spines. l\IAXILLA: P late VI, figure C, number 4. A notch under the two large spines at the upper angle. At the middle of the margin 340 THE WASMANN JOURNAL OF BIOLOGY, VoL. 9, 1951

there is a tuft of fine spines ; another tuft is present at the lower angle. LABRUM: Plate VI, figure C, numbers 1 and 2. 'l'he labrum is bullate and there is no notch. There are many irregular fine teeth set in the level part between A and B, as shown in number 1 of this figure C. 'l'his area is shown much enlarged in number 2 of this same figure. CIRRI: Plate VI, figure C, numbers 5 and 6. The first cirrus has protuberant segments and usually bears three kinds of spines as shown in m1mber 5 of this figure. The median segm ent of cirris Yi bears seven spines.

KEY TO SPECIES OF LEPA S 1. Attached to float formed by base ...... Le1Jas tasci culaTis Attached to some floating object...... 2 2. Two filamentary appendages; right umbonal tooth larger than left ...... Lepas anatitem Three filamentary appendages; no umbonal tooth ...... Lepas hi llii (Leach)

Lepas fascicularis Ellis and Solander. (Plate VI, figure D and plate VII, figure C.) L epas tasci culm·is Ellis and Solander. PrLSBRY , 1907, page 81.

DISTRIBUTION: Northern Pacific and Atlantic.

DIAGK o s rs : A pedunculate barnacle that forms its own float.

Pun: VII Figure A. A l epas 1Jacifica Pilsbry: specimen taken from the , PhacellopoTa. Figure B. Mit ella 1JOlymen ts (Sower by) : four specimens collected near Pacific Grove, California. Figure C. L epas tasci culcwis Ellis & So lander: three specimens at· tached to the float. Figure D. Lepas anatite1·a. Linnaeus. Figure E. Scal1J ellmn osse•ttm Pilsbry: 1, mandible; 2, palp ; 3, labrum; 4, maxilla; 5, median segment of cinus vi. Figu1·e F . Scalpellum osseum: 1, plates covering capitulum and show· ing umbones ; 2, rostrum much enlarged; 3, capitulum and portion of peduncle. THE BARNACLES OF CALIFORNIA-CORNWALL 341

FIG. B

FIG. E Fl G. F

PLATE JZII 342 THE WASMANN JOURNAL OF BIOLOGY, VoL. 9, 1951

GENE I~AL APPEARANCE: Plate VII, figure C. The fiv e plates forming the capitulwn are very thin and paper-like; the peduncle is very short; several barnacles arc usually attached to the same float. 'l'he float is composed of a vascicular stmctureless mem­ brane. This float is formed by a singular development of the cement tissue which ordinarily serves to attach the cirripede to some object. The young free-swimming cirripede first attaches itself to some small floating object and around this it builds the float. 'l'he color of those taken in the North Pacific is usually dirty white, or some shade of purple, but there is considerable variation in color. ScuTUM: P late VI, fi gureD, number 6S. 'l'he tergocarinal mar­ gin is very protuberant; the occludent margin slightly reflexed. TEtWUM : Plate VI, figureD, number 6'1'. Flat, with the occludent margin arched. 'l'his valve is variable in shape. CA RJNA: Plate VI, figure D, number 6C. 'l'he carina is highly variable in shape. MANDIBLE: P late VI, figure D, number 3. Each mandible has fiv e large teeth ; the inferior angle is rounded and pectinated. The lower part of each tooth has a row of very small sharp teeth. MAXILLA: Plate VI, figureD, number -!. Below the two large spines at the upper angle the margin forms three irregular steps. LABRUM: Plate VI, figure D, numbers 1 and 2. In the center of the depression there are many conical teeth, shown enlarged in number 2 of this figur·e. CIRRI: P late VI, figure D, number 5. 'I.' he first haYe slightly protuberant segments. There are man.'' spines on the sixth cirrus. FILAMEN'rARY APPENDAGES: There are three of these at the base of the first cirrus, and one on the flank of the prosoma. CAUDAL APPENDAGES: These are smooth, unseg·mented, and haYe rotmdcd tops.

Lepas anatifera Linnaeus. (Plate VII, figure D and plate VI, figu r e E.) (Figures 32, 33.)

L e]Jas anatifeTa Linnaeus. C. A. Nn.sso!\"-CANTELL, 1928, page 13. THE BARNACLES OF CALIFORNIA-CORNWALL 343

TYPE: Lost.

DrsTRIB TION : Mundane. On floating· objects. DIAGNOSI : Never· more than two filamentary appendages on each side, sometimes one, and occasionally none. 'fhe umbonal tooth on the occludent basal angle o£ the scutum is usuall y larger on the right than on the left. GENERAL APPEARANCE: Plate VII, fi gure D. 'fhe plates on the capitulum usually are white or bluish gray. Scu·ruM: Plate VII, fi gure D. The umbones are at the angle formed at the juncture of the occludent and the basal margins. There may be a row o£ quadralateral depressions extending across the valve; these are very variable in size. TERGUM: Plate VII, figure D. The umbones are at the top angle. CAHINA: Plate VII, figure D . This plate varies greatly in shape but usually extends above the middle of the tergum. FILAMENTARY APPENDAGES: Plate VI, fi gure E, number 2AB. The number o£ filamentary appendages is the best characteristic £or distinguishing this species £rom L epas hilli which it closely resembles. It has never mo·re than two appendages on each side, some have only one, and others none. MANDIBLE: Plate VI, figure E, number 1. There are five sharp teeth and the lower angle is pointed. MAXILLA: Plate VI, figure E, munber 3. There is a notch belo·w the two upper great spines. LABRUM : The labrum is bullate and has many small teeth in the central depression and on each side o£ it. CIRRI: Plate VI, figure E , numbers 2 and 4. The median . eg­ ment of cirrus vi bears six pairs of spines.

KEY TO SPECIES OF S CALPELLUM

1. Valves marked with purplish patches ...... S. calijontiC1t?n No purple patches on valves ...... S. osseum. 344 T HE WASMANN JOURNAL OF BIOLOGY, VoL. 9, 1951

Scalpellum californicum P ilsbry. (Plate VI, figure F .) ScaltJ ellmn ca.lifonticunt PJLSBnY, 1907, pages 195- 196.

TYPE : Catalogue number 32811, U. S. National Museum. DIS'l'RIBUTION: Monterey Bay, California. DIAGNOSIS: 'l'hick epidermis almost obscuring valves. GENERAL APPEA RA NCE: Plate VI, figure F , numbers 2 and 4. Fourteen plates; the rostrum, number 2 of this fi gure, is almost square in outline. PEDUNCLE: P late VI, figure F , number 4. The peduncle is cov­ ered with lozenge-shaped scales. ScuTUM: Plate VI, fi gure F , number 4. The greatest length of the scutum is the occludent margin. TERGUM : Plate VI, fi gure F , number 4. The tergum is long and projects slightly beyond the occludent margin ; the basal margin is straight ; the carinal margin is curved. CAlUNA: Plate VI, fi gure F , number 4. The carina is evenly cun-ed and extends above the center of the tergtml. The umbo is apical. UPPER LATUS : Plate VI, fi gure F , number 4. Its width is greater than its height. The umbo is at the upper scutal angle. RosTRO-LATUS : Plate VI, fi gure F , number 4. This plate is small and wedge-shaped, and its point does not project beyond the occludent margin. I NFRAMEDIAN LATUS : Plate VI, fi gure F , number 4. The plate is nearly square in outline and the umbo is near the center. CARI NO-LATUS : Plate VI , fi gure F , number 4. Small er than inframedian latus; the umbo is at the point that projects under the carina. MANDIBLE: Plate VI, fi gure F , number 3. There are three large teeth. MAXILLA: Plate VI, fi gure F , munber 1. There is no notch under the two large spines at upper angle; the lower angle is nearly square. THE BARNACLES OF CALIFORNIA-CORNWALL 345

LABRUM: Plate VI, figure F, number 3. It is the same as that of Scalpellum osseum. CIRRI: Plate VI, figure F, number 5. The median segment of cirrus vi bears three pairs of nearly equal spines; there are a few small spines between them. Th e names and position of the plates of Scalpellmn are shown in plate VII, figure F.

Scalpellum osseum Pilsbry. (Plate VII, figures E and F.) Scctlpellmn osseum P ILSBUY , 1907, pages 19- 20. TYPE: Catalogue number 32413 U. S. National Museum. DISTRIBUTION: Off the coast of California in about 80 fathoms. DIAGNOSIS: The outline of the valves can be clearly seen through the membrane. 'l'he occludent margin is nearly a straight line. There is no colored area on the valves. GENERAL APPEARAN CE: Plate VII, fi gure F, number 3. The lines of growth on the 14 plates are faint but the umbones can be seen through the thin membrane. The tergum does not project beyond the margin. PEDUNCLE: Plate VII, figure F, munber 3. The scales on the peduncle are smaller than those on S. californicum. ScUTUM : Plate VII, figure F , number 3S. The occludent and lateral margins are parallel and the umbo is near the upper angle. TERG UM : P late VII, fi gure F , number 1T. The umbo is at the upper angle. RosTRUM: Plate VII, figure F , munber 2R. Shown enlarged. The umbo is at the margin nearest the orifice. CARlNA: Plate VII, fi gure F, number 1C. The carina is weakly curved and its upper end is near the center of the tergum. UPPER LATUS : Plate VII, fi gure F , number 1UL. The two upper angles of this plate are nearly square. 'l'he lower margin is rounded ; the umbo is near the upper scutal margin. RoSTRO-LATUS: P late VII, fi gure F , number 1RL. The umbo is at the middle of upper margin. 346 THE W ASMANN JOURNAL OF BIOLOGY, VoL. 9, 1951

lNFRAMEDIAN LATUS: Plate VII, figure F , number liL. This plate is more or less rounded; it is slightly variable on the two sides of one specimen; the umbo is near the center. CARINA-LATUS: Plate VII, figure F, number l CL. Irregularly triangular. The umbo is near the lower angle. MAl'

LITERATURE CITED CORNWALL, I. E. 1925. A review of the Cirripedia of the coast of British Columbia, with glossary, and key to genera and species. Contributions to Canadian Biology, new series, 2:471-502. 1937. A new species of barnacle from the coast of California. Annals and Magazine of Natural History, series 10, 20:232-235.

DARWIN, CHARLES 1851. A monograph on the sub-class Cirripedia, The Lepadidae. xi+400. The Ray Society, London. 1854. A monograph on the sub-class Cirripedia. The Balanidae, etc. viii +684. The Ray Society, London.

NILSSON- C ANTELL , C. A. 1928 Studies on cirripeds in the British Museum (Natural History). Annals and Magazine of Natural History, series 10, 2:1-39.

PILSBRY, HENRY A. 1907. The barnacles (Cirripedia) contained in t he collections of the United States National Museum. United States National Museum Bulletin, 60:1-122. 1916. The sessile barnacles (Cirripedia) contained in the collections of the United States National Museum; including a mono­ graph of the American species. United States Natjonal Museum Bulletin, 93 :1-366.