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Full text of "Catalogue of the collection of Mazatlan shells in the British Museum, collected by Frederick Reigen"

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http://www.archive.org/details/catalogueofmazatOObrituoft 



o"\Ausc^a 



CATALOGUE 



OP THE COLLECnOlT OB 



MAZATLAN SHELLS, 



BRITISH MUSEUM: 



COLLECTED Br 

FEEDERICK EEIGEK 



DKSCKIBKD BT 



r H I L I P P . C A K P E ?: T L li 



LONDON: y\ 

I'RINTKU BY ORDER OF THK IKUSTKES. 

1857: 



PBINTkD BV P. r. CABI'£>'ThK, OBBKLIN TUESS, W ABKIIIGTOX. 



PREFACE. 

"The Collection, from which the shells described in the 
following pages have been carefully selected, was made at 
Mazatlan, {lat. 23" N., long. 107° W.) during the years 184S-50, 
by a Belgian gentleman named Frederick Eeigen." The buUi 
of that portion of it quoted in the following pages as the 'Liver- 
pool Collection,' was purchased by Herbert Thomas, Esq., of 
Bristol, and Mr. P. P. Carpenter. The latter gentleman 
"selected from it as many specimens as might be required 
(1) to illustrate the local-fauna of a known station at the 
mouth of the Gulf of California ; and (2) to exhibit the 
amount of variation, whether great or little, observed in com- 
paring together large nxmibers of individuals in the various 
species. The latter object appeared of no slight importance, 
especially for the sake of inland naturalists ; who have usually 
to depend on the very limited number of specimens which are 
generally to be seen both in public and in private collections." 

This series Mr. Carpenter presented to the British Museum, 
on the understanding that it should be kept separate and 
intact for the purposes above named, like the Cuban, South 
American, and other local collections : he imdertaking, at the 
same time, to prepare a Descriptive Catalogue, which is here 
printed. The descriptions of the Brj^ozoa, occupying the 
first six pages, were kindly communicated by G. Busk, Esq. 
E. E. S., &c. 

"The collection consists of about 8873 specimens (250.5 Bi- 
valves, &c., and 6368 Univalves) mounted on 2530 glass tablets. 
The number to the left refers to the species, that to the right 
to the tablet iri the Catalogue. The minute specimens are 
fastened on strips of thin glass enclosed in test tubes. By this 
mode of arrangement, both sides of the object can be seen 
without disturbance." 

"The measurements (unless otlxemise expressed) are thus 
taken. In the bivalves ; lotig. from the umbo to the middle 
of the ventral margin ; lat. from the anterior to the posterior 
ends ; alt. the thickness of the closed valves. In the spiral 
u nivalves ; long, from the vertex to the base ; long. spir. from 



PEEFACE 



the vertex to the posterior end of the labrum ; lat. the diame- 
ter of the body whirl ; div. the mean angle of divergence of 
the spire outlines. ALL the measurements of length are given 
in inches and decimal portions." 

"In describing the sculpture of bivalves, cowcere^ric signifies, 
in the direction of layers of growth ; radiating, from the 
lunbo to the margin. In the spiral univalves; radiating 
(from the axis of the sheU), in the direction of layers of growth ; 
spiral, along the whirl, parallel to the suture. In comparing 
the words used to describe sculpture (lirfe, lirulse, sti-iae, striuls, 
&c.) with the same words in other books, they should often be 
interpreted as to the appearance of the shell under the micro- 
scope, generally with an inch-achromatic. The vertex appHes to 
the whole nuclear portion ; but the apex only to the first whirl. 
As a slight twist in this may, or may not, be estimated as a 
whole turn, the number of whirls, as stated by different authors 
for the same shell, may sometimes vary."* 

"The terms expressing frequency are generally used as 
follows : extremely rare, under a score ; very rare, under 100 : 
rare, under 200; not common or not uncommon, 'BOO ; common, 
up to 400 or 500; abundant, about 600 or 700: extremely 
common, up to 1,000 ; extremely abundant, more than 1,000." 

"In citing geographical authorites, the name of the first 
observer is distinguished by Italics. The mark of uncertainty 
[?], is to be understood as always referring to what follows, 
and not to the word going before." 

"An estimate of the value of the Reigen Collection as a 
geographical authority, and a comparison of it with other 
neighbouring faunas, wUl be found in the 'Eeport of the pre- 
sent state of our knowledge of the Molluscaof the West Coast 
of N.America,' presented to the Britisli Association in Sept. 
1856, and published in its Transactions, pp. 159—368." 

JOHN EDWARD GRAY. 

British Museum .- April 22nd, 1857. 

•"This may account for diacrppancies in YitrineUa, and in the d|=s^^P''°°* 
of the nuclear vertex in Pyramide&dte. In this Catalogue, the number is orer 
rather than under-rated." 



CONTENTS. 



PAGE. 
CLASS BRYOZOA. (Species 1-13, 677-679.) 

OEDER INFUNDIBULATA. 

SuBOEDEE CHEILOSTOMATA. 

MEMBEANiPOEiDiE. {Tablets 1 — 13.) 

Membranipora ... ... 1 

Lepralia ... ... 3, 6, 529 

CELLEPOEiDiE {Tablets 14 — 16.) 

Cellepora ... ... 5, 6 

SuBOEDEE CYCLOSTOMATA. 

TUBULIPORID.1:. 

Tubulipora ... ... 6 

DiscoPOEAD.aE {Tablets 17, 680.) 

Defrancia ... ... 6 

CLASS TUNICATA 7 

CLASS PALLIOBRANCHIATA. {Species 14.) 

DisciNiDiE {Tablets 18—20.) 

Discina ... ... 7 

CLASS LAMELLIBRANCHIATA. {Species 15-220, 

680-691, 693, 694.) 

Pholadidje. {Tablets 21—42.) 

Pholadidea ... ... 8 

Parapholas ... ... 9 

Martesia ... ... 13 

GASTEOCH.SNiDiE. {Tablets 43-59.) 

Gastrochsena ... ... 14, 547 

Saxicavidje. {Tablets 60—64.) 

Saxicava ... ... 1(5 

Peteicolid^. {Tablets 65—74, 781, 2516.) 
Petricola ... ... 17,547 

Hupellaria (Venerupis) 20 

Naranio ... ... 169,-529 

MYiDas. {Tablet 2517.) 

Mya ... .,, 52«) 

CoBBUliD^. {Tablets 75—82, 2518—2520.) 
Corbula ... ... 21,530,547 

Sphsenia ... ... 24,530 



X- CONTENTS 

(Lamellibranchiata, cont.) page. 

'Pandobid^. {Tablets 83—85, 2528.) 

Lyonsia ... 26,530,548 

lyleria ... ... 25,547 

SoLECUETiDiE. {Tablets 86—90.) 

Solecurtus ... ... 27 

TELLiNiDiE. {Tablets 92—131, 2521.) 

Semele (A7npkidesmaJ ... 28,548 

Cmningia ... ... 29 

Sanguinolaria ... 31,548 

Tellina ... ... 32,531 

Tellidora ... ... 39,548 

Strigilla ... ... 39 

DoNACiD^. {Tablets 132—210.) 

Ipliigenia (Capsa) ... 42, 548 

Donax ... ... 43,548 

Macteid^. {Tablets 211—215.) 

Mactra ... ... 50,548 

Spisula ... ... 51 

Mulinia ... ... 52,549 

Gnathodon (Bangia) ... 52, 549 

Venerid^. {Tablets 216—411.) 

Clementia ... ... 54 

Trigona ... ... 54,549 

Dosiuia (Artemis) ... 60 

Cyclina ... ... 62 

Diono ... ... 63 

C.ytherea ... ... 70 

Venus (Chione) ... ... 71,549 

Tapes ... ... 76 

Anomalocardia ... ... 78 

AsTARTiDJi:. {Tahlets 'i\2—42A.) 

Circe ... ... 81 

. Gouldia ... ... 82,549 

Cardita ... ... 84 

Venericai'dia ... ... 85 

Trapezium (Cypricardia) ... 86 

Chamid.*;. {Tablets 425 — 445.) 

,'^:' Chama ... ... 87,549 

CAEDiADiE. {Tablets 446—463, 2522.) 

Cardium ... ... 90,531 

Lucinid;e. {Tablets 464—478. ) 

Liiciua ... ... 96 

Fimbria (Corbis) ... 101 



CONTENTS Xi. 

Lamellibranchiata, cont.) t,.-.^ 

PAGE, 

DiPLODONTiD^, [Tablets 479—484.) 

Diplodonta ... ... 102,549 

Felama ... .. iqS, 549 

Kelliad^. {Tablets 485—504, 2523, 2529 ) 
f^^^^ ■■■ ... 105 

^^^^^^ - ... 107,531,549 

-Lepton ... jiQ 

Pytliina ... 222 

Montacuta ... 222 531 

Ctcladid^. (Tablets 505— 522.) 

Cyrena ... 214 

Unionidjj. (Tablets 523—527.) 

Anodonta ... 217 550 

MYTILID.E. (Tablets 528—607, 2530.) 

Mytilus ... 218 

Septifer ... 220 

Modiola ... 220 

Crenella ... .. '" 223 550 

Litliophagus (lAthodomus) ... "' ' 124 
Leiosolenus iQn ccr) 

Arcade. (Tai/e^* 608-666,' 2524 ) 

™ •■• 132,532,550 

xjyssoarca 238 

Pectimculus . . 244 

NucxJLiD.'E. (Tablets m,ms.) 
Nucula 
Leda 
AvicuLiDiE. (Tablets 669—690.) 

Pinna ... 24f; 

Avicula ... 24" 

Margaritiphora (Meleagrina) 149 550 

Isognomon fPemaJ ' 249 

PECTINID.E. (Tablets 091,2525,2526) 

Q ^^^^^'i ■•• ... ' 152, 532 

bPONDYLiDiE. ( TaS^e^s 692— 701.) 

Spondylus ico 

Plicatida ... ■■ |„ 

OsTEEiDiE. (Tablets 702— 7U.) 

Ostrea ... 25r -(^n 

ANOMiADiE. (Tablets 7i5— 780.) ' 

Placunauomia ... 2f54 

Anoniia '" ,f,^ 

CLASS PTEROPODA. ... ... 270 



145 
145 



Xii. CONTENTS ^^^^^ 

CLASS GASTEROPODA. (5f^m>s 221-676, 692.) 
SUBCLASS OPISTHOBRANCHIATA. [Species ^\-m,m2.) 
OKDEE TECTIBRANCHIATA. 

CYLICHNIDJ5. {TaUetsn2-1U.) 

CyHchna ... .■• J70 

Tornatina ■.• •■• •^'■'■ 

BULLID32. Tablets 785-793. 

BuUa ... - 172 

Haminea ... •■• ^' 

Philinid^. (Tablet ^27.) 

Smaragdiuella ( Glauconella) i>io 

SUBCLASS PULMONATA. (Species 22.0-2^1.) 
OEDEE GEOPHILA. (Si^mes 230-234.) 
Testacellid^. (TaUets 72^,7^0.) 

Glaudina ... •■• ^^^ 

Helicid,e. (TaiZe^s 796-811.) 

Ortlialicus (Bulimus) ... ^''^ 

OEDEE LIMNOPHILA. (Spmes 235-238.) 
AuEicTJLiDiE (Tablets m-%U) 

Melampiis (Conovuhis) ■■■ -^'^ 

LiMNEiD^. (TaiWs 815-832.) 

Aplexa (Physa) ... ■•• J^^ 

Plauorbis ... ■•• 

OEDEE THALASSOPHILA. (Si^^^f 23^241.) 
SlPHONAKiAD.i=. (Tablets mi-hbl.) 

Siplionaria •■■ •• ^ ' 

SUBCLASS PROSOBRANCHIATA. (Si^e^V. 242-676 ) 

OEDEE HETEEOPODA. (Species 2M, 2^-) 
lANxniNiBJK. (raiZeis 868-878.) 

lantliina ■■• •• ^^^' 

OKDEE LATEEIBEANCHIATA. (Species 244^247.) 

DENTALIAB.E. (TaWc/. 879-882.) ^gg 

Dentalium ... 

OEDEE SCUTIBEANCHIATA. (Species 248-329.) 

Chitonid.t.. (rc.WcV. 883-907.) ^^ 

Lopliyras ... •■ -j^gg 

J^^}*,^^, - ■■■ 194,550 

Lepiclopleurus ..• •■• ' ^g^ 

Chiton ... ••• igg 

Acanthochites 



CONTENTS XUl. 

(Gasteropoda Scutihranchiata, cont.J PAGE. 

Patellidje. {Tahlets 908— 9U.) 

PateUa ... ... 199 

Nacella ... ... 202 

AcMiEiD^. {Tablets 945—1016.) 

Acmfea (Tcdura) ... 202,550,551 

Scutellina ... ... 210 

Gadiniad.e. {Tablets 1017—1023.) 

Gadiuia ... 212 

FissuEELLiDiE. {Tablets 1024—1080.) 

Fissurella ... ... 213 

Glyphis ... ... 220,551 

. Rimula ..". ... 222 

Haliotid^. 

TEOcniDJJ. {Tablets 1081—1180.) 

Callopoma (TicrboJ ... 223 

224 
226 
227 
231, 551 
233, 551 
236 
248 
250 
250 
253 



Pliasianella 

Bankivia 

Uvanilla (Imperator) 

Troelius 

Omphalius . . . 

Vitrinella 

? Liotia 

Globulus (Rotella) 
Ethalia 

Teinostoma 
NeeitiDvE. (TaJZe^s 1181—1312.) 

Nerita ... ... 255 

Neritina ... ' ... 258,551 

ORDEE PECTINIBEANCHIATA. 

{Species 330—676.) 
Suborder EOSTEIFEEA. {Species ^Z(y~^9.) 
Vanicoridje. {Tablets 1313 — 1315.) 

Vauicoro (Narica) ... 262 

Calyptrteid.t,. {Tablets 1316—1461.) 

Trocliita ... ... 264 

Galevus ... ... 265 

Crepidula ... ... 267 

Crucibulum ... ... 286 

Calyptra>a ... ... 294 

CAPULiDiE. {Tablets 1462—1475.) 

Hipponyx ... ... 296 

Capulus ... ... 300 



XIV. CONTENTS 

(Gasteropoda Mostrifera, cont.) page. 

Veemetid^. {Tablets 1476—1513.) 

Siplionium ... ... 301 

-'^I'^tes ... ... 301 

Vermetus ... ... 303 

Bivonia ... ... ~ 305 

Petaloeonclius 308 
Cj2CID^. {Tablets \^l4i—lbbi.) 

Cax'um ... ... 312 

TuEEiTELLiDjE. {Tablets 1552—1574) 

Tim-iteEa ... ... 330,552 

CEEITHIAD.E. {Tablets 1575— 1«37.) 

Ceritliium ... ... 333 

Vertagus ... ... 339 

Triforis ... ... 340 

Cerithidea ... 342 
LiTOEiNiDji:. (Tai^ef* 1638—1703.) 

Litorim ... ... 346 

Modulus ... ... 351,552 

Fossarus ... ... 353 

Isapis ... ... 355 

KissoiD.13. {Tablets 1704—1715.) 

Eissoina ... ... 35G 

Barleeia ... ... 358,552 

Alvania ... ... 3,59 

Cingiila ... ... 360 

Hydrobia ... ... 3G0 

Jeffreysiad^. {Tablets 1716—1720.) 

JefFreysia (RissoeUa) ... 361 
Tet^ncatellid.^. {Tablet 1721.) 

Trimcatella ... ... 364 

Planaxid^e {Tablets 1722—1732.) 

Planaxis ... 3(>4 

Alaba ... ... ... 365 

OvuLiD.i-:. {Tablet inZ.) 

OviUa (Radius) ... ... 370 

Cypbjeid.e. {Tablets 1734—1812.) 

Cypnua ... ... 371 

Luponia ... ... 373 

Aricia ... ... 373 

Trivia ... ... 375 

Cancellaeiad^. {Tablets 1813—1820.) 

CauccUaria ... 380 
Stkombid.'e. {Tablets 1821-1827.) 

Strombus ... 381 



CONTENTS XV. 

(Gasteropoda Pectinibranckiata, cont.) PAGE. 

Sfboedeb TOXIFEEA. {Species 450-483.) 
Teeebeidji:. {Tablets 1828—1878, 2515.) 

Terebra ... ... 384 

Myurella ... ... 384 

Subiila ... ... 387 

Em-yta ... ... 388 

PLEiTEOTOMiDiE. {Tablets 1879—1915.) 

Pleiirotoma ... ... 390 

Drillia ... ... 392 

Clatliiirella (Defrancia) . . . 399 

Mangelia ... ... 400 

Citliara ... .. 4Q1 

CoNiDji:. {Tablets 1916—1948.) 

Conus ... .... 401 

SuBOEDEE PEOBOSCIDIFEEA. -S^pec/e? 484-676. 
SoLAEiADiE. {Tablets 1949, 1950.) 

Torinia ... 407 
Pyeamidellid^. {Tablets 1951—3027.) 

Obeliscus ... ... 409 

Odostomia ... ... 410 

Auriculina ... ... 413 

Partlienia ... ... 413 

Chrysallida ... 416 

Chemnitzia ... ... 427 

Dunkeria ... ... 433 

Eulimella ... ... 436 

Aclis ... ... 437 

Eulima ... ... 438 

Leiostraca ... 439 
Ceeithiopsid^. {Tablets 2028—2035.) 

CeritJiiopsis ... 442 
ScALAEiAD^. (jPaJ/ei;* 2036—2041.) 

Scalaria ... ... 446 

Cirsotrema ... 447 
NATiciDiE. {Tablets 2042—2061.) 

Natica ... ... 448 

Lunatia ... ... 45I 

Polinices ... ... 452 

Lamellaeiad^. {Tablets 2062, 2063.) 

Lamellaria ... ... 453 

FicuLiDiE. Fioula ... .. 453 

Teitonid^, (Tai/eifs 2064— 2072.) 

(Triton) Argobuccinum ... 454 



XVI. CONTENTS 

fGastero2}oda Proboscidifera, cont.J page. 

TuEBiNELLiDyE, {Tablets 2073—2078.) 

Turbinella ... ... 456 

Fasciolakiad*. [Tablets 2079—2090.) 

Lathirus ... ... ["4751 457 

Leucozonia ... ... [475] 457 

Fasciolaria • ... ... 458 

MiTEiN^. {Tablets 2091—2106.) 

Mitra ... . , 459 

Strigatella ... ... 461 

Maeginellid^. {Tablets 2107—2109.) 

Marginella ... ... 461 

0LIVIDJ5. {Tablets 2110—2213.) 

Oliva ... ... 463 

Olivella ... ... 467 

Agaronia ... ... 472 

PuEPUEiD^. {Tablets 2214—2309.) 

Purpura ... ... 474 

Cuma ... ... 481 

(Rapana) llliizoch.eilus 484 

Vitularia ... ... 485 

Nitidella ... ... 487 

BUCC1NIDJ5. {Tablets 2310—2365.) 

ColumbeUa ... ... 489 

Metula ... ... 493 

Nassin^. (Tai/f/s 2366—2407.) 

Nassa ... ... 494 

Pyeulid^. (r«6?e^6- 2408—2411.) 

Pyrula ... ... 500 

MuEiciDJ-. {Tablets 2^12— 2bU.) 

Fusus ... ... 502 

Cominella ... ... 505 

Anacliis ... ■ ■ 505 

Strombina... ... 513 

Pisania ... ... 513 

Murex ... ... 518 

Phyllonotus ... 521 

Milricidea . . . ... 526* 

CLASS CEPHALOPODA. 

APPENDIX. 

Philippi's Descriptions of Mazatlan Shells 534 

Menke's First List and Descriptions of do. 536 

Second do. do. 54() 

Additions and Cobbections ... 546 



CATALOGUE 

of' 

MAZATLAN MOLLUSCA. 



CLASS BRYOZOA. Ehr. 

Bbtozoa; Ehrenherg, Corall. ties Both. Meeres, 15d.— Jones An. 
Kingd. 107— 117.— 0;ye« Led. 9$—lOl.—Audouiii ^ Milne- 
Edwards in Lam. An. s. Vert. ii. 104, 2de ed.— Carpenter 
P7'mc. Comp. Phys. ed. iv. pp. 50 — 58. 

PoLYZOA, J. V. TJiompson. Zool. Res. Mem. v. 92.— J. E. Gray 
in Si/n. B. M. 133.— Johnstons Br. Zooph., i. p. 253, ed. 2 : 
V. note. p. 25-1.— Busk in Ann. Nat. Hist. 2nd Ser. vol. 10. 
p. 362. 

MoLLUscAN Zoophytes s. Zoophyta Ascidioida, Johnst. in 
Mag. Zool. 8f Bot. i. 448. 

CiLiOBEACHiATA, Farre in Phil. Trans. 1837. 

Polypes tuniciens, M. Edio. Mem. 16. 

Order I. BRYOZOA INFUNDIBULATA. 

P. Gervais in Ann. dcs Sc. Nat. vii. 79. — Johnst. Br. Zooph. i. 
255. 

Suborder I. CHEILOSTOMATA. 

Family MEMBEANIPOKIDiE. 
Membraniporidse, Busk, B. M. Cat. p. 55. 

Genus MEMBKANIPOEA, Blainv. 
Menbranipora, Bitsk, B. M. Cat. p. 56. 

1. Membranipoka denticulata, Busk, (n. s.) 
Areis cellularum rhomboideis ; aperturd interiori inargine 
denticulato. 

Tlie outline of the cells is usually distinctly defined by a 
narrow brown line. One or two rounded or triangular eminences 
(probably ovicells,) arc visible on many of the cells in front 

July. 1855. 6 



i MAZATLAN BBYOZOA 

and below. This form beai's considerable resemblance to Mem- 
branipora Savartii {Scmgny, Egypt, pi. 10; M. Lacroixii B. M. 
Cat. p. 60, pi. 104, fig. 1.) : but diiiers from it in several impor- 
tant respects ; among wbicli may be noticed tbe narrow brown 
line surrounding tbe cells and clearly defining one from tlie 
other ; and the irregidarly shaped branching denticles with 
which the margin of the interior calcareous aperture is fur- 
nished. 

Hah. — Mazatlan ; on the shells of Imperator olivaceus, Imp, 
imguis and Anomia ; Liverpool Collection. 
Tablet 1 contains a group on Imperator. 

2. Membeanipoea gothica, Rylands, ms. (n. s.J 

Arei.9 cellularum eloiigatis, ovalibus ; margine glabro. tenui ; 
ore elevato, suborhiciclan, ivferne late sinuato ; cellularum 
superjicie anteriori calcarea depressd, jiunctata, orificio magna 
utrinque perforata ; aviciilariis magnis, immersis, irregulariter 
per 2}olyzoanum sparsis. 

There is occasionally a short blunt spine or process on each 
side of the mouth, a character which also exists in M. Eozieri, 
Savigny, (B. M. Cat. p. 59, pi. 65, fig. 6.) a species to which the 
present exhibits in other respects considerable resemblance, 
and especially in the existence of the large opening on each side 
of the front of the cell immediately below the mouth. The 
clifFerences between the two, however, are sufficiently sti'iking. 
In M.. Eozieri the ovicell is large, superior, rounded, and carinate 
in front ; whilst in M. gothica, as in M. calpensis. Bask, &c., 
this organ appears to be represented by one or two rounded 
eminences at the bottom of the ceU in front. The large scat- 
tered avicidaria also, are characteristic of the present form, as 
well as its much larger size. 

The same species occurs on a pearl-oyster shell, for which 
I am indebted to Dr. J. E. Gray ; the habitat assigned to which 
is doubtfidly given as the Persian Gidf. In SI. ^M. Edwards' 
Memoii' Sxr Ics Escharcs, p. 17, pi. 12, fig. 13, a miocene fossd is 
described and figured, which bears considerable resemblance to 
the present ; it difiers principaUy, so far as can be determined 
from the figure alone, in the thickened and gran\ilated margin 
of the area. 

Kah. — JMazatlan : on Imperator olivaceus and xinguis ; L'pool 
Col. 

Tablet 2 contains a group on Imperator. — 3, a group detached. 



MAZATLAN BEYOZOA 6 

Genus LEPEALTA, Johnston. 
Lepralia, B. M. Cat. p. 63. 

3. Lepkalia ATEOFtrscA, Rylands, ms. (n. s.) 

Cellulis elongatis, ovatis seu rhomboideis, lined tenui elevatd 
cinctis, supei'fieie punctato ; ore suhorhicidari, inferne sinuato, 
utrinque denticulato. 

General liue, blackisli ; aud even when tlie cells are more 
calcareous and on that aceoimt whiter, the dai'k interstitial 
line remains very evident. It is quite distinct from L. cncullata. 
{B. 31. Cat. p. 81, pi. 96, fig. 4, 5,) also of a black colour, and 
which occurs in the Mediterranean. 
Sab. — Mazatlan ; on Imperator oUvaceus and unguis, and on 

Anomia; L'pool Col. 

Tablet 4 contains 2 groups detached. 

4. Lepealia teispinosa, Jolinst. 

B. M. Cat p. 70, pi. 85 ; fig. 1, 2 ; pi. 98 ; pi. 102. fig. 2.— 

Johns. Br. Zooph. i. 324, ed. 2 ; pi. 57, f. 1 .—Couch Corn. 

Faun. iii. 118. — J. Macgillivray in Ann. Sf Mag. N. Hist. is. 

467. 
Discopora trispmosa, Johns, in Ed. Phil. Journ. xiii. 822. 
Berenicea trispinosa, Johns, in Trans. Newc. Soc. ii. 268. 

A single minute specimen only has occurred to my notice, 
but this is quite indistinguishable from the British form. 
JIab. — On shells from deep water, rare, Berwick Bay. Johnston. 

Coast of Cornwall, Peach. — On root of Laminaria digitata, 

near Aberdeen, 3Iacgillivray . — Mazatlan ; on Imperator ; 

L'pool Col. 

Tablet 5 contains the group. 

5. Lepealia Mazatlanica, Busk. (n. s.) 

Cellulis immersis, depressis, sen, ventricoso-globosis ; superficie 
punctato; ore suhorbiculariinfeme late sinuato ; margine incras- 
sato, elevato ; aviculario unico fvel rare, duobus) lateraliprope os. 

This form might easily be confoimded with some varieties of 
L. vmicornis, or L. BaUii. It is distLngiiished, however, by its 
reddish colour, and the elevation of the mouth together with 
its thickened margin. ' The single or sometmies double avicu- 
larium points outwards and upwards, and the mandible is pro- 
longed and acute. It is sometimes, but not frequently absent. 
Uab. — Mazatlan ; on Imp. olivaceus and unguis ; Upool Col. 

Tablet 6 contains a gi-oup on Imperator. — 7, one detached. 



4 MAZATIAN BRYOZOA 

6. Lepbalia eostrata, Busk, (n. s.J 

Cellulis immersis, sitperjicie tuherciilatd sen granulatd ; ore 
immersG, maryine siiperiorl incoiispicuo ; margine ivferiori pro- 
fimde siilcato ; aviculario magno, sessili, armato. 

The lower or interior margin of the month in the fully formed 
cells, is deeply grooved in the middle ; and on one side of the 
sulcus is a strong, short, blimt, spinous process ; on the other 
a comparatively large raised avicularium, which faces towards 
the sidcus, and whose mandible is acute and points upwards 
aud outwards. The surface of the cell is often beset with short 
raised spines or processes ; and these, projecting over the mouth 
of the cell below, give it the appearance of being furnished with 
several oral spines. 

Hah. — Mazatlan ; on Imperator unguis ; L'pool Col. 
Tablet 8 contains a gi'oup on Imperator. — 9, one on base of do. 

7. Lepealia maeginipoba, Heiiss. 

Fo.isil Tolyp. d. Wiener Tertiar. BecTc. p. 88, pi. 10, fig. 23. 

Cellulis ovatis, convexis sen. suidepressis, immersis, aspenilis, 
margine pnnctatis : ore rotundo sen subelliptieo ; margine suh- 
incrassato, singulo latere avicnlarinm gerente. 

As the form appears precisely to resemble the tertiary species 
described and figured by Eeuss, I have aiiplied his name, and 
in great i^art emi^loycd his character. 
Hub. — Mazatlan ; on Imperator unguis ; JJpool Col. — Fossil, 

Vienna. 

Tablet 10 contains a group on Imperator. 

8. Lepbalia hippocbepis, Bn,'ik, (n. s.J 

Cellulis immersis, snperjicie punrtatis ; ore snborbiculari seu 
elVq^tico ; margine snperiori cellularmn natu niajorum, inco7ispi- 
cuo, ivferiori et laferali incrassato utrinque avicularium gerente. 

The peculiarly horse-shoe shaped mouth of the older cells, 
.s\xfficiently distinguishes the present from the preceding species, 
to which, in tlie mouth alone of the yoimger cells, it bears some 
resemblance. 

Sab. — Mazatlan; on Imperator olivaceus ; L'pool Col. 
Tablet 11 contains a gi'oup on Impetator. 



MAZATLAN BEYOZOA O 

9. Lepbalia humilis, Busk, {n. s.J 

Cellulis immersis, depressis sen comjdanatis, superjicie obscure 
punctatis ; ore parvo rotundato, inferne suhsinuafo ; margine 
simplici, tenui. 
Hab. — Mazatlan ; on Imperator unguis ; L'pool Col. 

Tablet 12 contains a gi'oup on Imiierator. 

10. Lepealia adpeessa, Busk. 
Bush mB M. Cat. p. 82. 

Tlie Mazatlan form differs from that from CMoe in the 
absence or indistinctness of the radiating grooves. The moiith 
and shape of the cell agree perfectly. 
Hab.—ChSloe, 96 fm. on shell, Dancin. — Mazatlan ; on Cokmi- 

bella major, C. fuscata, and Pisania genimata, not imconmion ; 

Upool Col. 

Tablet 13 contains a group on Columbella. 

Family H. CELLEPOEID^. 
Busk, B. M. Cat. p. 85. 

Genus CELLEPOEA, 0. Fabr. 
Busk, B. M. Cat. p. 85. 

11. CeLLEPORA PAPILL^FOSMIS, Busk, (n. S.) 

Cellulis suh-hexagonis. elevatis, siiperjicie punctata ; ore sub- 
rotundato utrinque denticulato ; margine simplici, tenui, avicu- 
lariis sparsis, mandibulo triangulari. 

A weU marked and distinct form, belonging to that subdivision 
of CeUepora in which the mouth is not armed with a projecting 
avicularium. The top of each cell projects in the form of a 
roimded mamillary eminence from a hexagonal area which 
defines the border of the cell. The cells are of very unequal 
sizes, and very iiTegularly disposed. It is of a brownish colour. 
Sab. — Mazatlan ; on Imperator olivaccus ; L'pool Col. 

Tablet 11 contains a group on Imjierator. 

12. Cellepoea cyclostoma, Busk. (n. s.J 

Cellulis subereciis, seu decumbentibus, discretis, supeo'Jicie 
punctaio ; ore magno superne rotundato, inferne late sinuato ; 
cellularum natu majorum margine valde elevato, incrassato, sub- 
inde dilatato, infuiulibuUformi, utrinque avicularium parvwm 
gerente. 



G MAZATLAN BETOZOA 

The wide, rounded or elliptical raised margiu of the mouths 
of the distant cells gives the polyzoarium of the present species 
a very pecidiar and well marked aspect. It is of a brownish 
hue, or white. 

Hah. — Mazatlan ; on Imperator unguis ; L'joool Col. 

Tablet 15 contains a group on Imperator. — 16, a gro\ip de- 
tached. 



SuBORnER II. CYCLOSTOMATA. 
FAMILY DISCOPOEAD^. Busk, (ms.) 
Genus DEFEANCIA, Brmm. 

13. Defeancia inteicata, Busk, (n. s.) 

Disco valde irregulari ; irrer/ulariter radiatim costulato ; ori- 
firiis tuhulorum, porisciue interstitialibus cequalihus magnitudine. 

The small in-egular patches appear to be constituted by the 
confluence of several sets of costal with their corresponding 
interstices, each set radiating from a depressed central point. 
It differs from D. deforrais Reuss, (L. c. p. 36, pi. 5, f. 2-4) in 
the uniform size of the openings of the tubes in the costse and 
of the pores in the insterstices. 

Hah. — Mazatlan ; on Imperator unguis ; L'pool Col. 
Tablet 17 contains a group on Imperator. 



Besides the above, there occur on some of the shells, indica- 
tions of other species, but in too imperfect a condition to allow 
of their determination. Among these perhaps the best marked 
is a species strongly resembling Cellepora pumicosa, Li»., a 
species of Lepralia, and of Tubulipora. 



CLASS TUNICATA. 

Omnia adhuc ignota. 



MAZATLAN BIVALVES 7 

CLASS PALLIOBRANCHIATA, Blainv. 

Bracliiopoda, Cm. Bracliiopoda and Rudista (pars) Lam. 
Palliobrancliiata, Blainv. 

Family DISCIISTD^. 
Gexus DISCINA, Lam. 
Discina, Lam. 
Orbicula, Soio. not Cuv. or Lam. 

14. Discina Cumingii, Brad. 
Orbicula Cixmingii, Brocl. in Proc. Zool. Soc. 1833, p. 125. — 
Brod. in Trans. Zool. Soc. i. 143, pi. 23. f. l.—Milll. St/n. Test. 
Vlv. p. 175. — Layn. An. sans Vert. Desk. ed. tert. iii. pt. i. p. 
118. no. 3.— Sow. T/ies. Conch, p. 366. no. 4. pi. 73. f. 6.— 
D'Orh. Voy. Amer. Merid. Moll. p. &J1.—B. M. Cat. of 
D'Orh. Shells, no. 786, p. 89. 
Discina Cumingii, Davidsons Class, of Brach. in Brit. Fos. 
Brack, vol. i. p. 129. 

This shell is tbe Pacific analogue of D. striata, wbicli pro- 
bably belongs to tbe Atlantic. Some specimens of each species 
are liard to distinguish from the other. D. Cumingii varies 
greatly in form, according to the place of its attachment, and is 
often extremely thin, and scarcely shelly. This is always the 
case Tvith the lower valve, which has its disk of attachment 
subtorminal, covered Avith a thin skin except at a very small 
chink. The upper valve is generally smooth near the apex, 
which is occasionally subcentral, afterwards closelj' set with 
radiating strise, more or less developed, and generally (not 
always) decussated by slightly raised lines of growth. Some- 
times nearly the whole of the upper valve is smooth and thru, 
as in Iffivis. The lower valve generally displays only the con- 
centric lines of growth, but is occasionally decussated near the 
edge. It is sometimes so convex as to allow scarcely any space 
for the animal. Muscular impressions not so strongly marked 
as in D. striata. The young shells are often fringed round the 
edge, (with the remains of the cilia, Brod.) Colour, brownish 
yellow. The largest valve measures, Zow^. "47, ff?^. 'OS in. 
Sab. — Paj^ta (Peru), St. Elena, Panama, attached to lo-ner sides 
of stones in sandy mud at low water — G fm. : Cuming. — Payta, 
Ecuador, St. Elena, D'Orhigny. — Seas of C]iili[P] and Peru, 
Deshayes. — Panama, common, under stones at low water, 
C. B. Adams. Mazatlan ; on Ostrea iridescens and Virginica, 
Chama^, Pinna", Spondylus Lamarckii, Strombus galea, in um- 
bilical chink of Vitiilaria salebrosa ; rare, L'pool Sf Havre Coll. 



Q 

° MAZATLAN BIVALVES 

Tablet 18 contains 8 rakes, very young, iu test tube.-Tablet 
W contams 4 adult valves.-Tablet 20 contains Ostrea Vii-ginica. 
witli Cliama Pspmosa attaclied, and 3 fine specimens of D 
Cummgu in situ. One is removed from its nestling place be' 
tween the Cliama and Oyster, and laid open to shew the iBside. 

CLASS . LAi\IELLIBEANCHIATA, Blainv: 
Conchifera: Lam. FMl. Zool.Ym ; An s. Vert.x.m, ed 2 

rsi;^ 183^' ^''- ^- ^- ^^' ^*^' P- ^2 ' ^'''- ^''^- ^<^^- 
Acephak Lamellibranchiata: Hang, Man. Moll. 2l2.-Forbes 

and SanL Br. Mol. i. bo.-Clarl; Moll. Test. Mar. Br. 23. 

Family PHOLADID^. 
Pholadidae, Gray, P. Z. S. 

GexXtjs PHOLADIDEA, Titrt. 

Pholas, Lin. Lam. 

15. Pholadidea melantjea, Sow. 
Pholas melanura, Proc. Zool. Soc. 1834, p. 70.-Sow Thes 
Conch. 1849, p. 409.-5. 3L Cat. D-Qrh. Shells, no.m, p S 
This belongs to the same group of species as tridens, quadra 
sparhatula, and concamerata, which last represents it on the 
OabJorman coast. In its posterior cup-like appendages, it re- 
sembles Talona clausa from the Gambia. The sheU is extremely 
thin, shewing inside a row of oblong tubercles impressed from 
without on the Ime separating the anterior and posterior por- 
tions, as weU as the anterior ridges. These are closely set 
strong, and waving ; and passhig over the medial depression 
at an angle slightly ^videniug as the sheU becomes adidt are 
contmued, ccrucentric and straight, graduallv fading as 'they 
approach the posterior extremity. This is covered with a thick 
epidermis, endmg m a short double cup, which is bi-lobed 
outside and simple within. The adiUt closing of the valves is 
carried m a flat expansion round to the umbos. The lar<rest 
specunen measures, with the cup, long. "9, lat. I'So, alt. S'l 
Sah.—lxi hard clay and loose stones at low water, Monte Christi 

(Cxuayaqiul), Cuming. ~Ecvl&6lot, Monte Christi, D'Orbignt/. 
Mazatlan ; in company with P. acuminata, extremelv 

rare ; L'pool Col. 

Tablet 21 contains the most characteristic (though a some- 
what imperfect) specimen. 



MAZATLAN BIVALVES 



16, Pholadidea Pctteta, Sow. 



Pholas curta, Proc. Zool. Soc. 1834, p. 71— -B. M. Cat. UOrb. 
Shells, no. 482, p. 56. 

The only two specimens fotuid are too imperfect to identify 
witli accuracy. Tliougli very small, they are both, adult, and 
are known at once from the young of melanura by the extreme 
fineness of the anterior waved striae, the posterior part scarcely 
shewing more than Hues of growth. Dorsal plate shield-shaped, 
in two layers, hollow within, rather lai'ge and regidar. Long. '28, 
laf. -34 ; shield '17 by 'lo. 

Hah. — Isle of Lions, Veragua, in soft stone at low water, Cum- 
ing. — Ecuador : Isle cle los Leones, [?]D'OrbignT/. — Mazatlan, 
in Strombus galea, Savre Col. 

Tablet 22 contains 1 valve (the other being broken in extrac- 
tion) with its plate. 

Genus PAEAPHOLAS, Conr. 
Parapholas, Conrad, sp. 

This genus, including Californica, Incii (Torres Str.), branchi- 
ata, calva, (acuminata,) and bisulcata (Woodw.) differs from 
Martesia (Leach) in having its cup laminae persistent and imder- 
lapping one another. It further differs from Pholadidea in 
the large size of the umbonal plate, and the gaping in the ven- 
tral and dorsal margins, closed by plates in the adult shell. All 
3'et known are from the Pacific. The Californian species is of 
large size, and makes a sheUy tube for its siphons. 

17. Paeapholas calva, Gray, ins. 
Pholas calva Sow. in Froc. Zool. Soc. 1834, p. 69. — TJies. Conch. 

1849, p. 493. 

Animal excavating a pear-shaped burrow in shell (or stone) 
which is perfectly smooth and circular transversely, so that the 
shell |(till it becomes adult) can move freely round in it. The 
orifice is subcircular, and rather large. As the annual continues 
its boring deeper, the swoUen anterior portion becoming now 
posterior and therefore too large for the animal, which loves to 
have just room enough and no more, the vacant space is filled 
up with a lining (more or less thick according to the depth of 
the buiTow) which is not an organic growth from the mantle, 
but appears to be nothing more than a sedimentary deposit 
in layers. Whether the burrow is in the pui^ple or white 
portion of the Spondylus, the deposit is always dai'k grey. 
It may be detached as a tube from the cavity, and is often per- 



10 MAZATLAN BIVALVES 

forated by otker borers. The deposit is rarely seeu in young 
shells, but is common in adolescent and ? universal in old speci- 
mens. At the bottom of the burrow is generally seen an irregu- 
lar mark projecting beyond the smooth surface of the hole, 
formed by the Pfoot of the animal. Sometimes this is onl.y a 
"scar, strongly resembling an irregular oval muscular impres- 
sion with an elevated marginal ridge from which it smks back 
to a deep central linear depression, the vrhole strongly marked 
with concentric and radiating furi'ows." (Darhishire) . More 
often there is a sort of side chamber, or shoe, irregidarly exca- 
vated in the shelly matrix, and not always in the same relative 
position, the siu-face of which is warty and very irregidarly 
corrugated. This is generally filled with a black horny sub- 
stance, giving an animal smell when burnt, but not displaying 
any silicious particles. Li very old specimens this excavation 
is often enormously developed, occasionally reaching up be- 
tween the grey deposit and the shelly matrix. Even -in rather 
young shells this foot-chink is sometimes seen ; and whenever 
"the burrow reaches the inside of the Spondylus, the black 
substance is always first apparent. ? Does the foot make this 
lodgment as a fidcrmu, while the valves spin round and form 
the burrow : and after the adidt valves can no longer move, 
Pdocs the foot amuse itself with forming these superfluous 
excavations. 

Shell, when extremely young, of xylophagoid shape, -with the 
ventral portion imdeveloped and the cup-lamina3 only existing 
as slight folds of the epidermis. Soon however two radiating 
lines become developed, and the ventral part rapidly increases. 
Throughout the younger portion of its life there is a very large 
dorsal as weU as ventral gape. The anterior edge is marvelously 
thickened, ending in a stout knob, quite capable of aiding in bor- 
ing execution. In the single specimen found in a ti-ansition state, 
this knob is no longer prominent, and the anterior gape is par- 
tially filled witii shell, not smooth as in the advdt, but gradually 
carrying off the ribs of the thicker portion. 

Adult shell squarish or rounded anteriorly, short or length- 
ened, presenting all the intermediate forms between calva and 
acimiinata of Sow. ; fitting so tightly into its biUTOw that when 
dried it is often impossible to remove it without fractiu-e, the 
umbonal plate being finnly adherent to the matrix. The epider- 
mis is thin on the anterior part ; over the ventral part, folded 
in thick concentric layers, every 4 or 5 of which (varying in 
number) are as it were joined together along the posterior line 
into a series of tiles ; and thence continued in a series of over- 



MAZATLAN BIVALVES 11 

lapping homy lamiuse over the posterior portion. The snout 
is nearly round outside, displaying the gaping ends of the valves 
within, and a bi-partite lamina, rather rugose, between the two. 
The margin is entii'ely closed (except at the anterior part) with 
thick' horny epidermis, strengthened ventrally by a long narrow 
plate, not only fiUing up the gape of the young shell but 
projecting beyond the knob (now absorbed) into the anterior 
portion ; smooth, with a faint line in the middle : and dorsally 
by a thicker plate, with rather rounded lorojecting edges more 
or less swollen towards the umbos. These, with about a third 
of the surface of the valves, are covered with an irregularly 
shaped shield, smooth externally, encircling part of the dorsal 
plate, and with an internal, bi-partite, anterior lamina, fitting 
the valves. Between this shield and the hinge there is vacant 
room, but there appears no place of exit for the foot except 
at a veiy slight anterior chink, which seem to be aU that the 
stretching power of the integuments can allow. The markings 
within vary considerably, the thick anterior ridge being often 
quite absorbed, and the hinge apophj'ses in'egular. 

See a very full account of the animals of British Pholadidse, 
and the relations between iamellata and papyracea of Turton, 
in Clarh's Moll. Test. Mar. Brit. p. 169—212. 

The following are measures of different specimens : — * 
Largest (Acuminate) Long. "99 Lat. 1'93 AU. .98 

Shorter fonn '81 1"45 "78 

Smallest adult 'So '67 '34 

Smallest jun. 'Oi -06 p-04, 

Hah.—K^^At in Spondyli, 12 fm.. Isle of Perico in Panama 
Bay ; jun. in hard stones at low water, id. ;\ Cuming. — Mazat- 
lan : abundant in Spondylus Lamarckii : also in ? primitive 
(not limestone) rock to which the Spondyli are attached ; 
2 yoimg specimens m Cham», and 1 in Strombus galea : 
Upool Sf Savre Coll. 

Tablet 23 contains 8 valves very young.— 24, 9 young speci- 
mens varying in size and acumination. — 25, a young specimen 
with a part of its o^vn bun-ow, in the tooth of a Spondylus, 

* In this family, and in Gastrochaenidfp, the length was measured straight 
across, not to the middle of the ventral margin. 

t This is the accurate statement in the Proc. Z. S. : in the Thes. Conch, it is 
given as "collpcted by Mr. Cuming in very hard stone at low water in Panama 
Bay;" making it appear that all the specimens were thus (;olleeted, whereas the 
adidts were found in Spondyli, 12 fm. deep. Similarly careless transcripts are not 
uncommon in the Monographs, 



12 MAZATLAN BIVALVES 

shewing the grey lining and part of the pedal chink.— 26, the 
adolescent specimen— 27. 6 adult specimens shewmg various 
peculiarities of groTvth.— 28, a small adiilt specmien in situ, 
with a thick iiTegular liaing : another specimen remams en- 
tombed— 29, an adult with part of its biu-row, shewing the 
sti-atified nature of the lining : the anterior portion of the shield 
curiously deformed— 30, a piece of Spondylus, with 3 young 
specimens in situ, and several bun-ows, shewmg the stratihed 
lining, and the pedal excavations reaching the mside of the shell, 
to the evident annoyance of the Spondylus, which has protected 
itself ao-amst one of its enemies by a protuberance 7 across, 
and -23 high.— 31, a large piece of Spondylus with various 
buiTOws : a" large one of calva, with enormous foot chmk : a 
smaller one in the hmse tooth ; two others with small foot 
marks • a burrow of PLithodomus encased from an old hole 
into which it had penetrated : a singidarly t^visted burrow of 
Gastrochfena, bent nearly double, &C.-32, fragnients ot the 
hornv Pfoot.— 33, frascments of the grey deposit.— 34, fragments 
shewincr binge structure.— 35, fragnients illustratmg the ciip- 
laminfs.- 36, portions of the umbonal plate.— 37, portions of the 
dorsal and ventral plates. 

18. Pakaphoxas acuminata, Sow. 
Pholas acuminata, Proc. Zool. Soc. 1834, p. 70.^Sow. Thes. 

Conch. 1849, p. 492. 

The author of this species distinguishes it from calva by the 
shape of the lamina^ and posterior portion, which are variable 
in both forms ; and by the character of the umbonal shield 
This last is the only constant character of diflerence. it is not 
only smaller, not projecting beyond the dorsal plate ; (which is 
not the residt of age. behig found in aU the specimens ;) but, m 
all the specmiens allowing of observation, it is tnrned-m aU 
round, instead of at the anterior portion only as m calva. ilie 
external surface also is generally rougher, and the posterior 
<rape smaller, not displapng the bipartite lamma so clearly. 
Still as the shells exactly agree in aU other respects, it is pro- 
bable that these differences only residt from changes m situation. 
All the calva. were taken out of Spondylus: aU the acumi- 
nata, were sent loose ; and from their extremely P;rfect^con 
dition were probably extracted from clay or wood. If the latter, 
the irregularities of the decaymg timber might cause the 
ron-hening of the plate-surface. Tlie origmal specimens of 
IJuminata however were taken out of argdlaeeous limestone. 
The largest specimen measures long. "8, lat. 1 D4, alt. u. 



MAZATLAN BIVALVES • 13 

Rah. — Panama, in limestone rocks at low water. Caining. — 
Mazatlan ; not uncommon ; L'pool Col. 

Tablet 38 contains 3 normal specimens. — 39, 3 do. distoi'ted. — 
U), 2 do. shewing iaside, and plates. 

Gexus MAETESIA, Lmcli. 

Difiering from Pholadidea in the large development of the 
accessorj' plates ; from Parapholas in the cups not being per- 
sistent. 

19. Maetesia intekcalata, n. s. 

M. t. parvd, subglobos a, in cluas partes divisd ; parte 
anteriore tenuissime concentnce striata, radiis longitudinalihus 
suhohsoleti^ tux undatd ; in Juniore maxime Idante, margine 
soUdo ; in adiiltd secretiotie semi-corned clausd : parte posticd 
sublcEvi, epidermide copiose indutd, margine rotundato ; um- 
honihus testd r^exd adhferente ccelatis ; clypeo pyriforme, parvo, 
solido, inter sec r etiones valv a r u m i n tervala nte ; 
partibus ventrali et dorsali laminis semi-corneis, brevibu-s, a 
ralyce repulsis ; calyce piano, brevi, simplici, extante. 

The species is named from the remarkable way in which the 
imibonal shield i)ushes itself in anteriorly between the project- 
ing portions of the closed valves ; and in wlxich the ciip, Avhich 
pouts out from the otherwise rounded extremity, inishes itself 
in between the anterior and posterior plates, cleaving them and 
thrusting them back. Mr. Hanley was fortimate enough to 
find two specimens burrowing in Spondylus, of which the larger 
has not yet closed the anterior portion, but the smaller is adult. 
The shield does not fold roimd the dorsal plate. The whole 
dorsal and posterior part has a thickened raised margin, \no- 
bably epidermal. The largest (adolescent) specimen measures 
long. '34, lat. "35, alt. "33. The cup in the smaller specimen 
measures '06. 

Hab. — Mazatlan ; in Spondylus Lamarckii, extremely rare ; 
Havre Col. 

Tablet 41 contains various magnified sketches of the two 
specimens in Mr. Hanley's collection. 

20. . 



A curious little fragment, unfortunately too imperfect for 
identification, which may belong to a Pholad, but is certainly 
distinct from any of the foregoing. Shell with a strong, irrc- 
Aiig. 1855. c 



14 MAZATLAN BIVALVES 

"•ularly curved tootli, deeply channeled on the convex side, 
appressed to the umbo and projecting considerably above the 
margin of the valve. No process on the hinge as m Pholas. 
and apparently T^-ith groove for external ligament. Outside 
oval, smooth near imibo, afterwards mth slight concentric 
rounded ribs and very slight radiating furrows. 

Tablet 42 contains the fragment, and a magnified sketch. 

Family GASTEOCH^NID^. 
Genus GASTEOCH.^NA, Spengler. 

21. Gasteochjjna teuncata, Soiv. 

Pruc. Zool. Soc. 1834, p. 21. 

Animal excavating a smooth oval chamber at the end of a 
llattened narrow gaUery, occasionaUy five times as long as 
the chamber itself.* The gaUery is straight, variously bent, 
or even suddenly recurved at a considerable angle, according 
to circumstances. It is always lined with a sheUy coat, not 
evidently difi'erent from the shelly matrix, but separable 
from it. The interior of the siphon gaUery is more or less 
rugose, and towards the extremity is nearly bipartite Ihe 
Di-esence of these creatures may always be detected by the 
S-shaped holes they make ; but there is no clue by which the 
probable place of their abode fcau be ascertamed. ^ hen they 
make a sudden turn, in consequence of some knowledge of an 
approaching stranger even at a distance, they fiU their discarded 
burrow with sheUy lining. The English species has no objec- 
tbn to burrowing through the graves of departed brethren 
carrying its tube across them: tliis was no noticed m anj 
Mazatlan specimen. A ? foot mark is often observed opposite 
Jhranerior gape, but never so large as m Parapholas : occa- 
sionX m the adolescent shell, a chink is seen in a do^vnward 
direction, fiUed with the black horny substance 

The valves have free room to open widely m the cavity. lUe 
form varies, even in the young shell, and often, both in outlme 
and markbgs, approaches ovata. It may be known at once 
howe^r by the great pecidiarity of the hinge; m which the 
"ma 1 spathulatt lamina" which Forhes .f IM- l-'^ve record- 
ed in the r generic character, though scarcely observable m G 
, od dina, assumes dimensions whicli abnost entitle it and 
Sar species to subgeneric rank. Umbos very near anterior 
g^^ anmdistinct diagonal line beyond which the concenti-ic 
• Mr. DarbisWre found one which measured 4- 5 in. exclusive of the ceU. 



MAZATLAN BIVALVES 15 

striae are coarser and more irregular. This (posterior) portion 
of the shell is covered with very copious ei)idermis, in wrinkled 
folds, as ia Saxicava rugosa. Ligament long. The yoimg shell 
has projecting umbos, and often serrated edges to the anterior 
gape. The largest specimen measures long. '57, lat. 1"17, alt. 57. 
The smallest valve, long. "02, lat. "05. 
Hob. — In Spondyli, Isle of Perico, Panama, Cuming. — Mazat- 

lan ; not imcommon ia Spondylus Lamarckii, very rare ia 

Chamse, Patella Mexicana, and in Imperator olivaceus and 

unguis ; L'pool Sf Havre Coll.* 

Tablet 43 contains 6 valves very young, and .3 pairs adolescent. 
41, Yoimg specimen, piercing the apes of Imperator unguis. 
45, do. Imi). olivaceus, with Bryozoa, &c. attached. — 46. Young 
specimen in situ in Imp. olivaceus, T^ith another yoimger, coter- 
minal. — 47. Young specimen in Imp. oHvaceus, with tube some- 
what projecting, whicli is unusual at Mazatlan. — 48. 1. oHvaceus 
broken across, and shewing 5 specimens of G. truncata, and 
one Lithodomus caudigerus, invading the Imperator's liver 
chamber. — 49. Adolescent specunen in situ in fragment of 
Spondylus, -R-ith the tube laid bare, and the pedal chink and 
deposit. Also portions of several other tubes of Gastroch^na, 
Lithodomus and Petricola.— 50, 3 adult specimens varying in 
outline, of which one displays a pearl formed near the hinge, 
another a lamina cutting off a large part of the anterior end, as 
often happens in large aged fossil Sasicavse.— 51. Fragment 
of Spondylus, displaying hole of G. truncata, which, having 
approached a Lithodomus too closely, has turned round, filling 
the vacant space with shelly matter.— 52. Siphon pipe laid bare, 
by the decay of the worm-eaten Spondylus around : also bur- 
rows of Lithodomus plumida and Parapholas calva.— 53, Pipes 
and thick lining of 3 Gastrochsena; in Patella Mexicana : the 
two siphons in one are ail-but separated at the extremity.— 
54, 2 pipe-ends from Spondylus.— 55, Fragments of sheUy lining. 

22. Gastroch^ina ovata, Sow. 
Proc. Zool. Soc. 1834, p. 21. 

Burrow not differing perceptibly from that of G. truncata. 
Shell, when fresh, of a delicate lUac tinge, with sharp elegantly 
bent concentric ridges foUo^-ing the inargin, closer at the an- 

*In the Bristol Institution is ,a Tablet marked G. cuneiformis, from the West 
Indies, 3Ir. Friske, containing 2 specimens ; of which one I was unable to separ- 
ate from G. ovata, the other (in its burrow) from G. truncata. Mr. Hanley 
states, from the examination of a collection made by M. Bean in Guadaloupe 
and sent to him by M. Petit, that several species of borers are common to the 
iTvo oceans. 



1*> ' ifAZATLAX BIVALVES 

terior part. Epidennis not conspicuous. Lunular iiortion deeph^ 
impressed : umbos distant from margin. Hinge without spatli- 
ulate lamina : mantle marks rugose. More or less elongated, 
approaching sometmies the more ovate forms of truncata, especi- 
ally in the yoimg shells, but distinguished at once by the hinge. 
The anterior margin in the yoimg shells is generallj- serrated, 
like Pholas. more strongly than in truncata. Anterior por- 
tion either more or less than one-fifth of the entire length. 
The largest specimen measures long. '76, led. I'l, alt. 6 "2. 
Smallest, long. -04-, led. "08. 

Sah. — Isle of Perico (Bay of Panama) and Isle of Plata, Cum- 
ing. — Mazatlan ; in Spondylus Lamarekii, very rare ; Upool 
S^' Havre Coll. 

Tablet 56, 1 valve and 2 pairs verj- young. — 57, young speci- 
men m situ. — 58, 2 adult specimens : one lUac, fresh ; the other 
white, large, dead. — 59, fragments of shelly lining. 

Family SAXICAYID^. 
Genus SAXICAVA, Bellevue. 

23. Saxicava akctica, Lin. 

(For the synonyms, both as to genus and species, of this 
Protean shell, see B. M. Cat. Brit. An. Part A'll. pp. 86—89.) 

? = Saxicava solida. Sow. Pvoc. Zool. Soc. 1834, p. 88: D'Orh. 
Voij. V. 521. 

y = Saxicava Cordieri, Gould, ms. — Mazatlan, Lieut. G-reen. 

This shell is named on the authority of E. M'Audrew, Esq. 
whose practical acquaintance with the foi-ms it assimies both in 
Arctic and subtropical regions renders his opinion of weight. 
According to Ilanley, Menke and Gould, it is a distinct species. 
I cannot separate some forms of it from solida. The creature 
seems to take delight in distorting itself, not thinking it neces- 
sary to lodge in an uneven cavity for that piirpose. It seldom 
(if ever) bores, being foiuid in cavities of Lithodomus <tc. The 
young shells are just as variable as the old ones, sometimes 
assuming the characters of S. rugosa or the form of Spha>nia 
Binghami, but generally displaying the narrow, anteriorly trun- 
cate, bi-tuberculate cliaracter of S. arctica. It rarely takes the 
genuine Hiatella form. Ligament of variable length, generall.\- 
rather short. A'alves capable of opening widely, though rarely 



MAZATLAN BIVALVES 17 

in a position to do so. Hinge teeth, 1 in eacli valve, rarely 
seen in adult. 

Largest specimen measures long. '63, lat. 1'17, alt. '4,7, 

A broad flat sp. „ . „ '4, „ -68, „ '24, 

A long narrow one ,, ,, '3, „ '66, „ '2, 

SmaUest „ „ '02, „ -04, „ 'OlS. 

Hab. — According to Forbes, Atlantic Ocean, Boreal Seas, 
Africa, Ckina, Australia. — Canaries, JFebb (Sf Bertlielot, B. M. 
Cat. Can. Moll. p. 22, no. 195. — jSTew Zealand, Cajj^. Stohes, 
B. M.— *S. solida -. Clefts of rocks, 18 fm. St. Elena, Cuming : 
Pei-u, Lima, CaUao, D' Ot-higni/, B. M. Cat. p. 58, no. 510.— 
S. distoHa, Say, Rbode Is. Jay.— 8. Pholadis, Sea of Okotsk, 
Jf «Me?wZo?/.— Mazatlan ; in Spondylus Lamarckii, nestling in 
crevices and burrows, also in Cbamas and. Patella Mexicana, 
very rare advdt, not common jim. ; Upool Sf Havre Coll. 
FossU, Crag, &c. ; very large in the pleistocene beds at Ud- 
devalla, Sweden, B. B. B. 

Tablet 60, 6 young valves.— 61, 1 valve and 6 pairs various 
ages and shapes. — 62, 1 specimen bored into, and the A^alves 
cemented open by tube of borer : also 2 fragments to shew 
ligament. — 63, A young specimen in hole of Lithodomus cau- 
digerus in Imperator unguis. — 64, A specimen in situ in a Ver- 
metus, oiFback of Spondjdus. 

Family PETEICOLID^. 

Genus PETEICOLA, Lam. 

« 

24. Peteicola robusta, Sow. 

Froc. Zool. Soc. 1834, p. 4,7.— Sow. Tlies. Conch, part xv. p. 775, 
no. 14 ; pi. cbcvi. f. 16, 17.— Miiller, Syn. Moll. p. 229, no. 9.— 
PhiUppi in Zeit. fib' Malac. 1848, p. 163, no. 33, quasi sp. 
nov. :.edidit Besh. in B. M. Cat. Veneridce, &c. p. 210, no. 10. 

? = P. bulbosa, Gould's plates, ms. 

The name of this shell, which was well described by Sow. in 
1834, was appropriated by Phdippi in his 3;'(^ Centuiy of new 
shells for a supposed new species ; which turns out fortmiately 
to be a small si^ecimcn of Sow.'s species, and thus confusion of 
synonymy is unexpectedly avoided. Deshaj'es has imfortu- 



18 



MAZATLAN BIVALVES 



nately copied this description into liis Cat. Ten. B. M., instead 
of the original one. The yonng is generally (so PhU.) "sub- 
globosa, alba," and occasionally shews the radiating ribs "pos- 
tice distantibns" ; the bifidity of the anterior tooth in the left 
valve is rarely seen in the adult. When extremely young, the 
shell is irregularly rugose, but not shagreened : the apex is then 
moderately prominent : the rugosities soon fall into regular 
ribs dividing between the posterior and ventral parts ; the 
interspaces are finely rugose. Very soon the apex disappears, 
and a large space round becomes eroded. The shell which has 
previously been white, assumes various shades of orange, lilac 
and chocolate, develoijing at last into a lustrous brown, especi- 
ally at the muscular imi^ressions. Meanwhile the characteristic 
concave decussating striae appear between the ribs ; and on the 
posterior ribs (which are generally closer than the ventral but 
not so close as the anterior ones) are gathered up into knobs. 
The anterior ventral part is generally much swoUen, often with 
a concave margin between that and the posterior end, which is 
not unfrequently much produced, flattened, and even bent up- 
wards. The short, semi-internal Ugament (somewhat resembling 
Ungulina) is tiu'ned up spirally round the umbos, as in Chamse, &c. 

The burrow is shaped as the sheU, with a rising corresponding 
with its posterior ventral depression, and withoiit any siphon 
gallery . The opening is oval, irregular, and always exposes 
to view the extremities of both valves. Mr. Darbishire has 
one foiu'th of a Spoudylus valve, with no fewer than eleven 
Petricolfe projecting their extremities. The interior of the 
burrow is irregular and rough. One of the Chama?, here- 
inafter enumerated, displays a Petricola, which, having bored 
through the Chama and come to the rock, prefei-red flat- 
tening its own valve to undertaking the unexpected labour. 
This creature, having no i)ower to move round in its hole, is 
frequently bored into by its neighbours. A pedal scar is occa- 
sionally seen towards the anterior end, sometimes deep, with 
dried horny substance as in Parapholas. 

The largest specimen measures Zo?!5r. * 87, lat. 1*22, alt. '7S, 
The most oval „ " -63, „ '78, „ -52, 

The smallest „ „ '06, „ "OS, „ -04. 

Hah. — In rocks, 6 — 11 fm., Panama and Isle Muerte, CtMning. — 
Jun. in Avicula margaritifera, Panama, JS. B. Philippi. — 
Mazatlan : in Spondylus Lamarkii, not unconmion : very 
rare in Chama. Vei-y young shells are rarely met with ; 



MAZATLAN BIVALVES 19 

perhaps from living near the outside, and therefore being 
easily washed out ; L'-pool Sf Havre Coll.* 

Tablet 65, 4 young valves. — 66, 2 pairs, 2 valves, adolescent. — 
67, 2 pairs, adult. — 68, 2 pairs bored into and distorted. — 69, 
specimens of dried foot. — A burrow may be seen in ?36, and a 
specimen in situ among the Chamse. 



25. Peteicola venteicosa, Desk. 

Proc. Zool. Soc. 1853, ?ubi.— 5. M. Cat. Ven. p. 214, no. 22. 
= (teste Soiv.) P. denticulata, Soiv. Proc. Zool. Soc, 1834, p. 46. — 

Soio. Thes. Conch, part xv. p. 773, pi. clxvi. f. 6, 1.—B. M. 

Cat. B'Orh. Moll. p. 64, no. 564.— J5. M. Cat. Ven., p. 213. 

no. 21. 

This shell agrees ■udth the description of P, ventricosa better 
than with that of P. denticulata, and must rank with that species 
if they prove distinct. If they are identical, as Sow. supposes, 
his name, though not so expressive, has priority. It takes 
both the elongated and abbreviated forms. Lonq. "26, lat. "36, 
alt. -23. 

Hab. — (P. denticulata) Payta (Peru) in hard clay and stones at 
low water, Cuming. — Arica, D'Orhigny. — (Var. abbreviata) 
Isle Plata, Cuming. — Payta D'Orbigny. — (P. ventricosa) 
Gulf of California, Mus. Cuming. — Mazatlan : burro-R-ing in 
Strombus galea, extremely rare, Havre Col. — Eeceived with 
other shells from the West Indies, P. P. C. 
Tablet 70 contains 2 opposite valves. 

26. Peteicola , sp. ind. 

Tablet 71 contains a rugose fragment, apparently not identi- 
cal with any published species from the W. American coast. 
Hab. — Mazatlan : in Spondylus Lamarckii : L'x>ool Col. 

* I strongly suspect that this species is also found on the W. African coast. I 
have a valve, received from the Bristol Institution where it had been before they 
had a single sheU from the West Coast of America that I know of, and before 
Cuming's discoveries there. At that time there was plenty of trade between 
Bristol and Africa ; and I believe the species came out of Ostrea iridescens of 
which they had a large stock. Vide remarks on [that sp. and Placunanomia. If 
P. typica, Sow. Thes. Conch. No. 13. does not differ from robusta more than is 
there stated, it is probably the same species, from St, Thomas, W. Indies. 



20 MAZATLAN BIVALVES 

Genus EUPELLAEIA, Bellevue. 

Eupellaria, Fleuriau de Bellevm, 1802, Bullet. Soc. Philom. 

nr. 62.— Philippi, Randh. d. Conch. Sf Mai. in loco. 
G-astrana, ScJmm. 1817. 
Venerupis, Lam. 19,1%.— Besh. B. M. Cat. Fen. p. 189. 

27. Eupellaria lingua-felis, n. s. 

V. t. subcyUndricd, alba, tenuissime et dense granulosa, suh- 
diapkand ; granulis irregulariter confeHis, I'meis radiantibus 
confluentibus ; circa umbones IcBvigatd, liris comeiitricis ititer- 
r lipid ; strias incrementi nonnunquam monstrante ; lumdd in- 
distinctd; umbonibus p)rominentibios ; intuspolitd, margine plana ; 
impressiones musculares vix monstrante, sinu pallii tnagno, 
clrculari ; dentibus 3—2, quaruni una bifida ; nymphis et liga- 
mento parvis ; dentibus et nympMs supra lineam cardinalem 
intus prominentibus. 

Shell in sliape like P. mirabilis, DesJi., wLich represents it on 
the Californiau coast ; but recognized at once by its surface 
which preseuts, under the microscope, most delicate granula- 
tions somewhat hke Telliua lingua-felis, whence its name. 

Smallest specimen measiu-es long. '025, lat. '03, alt. '02, 

Largest „ „ „ "H, » "16, „ '09. 

JTa/j.— Mazatlan ; in Chamse and Spondylus Lamarckii, nesthug 

in burrows, rare ; L'pool (Sf Havre Coll. 

Tablet 72 contams 5 specimens in various stages of growth. 

28. EUPELLAEIA EXAEATA, n. S. 

J", t. forma " Linguce-felis" simili, umbonibusque^ ut in specie 

Hid : sed radiatim tenue sulcata, alhicante, rufo-fulvo macu- 

lata : fortiori, nee intus polifd : dentibus 3-3, quarum tt-na 

bifida, extantibus : epidermide tenui, fused. 

Shell in size and shape like V. lingua-felis, but wanting the 

granulose texture, and covered (except at the lunbos, which are 

i-oncentrically striated) with very fiue rather ii-regular radiating 

ribs, as in Potricola, interrupted occasionally by lines of growth. 

Colour whitish, stained with chocolate. Hinge teeth projectmg 

upwards, not sideways as in the last. Pallial smus large, well 

rounded. These shells have the general appearance of Naramo, 

Gray. 



MAZATLAN BIVALVES 21 

Smallest specimen, long. '018, lat. '03, alt. '015, 
Largest „ „ "IS, „ -21, „ -12. 

Hah. — Mazatlan ; a small colony were found nestled, and 
greatljr incommoding each otker, in empty Balani on Mnrex 
princeps : Havre Col. 

Tablet 73 contains 1 specimen in situ, in Balanus ; 3 others 
of different ages. 

29. EupELLAEiA , sp. ind. 

Tablet 74 contains a fragment resembling R. foliacea. Z>e-.sV/. 
Mazatlan ; with strong radiating ribs crossed by erect and beau- 
tifully imdulated laminse. The sculpture smoothes off at the 
hinge margin. 
Hah. — Mazatlan ; from the back of a Spondylus Lamarclvii ; 



Upool Col. 



Family COEBULIDiE. 
Genus COEBULA, Bmu. 



30. COKBULA BICAEINATA, SoiV. 

Fmc. Zool. Soc. 1833, p. 35.— Miill. Si/n. Test. Viv. p. 229.— 

Rve. Conch. Ic. 1844, pi. 3. f 23.— Hani, in TFood's Svpi)l. 

Ind. Test. pi. 12, f 31.— Hani. Descr. Cat. p. 46.-5. 3L Cat. 
. D'Ori. ilio?/. p. 70, no. 619. 

Shell extremely swollen, the valves nearly equal, sometimes 
one a little overlapping the other at the posterior A^entral margin. 
Epidennis thin over the body, thick over the margins of the 
valves. Irregidarly concentrically striated over the surface, 
very finely between the posterior keels : umboual portion 
smooth. Within, ligament affixed to the smaller tooth : pos- 
terior muscidar scar rounded, on a projecting support : a 
smaller one behind : anterior scar oblong. Pallial line simple. 
In the 3 specimens which alone I have had an opportimity of 
examining, which are qiute fresh, I cannot detect any pallial 
sinus. Those who have plenty of Corbulai woidd do well to 
examine their interiors, which are not generally noticed in the 
descriptions. They are either very rare at Mazatlan, or have 
escaped detection, scarcely a dozen si^ecimens having been 
foimd of all the species. Long. 2' 7, lat. '3iS, alt. '28. 
Hah. — In sandy mud, 7 — 17 fm., Panama, EealLlejos, Caraecas, 

St. Elena, Cuming. — West Columbia, Hanley, Jay. — Ecuador, 



22 MAZATLAN BIVALVES 

S. Eleua, UOrUgjiy. — Panama, common, C. B. Adams. — 
Mazatlan ; extremely rare ; L'pool Col. 
Tablet 75 contains 1 specimen, laid open. 

31. COKBULA BIBADIATA, SotV. 

Proc. Zool. Soc. 1833, p. Bo.—MnU. Si/ii. Test. Viv. p. 230.- 

Sve. Conch. Ic. pi. 1. f. S.—Hanl. Siippl. Wood's Ind. Test. 

pi. 10. f. b\.—Hanl. Bescr. Cat. p. 47.— -B. M. Cat. D'Orb. 

Moll. p. 70. no. 620. 

Shell witli valves nearly equal, ventral margin flattened, 
posteriorly rather widely overlapping. Epidermis scarcely 
visible except at the margin, vrhere it is, as usual, thick. Within, 
purplish white, ligament attached to larger tooth. Posterior 
muscular scar strongly marked, partly projecting, partly indent- 
ed, siibcircular, -with the little one behind coalescent. Anterior 
scar i^ear-shaped. PaUial line irregidar ; sinus very small. 
Long. '33, lat. "52, alt. "26. 
JSTfli.— Mud and sand, 3-6 fms.. Chiriqui : 7 fin., in Bay of Carac- 

cas: Cm w/w^r.— Ecuador; Chiriqui: D'Orhigny. — W.Columbia. 

Jay. — Panama, very rare. C. B. Adams. — Grulf of California. 

Mus. Cuming.— Mazatlan ; extremely rare : L'pool Col. 

Tablet 76 contains the only specimen fouiul. in extremely 
fine condition, flattened. 

32. CoKBULA PrSTUJLOSA, ». S. 

C. t. parvd, alba, ohesa, solidd, postice produetd, tntncatd, 
antiee rotimdatd, ah umhonibics postice suhangiilatd ; valvd 
minore plus minusve inclausd, maxime in iiiargine ventrali ad 
jjosticum decurrente, arcuatd : valvis concentrice liratis, liris 
ii'vegulanhus, suhrotundatis : epidennide tenui, ad margineni 
crassa : lineis ex ill i m i s r a d i a n tihiis p u s t u laru m 
in i n i m a r it m r epletis : iimbonibus Icevigatis, 

Shell small, white, subglobose, produced posteriorly, with 
the valves overlapping, bent at the posterior end of the ventral 
margiii ; with irregidar, somewhat rounded concentric ridges, 
crossed by the finest radiating lines, which imder the microscope 
are found to consist of rows of minute pustides, probably 
formed in the epidermis, which is extremely thin over the body 
of the shell, coarse rovmd the margm, and at the posterior side, 
which is rather angidated. 
Mr. Cuming's specimen measures long. '16, lat. '24, alt. 14, 
The Mazatlan specimen ., „ "U, „ '16, „ "11, 



MAZATLAN BIVALVES 23 

Hixb. — Pauama and St. Bias, 33 fm. B. B. Sinds, Mus. Ctun- 
ing. — Mazatlan : one small pair nestling in Spondylus, and 
1 valve in Chamge, Ij'pool Col. 

There is no doubt that the Mazatlan shell is the same as 
Mr. Cuming's beautiful specimen, hitherto undescribed. Tablet 
77 contains the perfect specimen ; I reserve the valve. 



33. CoRBULA PoVULATA, SoiC. 

Proc. Zool. Soc. 1833, p. 35, m.—Mull. Styn. Test. Viv. p. 230.— 

Rve. Conch. Ic. pi. 1. f. 7. — Hani, in Suppl. Wood's Ind. Test. 

pi. 10, f. 52.— Sf<«7. Bescr. Cat. -p. 4.7.— B. M. Cat. BOrh. 

Moll. p. 70, no. 622. 

Tablet 78 contains 1 flat dead valve of regular oval shape 
shghtly produced anteriorly, and very^ finely striated concen- 
trically, which may belong to this species. 
Hab. — In sandy mud, 7 — 17 fm. Xipixapi, and Bays of Montijo 

and Caraccas, Cuming.* — Ecuador: Xipisapi, BOrhicjny. — 

Taboga, very rare but large, C. B. Adams. — Mazatlan : 

one valve, B'pool Col. 

34. CoHBULA , sp. ind. 

Tablet 79 contains a fragment of what must be when perfect 
a most beautiful and remarkable species. It is extremely thiii, 
white, translucent, with a veiy sharp diagonal posterior keel, 
and another close to the margin. Umbos very near the anterior 
end. Shell smooth near the umbos ; afterwards with w aved 
concentric ridges ; posterior part with deep pits at a sharp 
angle -n-ith the ridges. The whole shell with radiating rows of 
dots (probably epidermal) as in C. piistulosa. Inside a stout, 
somewhat conical tooth in each valve, with corresponding pit. 
Interior surface verj^ finel.y rugose. Mr. Hanley found a mucli 
more perfect specimen, which was most unfortunately crushed 
in transmission by the jjost. 
Bah. — Mazatlan ; from Spondylus Lamarckii ; Bpool Sf Havre 

Coll. 

* Mr. Reeve further states "A few odd vnlves of this species werejhi'.ml in 
yir. Ciiniiiiij on the sand^ at Keal Llejos and Mazatlan." In reference liowevor 
to this last locality, Mr. Cuming states that his extreme point north, along tht 
West American coast, was Conchagua, Bay of St. Carlos (or Fonseca) : about 13 " 
N. L. In all cases therefore where he is cited as the original collector at places 
north of this, the authority must be regarded as "Museum Cuming." 



24 MAZATLAS BIA'ALVES 



Genus SPH^]S"IA, Turton. 

For Mouogi'apli of tlii^ genus, with, amended generic characters, 
see A. Adams in Proc. Zool. Soc. 1850, p. 86. See also Forbes 
.1' mini. Br. Mol. vol. 1. p. 189—193 -.—ClarhBr. Mar. Test, 
Moll p. 150. 



35. Sph^nia fkagilis, n. s. 

S. animali in cryptis latihulante, ergo vane distorto ; testa 
parvd, tenui, subnacreu, vix rugose striata; epidermidefusco- 
virente copiose indutd, rugarum increscentium concentricarum 
plena, postice in siphone longd porrecta : parte 2^ost>cd plus 
minusve suhcarinatd ; valvd sinistra dente ligamentum ferente, 
plus minusve seu prolongatd seu extante; dextrd alveo conveniente. 
nonnunquam denticulo suhextante : imjjressionihus muscularibus 
suhrotundutis, sinu pallii lato, rotundato, liaud alto. 

It is siu-prising liow miicli of the very minute description of 
S. Binghanii given in Furhes Sf Sanl. Br. Moll. i. 191-2, applies 
exactly to iadividuals of this species. Indeed, if young speci- 
mens of the two were mixed together, I should hardly know 
any sulhcient ground of specific distiuction, except ui the texture 
which is more nacreous, and the paUial siaus which is broad, 
though shallow. The yoimg shells can sometimes be told from 
those of Saxicava arctica only by the lunge, as in Binghami ; 
and there is often seen the little denticle by the ligiunent pit 
noticed by Turton, not Hanley, and conspicuous in young 
shells of Spha-nia Binghami in ray possession, nestling in cre- 
vices of limestone dredged ofl' Weymouth. Like other nestlers 
(unlike the true borers, which are moderately constant in form) 
it is extremely irregular. ]\Iany well characterized species 
might be made out of extreme forms ; but unfortimately 
for the lovers of multiplication, individuals were siiiHciently 
numerous to supply many connecting links. The normal state 
appears to be not very inaHiuUateral and tolerably ^\•ell roimded : 
the shell is then shaped somewhat like Psammobia : but it is 
generally more or less produced, when the posterior portion 
becomes marked olf by an angle, in very long specimens 
amounting to a keel, sometunes with a trace of a doidile one. 
Wlien it lives in dead Balani &c., it becomes very short, inflated 
and gibbous, resembling Corbula or sometimes Neajra. The 
ligamental plate then becomes narrow, projecting andsinuated. 
more like the tooth of Mya. These variations are seen in the 



MAZATLAN BIVALVES 25 

young as much as in the adult sliells. A very small specimen was 
found to contain a minute young one. Specimens as broad as 
'2 in. are very uncommon. One specimen was found having its 
siphon pipe projecting nearly half the breadth beyond the shell. 



Smallest specimen measures 


long. 


•02, lat. 


•03 alt. 


•015 


Elongated „ „ 


,, 


•03, „ 


■1, » 


•02. 


Oval 


,, 


•2, „ 


•26, „ 


•14. 


Largest „ „ 


,, 


•18, „ 


•31, „ 


•14 



Hah. — Mazatlan : inhabiting the burrows of worms and Mol- 
lusks in Chamse and Spondylus Lamarckii; also in dead Balani 
on Strombus galea ; not uncommon ; L'pool Sf Havre Coll. 

Tablet 80 contains 22 valves and 1 pair, jim. of various 
shapes. — 81, a pair of regular shape with yoimg miUipore grow- 
ing on ; i^aii* with long siphon pipe ; valve with internal lamina ; 
5 broken valves shewing hinge sti-ucture, &c. — 82, the largest 
specimen, from hole of Lithodomus caudigerus in Strombus 
galea ; a Balanus with oval Sphsenia taken from within. 



We insert here a notice of a unique shell described by A. 
Adams in the An. Nat. Hist. 1854, ix 418, under the name of 
Tyleria fragilis. Though named in honour of ]Mr. Tyler, he had 
it in his possession a considerable time without knowing of any 
thing remarkable attendiug it. I have taken several journeys 
to Liverpool and made enquiries in London, in hopes of seeing 
it, without success : but, as evidence that it is not mythical, I 
deposit, on Tablet 83, di*awings made by Mr. Sowerby and 
most kindly placed at my disposal by H. Adams, Esq. It 
is possible that it is a deformed shell. I have occasion- 
ally noticed valves of Sph. fragdis with a tendency towards 
the same crenation at the posterior end, apparently through 
irritation of sand, &c. ; also with the pallial line bi-oken up. 
Mr. Tj'ler states that he found it in a burrow in the large 
Spondylus from Mazatlan ; L'pool Col. 



Aug. 1855. 



26 mazatlan bivalves 

Family PANDOEID^, 
Genus LYONSIA, Turton. 
Syn.. Mytilimeria, Conr. Magdala, Leach. 

36. LyoiS'Sia PiCTA, Soto. 

Proc. Zool. Soc. 1834, p. 88.-/5. M. Cat. D'Orh. Moll. p. 58. 
no. 506. 

? = L. cuneata, D'Orb. — B. 31. Cat. loc. cit. 
?=ABatiiia cuneata, Gray, Spic. Zool. vi. 1828. 

One perfect specimen of this remarkable sliell was found by 
Master F.Archer, "burrowing" [? nestling] in Spondjlus, and 
now graces his father's collection. It gapes almost as much as 
Gasti'ochsena, and displays a large ossicle ^vithin. The lunular 
portion is deeply excavated, and the posterior verj- greatly 
l^roduced. Epidermis rugose, occasionally displaj'ing fine radi- 
ating ridges. Tlie growth is irregular, as usual in nestlers. The 
amount of gape varies considerably in j\Ir. Cuming's specimens. 
Size of ]Mr. Archer's specimen: long. '8, lat. 1'2, alt. MM'. 

The few fragments I found are known at once by the pecuhar 
microscopic structure, described by Dr. W. B. Carpenter in 
Rejy. Br. Assoc. 1847, p. 105. 

Hah. — ^Attached to particles of sand in 11 fm.. Isl. Muerte. 

Cuming. — Vancouver's Island. Col. Cuming. — Mazatlan : 

nestling in Chama\ &c., extremely rare : L'pool Col. — ? Arica. 

(Peru,) jyOrhigny. — The South Temperate analogue appears 

to bo L. Patagonica, "^S'orthern Patagonia, San Bias." 

D'Orh. — The "W. Indian analogue is L. plicata. Gray. 

Tablet 84 contains a perfect young specimen, just beginning 

its gape, and displaying the radiating stria? ; also a fragment of 

an older one, shewing the hinge. — 85, drawings of Mr. Archer's 

specimen, made by Master John Jackson. 



Another species of Lyousia, allied to A. cuneata, G-ray, has 
been brought from Mazatlan : but as aU the fragments even, in 
the L'])oolCol., clearly belonged to L. picta, I liave not ventured 
to include it. Like L. picta, it ^ aries extremely in shape and 
gape : the latter being generally small, sometimes wanting. 
Textiu'c smooth, cxtremelj' thin, white, glossy. 



mazatlan bivalves 27 

Family SOLECHRTID^. 
Genus SOLECUETUS, Blainv. 

37. SoLECrBTUS AFFINIS, C B. Ad. 
C. B. Ad. Pan. Shells, p. 300, no. 510. 

Tlie autlior of tliis species does not point out wlierein it dif- 
fers from its Atlantic analogue, S. Caribseus. The similarities are 
evident. 

The smallest specimen measures long. "S, lat. "84, alt. "14, 

The largest ,, „ „ '77, „ 2-4, „ -48. 

J5a7;.— Panama, verj' rare, C. B. ^c?.— Mazatlan : not common : 

L'pool Col. 

Tablet 86 contains 4 yoimg specimens.— 87, 3 adult.— 88, 3, 
lighter colour.— 89, 3 with thinner epidermis.* 

88. SoLECtJETUS POLITUS, 71. S. 

S. t. forma " S. ajfini " simiU, sed suhtransliicidA, violacea, extus 
linea fused et lineis albieantibus nonmilUs radiata ; epider- 
mide politissimd, fusco-ruhente : intiis nymphis elongatis, 
denticulis 1-2 acutis, sinupalUi versus umhones maxiine arcuato ; 
callositate ah umbonibus , lined fused exteriore con- 
veniente, subexpressd decurrente . 

Known at once by the brownish violet colour, glossy epider- 
mis, and dark ray corresponding with a slightly prominent 
ridge within. In this respect alone it resembles Machsera. In 
the pallial sinus, S. affinis is intermediate between politus and 
violascens : in colour, S. violascens is intermediate : in the pro- 
longation of the nj-mpha?, S. politiis. This species displays 2 
small distinct muscular impressions between the unilio and the 
anterior adductor, which is oblong, but well defined : in S. vio- 
lascens, it tapers off irregularly, im^iting witli these two : in S. 
aifinis it is irregular, not tapering, uniting witli the others which 
are also irregular. The largest specimen measures long. '48, 
lat. 1-45, alt. 23. 
Sab. — Mazatlan : 4 specimens found with affinis : L'pool Col. 

Tablet 90 contains the most characteristic specimen. 

• Lower down the coast was found a large spepimen which appears a distinct 
epecies, and I therefore append a description, and deposit the shell in the B. M. 
Col. 

SoLECUETUa VIOLASCENS. S. t. " S. affini" simili, sed majore, solida, violas- 
cente, rugis epidermidis tenuioribus ; nymphis elongatis, sinu pallii versus uni- 
bonea minus arcuato. Long -95, lat. 3 '33, alt. "56.— 7/<z6. S. W, Mexico, P. P. C. 



28 MAZATLAN BIVALVES 

39. PSoLEcrETUS , sj). ind. 

Tablet 91 contains a fragment very flat, wliite, thins with 
irregular very fine strife, shewing within as well as without. 
Hah. — Mazatlan : in Spondylus washings ; I! pool Col. 

Family TELLINID^. 

aENUS SEMELE, Schum. 
S//)f. Aniphidesma, Lam. 

4*1 Semele peoxima, C. B. Ad. 

Amphidesma proximum, C. JB. Ad. Pan. Shells, p. 289, no. 487. 
Aniphidesma proxima, (sc. -um) Rve. Conch. Ic. Amph. pi. 3, 

f. 20. 

So much does this species vary in outline, and so closely do 
some forms approximate to S. elliptica, that it is still an open 
question whether C. B. Adams did right in separating it. The 
eolour is typically orange within, and the iDallial portion is 
punctured. 
Kab. — Panama, rare, C. B. Adams. — Mazatlan ; common ; 

L'pool Col. 

Smallest specimen measures long. '(Vl, lat. '05. alt. '02, 

Larsest „ .. ,. 2-36, „ 2 b. ., 1-23, 

Transverse „ „ „ 2-03, „ 2-36, „ I'lT. 

Tablet 92 contains a pan- and a valve, extremely young, which 
probaljly belong to tliis species, though there are lateral teeth 
.slightly developed. — 93. 5 specimens, normal state. — 94., 5 speci- 
mens more oblong.— 95, 3 specimens very regularly roimded. — 
96, 3 specimens, very transvei"se. — 97, 4 yoimg specimens, with 
very light epidermis. — 98, 2 specimens shewing interior, — 99, 2 
pairs and a valve, deformed in growth. 

41. Sejwele Pvenusta, A. Adams. 

Proc. Zool. Soe. 1853, p. 96. 

Aniphidesma veuusta [sc.-um] Bve., Conch. Ic. Amph. sp. 3. 

pi". 1, f. 3. 

Tablet 100 contains a young valve which agrees in the main 
with this species. The concentric ridges are not developed, 



MAZATLAK BIVALVES 29 

and here and there a few radiating stria? appear under the 
microscope. Loyig. "28, lat, '34, alt. "13. 
Hah. — W. Columbia, Mus. Cum. — Mazatlan, 2 valves ; L'pool 
Col. 

Genus CUMINGIA, Sow. 

Por amended generic character, v. Froc. Zool. Soc. 1850, p. 24. 
The shell differs essentially from Semele, in its lateral teeth 
and ligamental spoon. The animal also differs, as from Syndos- 
mya, in its irregtdar cryptophilic habits. The species here 
enumerated are given under protest. Cumingise are nestlers, 
like Sphfenia and Sasicava, and therefore subject to every possi- 
ble variation of form. They are fond of growing in company, 
and squeeze each other up into the queerest shapes. And yet 
the published specific characters are maiuly drawn from the 
shape alone, with the very variable markings. Almost aU the 
species are variously ribbed concentrically, with minute radiat- 
ing decussations. The characters of the hinge may be more 
constant; but alas! neither Sow. nor A. Ad. even allude to them. 
I have examined about 60 specimens froni Mazatlan which 
might easily be distributed into 20 species, with as good char- 
acters as those which distinguish Sow.'s species. C. B. Adams 
distributed his 14 specimens mto 6 species, but mercifidly for- 
bore to describe the 4 supposed new ones, on the ground that 
they are "probably somewhat variable." Locality also is no 
great help : the Atlantic and Pacific, the N. and S. Temperate 
species not differing from each other so much as each species 
may -nithin itself. Mr. Cuming has most kindly come to my 
rescue, and named the principal specimens according to his 
types : the smaller ones, in which there is least distortion, I 
have mapped out as weU as the microscope woixld allow me. 
To do the work satisfactorily would require a very large niun- 
ber of individuals from various localities. The Mazatlan stock 
was large enough to confuse, not to help. 

42. CUMINGIA LAMELLOSA, SoW. 

Proc. Zool. Soc. 1833, p. 34. 

Lavignon lamellosa, B. M. Cat. D'Orh. Moll, p. 59, no. 518. 

Lamella; extremely irregular, sometimes scarcely shewmg 
till the creature is nearly adidt. Radiating stria; not strongly 
marked. PaUial sinus moderate : hinge teeth moderate, pos- 
terior lateral tooth the longest. 



30 MAZATLAN BIVALVES 

Smallest specimen measures long. '04, lat. '06, alt. "02. 

Largest „ „ „ '49, '72, 'U. 

Tablet 101 contains 3 young valves. — 102, tlie largest (imper- 
fect) specimen. — 103, a C. lamellosa, wHch had establislied 
itself within the empty remains of a Petr. robusta, which had 
itself gone to dwell inside the skeleton of a deceased relative 
which had originally constructed the burrow.* 



The form coarctata was found by Mr. Hanley in Spondylus 
Lamarckii ; Havre Col. 

43. CUMINGIA TEIGONULAEIS, SoiV. 

Proc. Zool. Soc. 1833, p. ^o.—Rve. Con^h. S^sf. pi. 49, f 2.— 

C. B. Ad. Pan. Shells, p. 288, no. 480. 
Laviguon trigonularis, G-ray. B. M. Cat. B'Orb. Moll. p. 59, 

no. 519. 

Tolerably well distinguished by the great projection of the 
ligamental spoon and liinge teeth. The laterals are very short, 
trimcated, and of nearly equal length. PaUial sinus ver\' large. 
Decussating striaj well developed. N. B. The muscular scars 
often vaiy in shape with the distortions of the shell. The 
largest specimen found measures long, 'o, lat. '62, alt. "32. 
JTal). — St. Elena : among stones in deep water, Cuming. — 

Ecuador ; St. Elena, D' Orhigni/. — Panama, very rare, C. B. 

Adams. — Mazatlan : nestling in burrows iu Spondylus Lam- 
arckii : very rare ; L'pool Sf Havre Coll. 

Tablet 104 contains 1 perfect and 3 broken specimens, of 
various ages. 

\'i. CvMiNGiA Califobnica, Conr. 

Journ. Ac. ^Tat. Sc. Phil. IS , p. 
Teeth and pallial sinus intermediate between C- lamellosa and 

C. trigomdaris. Anterior side generally swollen. The largest 

specimen found measures long. "33, lat. "52, alt. "22. 

7/„/;._XJpper Cahfornia, i\'« //«//.— Mazatlan ; nestling in bur- 
rows iu Spondylus Lamarckii, very rare ; L'pool Col. 
Tablet 105 contains 1 young, and 2 adult specimens. 

* So I ha\e, in limestone from WejTJiouth Bay, Sphffinia Binghami nestling in 
the tube of a Gastrochicnn modiolina which had been formed by soldering 
together portions of a Thracia distorts through which it had burrowed. 



MAZATLAN BIVALVES 31 

45. CcMiNGiA , sp. ind. 

Messrs. Cuming and Hanley who possess perfect specimens 
of this shell, regard it as a new speeies. Let those dest-ribe it 
however who understand the specific marks in this genus. The 
few valves found were all toothless. The pit and tooth marks 
are extremely small ; shell small, deHcate, flat, triangular. It 
closely resembles C. striata, A. Ad. Pruc. Zool, Soc. 1850, p. 25, 
and has affinities with Syndosmya tenuis. Long. '3, lat. '38, 
alt. -15. 
Hah. — California, j\fus. Cuming. — In Chama^, extremely rare ; 

Mazatlan ; L'pool Sf Havre Coll. 

Tablet 106 contains 2 valves. 



Tablet 107 contains 1 of three small specrmens which I can- 
not identify with existing species. The form is very regidar, 
like C. Cleryi, A. Ad. but the shell is convex, and marked as in 
the t>T)ical species. The teeth bear most resemblance to 
C. Calif ornica, Con>'. Long. '18, lat. '23, alt. "11. 
Hob. — Mazatlan : in Spondylus Lamarckii, nestling in bur- 
rows : extremely rare ; L'lwol Col. 



Genits SAJN^GTJINOLAEIA, Lam. 

46. Saxguinolaeia puepueea, Desk. 

Prur. Zool. Soc. 1854, p. 346, no. 137. 

Compare Sangiiinolaria tellinoides, A. Adams in Pi'oc. Zool. 
Soc, 1849, p. 170 : pi. 6, f. 6. 

? = TeIlina (non Strigilla) miniata, Gould's Plates, ms. 

This shell is extremely like S. tellinoides, but differs in texture, 
"one being thin and delicate, the other coarse and strong in 
comparison," Cuming. Gould's description may prove his shell 
to be different. It seems abnost as much aTellina as T.rufcscens. 
It is the Pacific analogue of S. rosea. Only 2 specimens were 
found in the L'pool Col. (Mus. Archer & B. M.) ; but as several 
specimens were in the London shops, it is probable that more 
were sent in the Havre Col. Long. 1'07, lat. 1"73, alt. "47. 
Hah. — Mazatlan : extremely rare ; L'pool Col. 

Tablet 108 contains 1 specimen. 



32 MAZATIAN BIVALVES 

Genus TELLINA, Lin. 

47. Tellina eufescens, Clienin. 

Chemn. vi. p. 105. 1. 11. f. 97 —Schroeier, Einl. t. 3, p. 5. no. 11.— 

Diho. JDesc. Cat. vol. i. p. 9,h.—Knorr, vol. vi. t. 12, f. 1.— 

Saod. in Sow. Thes. Conch, vol. i. p. 307, pi. 63, f. 213. 
= T. operculata, Gmel. p. 3235, no. 32, Tar. exc.—Lam. ed. 

Besh. 1836, vol. 6, p. 192.— TToocZ'.? Ind. Test. p. 19, no. 37.— 

Rani. Descr. Cat. p, 62, t. 4, f. 37. 
= T. cmenta, Solander, ms.— Portland Cat. p. 58, lot 1360. 
= T. opercularis Sow. Gen. no. 31, f. l.—Desk. Enc. Meth. 

vers t. 3, p. 1010, no. 9. 

This sliell must not be confounded witli T. rufescens of Gmel. 
which = Venus decussata, var ; nor with the too-similarly named 
T. rubescens ofSanl, a shell found as far north as S. W. Mexico, 
(P. P. C.J but not yet obtained from Mazatlan. T. rufescens 
is known at once hy its large size, red colom- (often banded 
with whitish,) and greatly produced beak. Lower valve pro- 
jecting, as in Corbula, and displaying faint radiating lines, 
which are generally obsolete on the upper. It gapes at both 
ends, and nearly approaches Sanguinolaria. Long. 1'73, lat. 
3-17, alt. -77. 
^«i.— Coasts of Brazd, Humphreys.— Caribba?an Sea, Lam. 

"Cab. de M. Dufreue."— (Lidian Ocean, Wood.)— Tumbez, 
(Peru,) in soft, sandy mud, 5 fm., Cuming. Mazatlan ; rare ; 

L'pool Sf Havre Coll. 

The authorities for the Atlantic Ocean do not appear satis- 
factory. On the other hand, the shell being known to the old 
writers is in favour of its having been brought from the West 
Indian seas. 

Tablet 109 contains 1 small specunen from the L'pool Col, 
and 1 large one from the Havre Col. in which it was less un- 
common. 

48. Tellina BEODERini, Desk. ms. (teste Cum.) 

Compare TeUinides purpureus, Brod. Sf Soto. Zool. Juurn. 
vol. iv. p. ?,m.—Zool. Beech. Voy. p. 153, pi. 42. f. 2.— = Tel- 
lina ])urpurascens, Llanl. Bescr. Cat. p. 74, suppl. pL 9, f. 18 : 
do. in Sow. TJu's. Conch, p. 295, no. 141, pi. 62, f. 194. 



MAZATLAN BIVALVES 33 

Shell closely resembling T. purpurea ; from Real Llejos, 
Cwmincj. It differs from the plate in Beech. Voy. in having, 
the umbos less pointed and the teeth smaller. The surface is 
crowded with extremely close concentric strise, decussated 
(except on the fold area) by very fine radiating lines, which 
become obsolete, in one valve only, on the ventral portion. 
The fold area is nearly smooth (except lines of growth) on one 
valve ; on the other, with rather sharp raised ridges, carrying 
on generally every other one of the concentric stria;. Epiderw 
mis light brown, very thin, coarser on the fold area. The 
species much resembles (though smaller) T. princeps, a valve 
of which was sent from S. AV. Mexico, (P. P C.) It gapes on 
each side, and might almost pass for a Sauguinolaria, but for 
its flatness. Long. I'lS, lat. 2-12, alt. -31. 
Sab. — Mazatlan, 3 specimens (Mus. Archer, Darbishire. B. M.) 

Zj'pool Col. 

Tablet 110 contains one si^ecimen. 

49. Tellina ?? Mazatlanica, Desk. 

T. Mazatlandica, Proc. Zool. Soe. 1854, p. 359. 

Tablet 111 contains a minute fragment which may be the 
young of this species, though the characters of the hinge are 
somewhat different. The Cumingian tj^ie measures long. '79, 
lat. 1-3, alt. -32. 

Hah. — Mazatlan : Col. Cuming. — ?? Do. in Spondylus washings, 
JJpool Col. 



50. Tellina Dombei, Hani, 

Proc. Zool. Soc. 1844, p. 144. — Hani, in Soio. Thes. Conch. 

p. 323.— C. B. Ad. Pan. Shells, p. 282, no. 4r,4. 

A plain, white, oblong shell, much swollen and produced 
anteriorly. Long. I'l, lat. 1'45, alt. "5. 
Hah — Panama, in sandy mud, 12 fm. Cuming. — Panama, rare, 

C. B. Ad. — Mazatlan, 2 specimens, L'pool Col. 

Tablet 112 contains one specimen. 



34 MAZATLAN BIVALVES 

51. Tellina feltx, Sard. 

Proc. Zool. Soc. 1844, p. 71. — Hani, in Sow. Thes. Conch, vol. i. 
p 281 : pi. 58, f. 52.— C. B. Ad. Pan. Shells, p. 282. 

Closely resembling a "West Indian species in form and colour : 
Hani, compares it -vritli T. donacina. Long. '43, lat. '7, alt. '2. 
Hah. — Sandy mud, 6 — 10 fm. Panama, Cuming. — Panama, rare, 

C. B. Adams. — Mazatlan : extremely rare, L'pool Col. 

Tablet 113 contains 1 perfect valve. 

52. Tellina steaminea, Desh. 
Proc. Zool. Soc. 1854, p. 363. 

One specimen was found, about two-thirds the size of the 
Cumingian tj-pe which measures long. '33, lat. .48, alt. "17. 
It is kno^^n from neighboui'iug species by the rounded very 
faint concentric strise, which are clearly displayed by the 
microscope near the iimbo of the adult shell. 
^(t5.— Gulf of California, Col. Ciuning. — Mazatlan, from Spon- 

dylus washing : Upool Col. 

Tablet 114 contain the specimen. — 115 contains a minute 
valve and fragment which i)robably belong to the same. 

53. Tellina ddnacilla, n. s. 

T. t.jnn. donaciformi, valde transversd, tenui, canpressA, albd, 
concentrice Virata ; liris acutis, subccquidistantihus, alternis, 
medio sape evanescentihus, antice rafiorihtt,s ; epidermide tenuis- 
simii, line et illuc liras radiatim decussante ; postice valde 
productd, suhrotundatd ; antice angnlatd, truncatd, bra'issimd : 
marginibus ventrali dorsali que fere parallelis ; cardine dcntibus 
duobus quarum nnus bifidits cardinalibus, laterali una postico 
brevi appropinquante, extante. 

Belated apparently to T. donaciformis, Desh. from Torres 
Straits ; from -which it is known at once by the strong projec- 
ting lateral tooth. The shape is so remarkably like a Donax, 
1 luit I have only varied the termination from the British T. dona- 
cina. The specimen is young, but well characterized except in 
the inner surface, ^hicli does not displaj- the muscidar impres- 
sions. Long. "08, lat. '14, alt. '05. 
Hah. — Mazatlan : off Spondylus Lamarckii, L'pool Col. 

Tablet 116 contains the only valve foxmd. 



MAZATLAN BIVALVES 35 

1 

54. Tellina punicea, Born. 

Test. Mies. Cces. Vinci, p. 33, pi. 2, f. 2.— Dorset Cat. p. 30, pi. 7, 
f. 5. — Linn. Trans, vol. 8, p. 50. — Brit. Mar. Conch, p. 60.—^ 
Brotvn Illustr. Conch. Gr. Br. p. 100. — G-mel. Syst. Nat. 
p. 2,2ZQ.-—Wood, Ind: Conch, p. 20, no. A^.~Dillw. Bescr. 
C?a^. p. 90. — Lam. ed. Desk. vol. 6, p. 196. — Schroeter Einl. 
t. 3. p. 22, no. 79.— Desh. Enc. Meth. vers. t. 3, p. 1011. no. 12.— 
Hani, in Sow. Thes. Canch. vol. 1. j). 239, pi. 58, f. 89, and 
pi. 60, f. 154.— J?. M. Cat. Moll. D'Orh. p. 61, no. 433.— 
Forbes ^Sanl. Br. Moll. vol. 1, p. 314. 
= Donax Martinicensis, Lam. teste Gray. 
= Tellina alternata, Sow. teste Gray. 
= ,, angiilosa, Gmel. teste Desh. 
= „ simidans, C. B. Ad. Pan. Shells, p. 284. 
? = striata, CJwynn. Conch, t. 10, tab. 170, f. 1654-5 ; teste 
Dillivyn Sf Desh. : non Forbes ^ Sanley, Br. Moll., nee 
TLanl. in Thes. 

The late respected and very accurate Prof. Adams made liis 
T. simulans out of a valve he found of this species on what was 
(to him) the wrong coast. Unfortunately for his theory, the 
very slight differences he relied ou (deeper furrows coutuiued 
over the flexure, interspaces less flattened, and lateral teeth 
nearly obsolete) are not constant in the Pacific waters : and if 
one shell is common to the two oceans, which he is obliged to 
allow in the case of Crepidula uuguiformis, why may not this 
be ? The sheU is known at once by its regidar Tellinides shai^e, 
solid texture, pink colour variously banded with white, and 
deeply channelled furrows, some of which generally coalesce 
on one side before they reach the flexure. The angle of the 
ligamental area is more or less developed : the i)assage of the 
sulcations over the fold varies not only in difierent specimens, 
but in the same shell, in the opposite valves, or from young to 
old. The closeness and flattening of the ribs, the colour and 
the size of the lateral teeth also vary considerably, thoxigh I 
have only had an opportimity of examining about 4/) specimens. 
Long. 1-15, lat.Vd, alt. -4,7. 

Hah.— [Coasts of Britain, Pidten-ey, Wood, &c] — "A West 
Indian Shell, introduced into our Faima through having 
been iigured in the Dorset Catalogue as identical with striata 
Chemu." Forbes (Sf Hanley. — Mediterranean, Lam. ed Desh. — 
Cuba, Sagra in B. M. Cat. p. 36.— Brazils, UOrh. in B. M. 
Cat. p. 61. — St. Domingo, Sir. R. Schomberg, in B. M. — 
Trinidad, Haul. — This, like many other West Indian shells. 



36 MAZATIAJT BIVAtVES 

has found its -way into British and Mediterranaen lists with- 
out sufficient authority. 

T. striata, Chemn. ( = angvdosa, Gmel., = laetaPidt.=Don. Mar- 
tiniceusis, Lam. = T. punicea, Turton, Dillw. &c.) hah. W. 
Indies Coasts of Guinea, and Ehode Island, U. S. ; Chemn. 

T. simulans, C. B. Ad. hab. Xipixapi in W. Columbia* sandy 
mud, lOfm. ; Cuming. — Panama (1 valve), C. B. Ad. — Mazat- 
lan : ver>^ rare ; L'pool Col ; rare, Havre Co/.— Guayaquil, 
Sinds. 

Tablet 117 contains 2 pairs and 1 valve, shewing variations. 

55. Tellina PCumingii, JSanl. 

Pi'oc. Zool. Soc. 1844, p. 59.— Sow. Thes. Conch, vol. i. p. 223, 

pi. 58, f. 72.— a B. Ad. Pan. Shells, p. 281, no. 463. 

Tablet 118 contains 2 fragments which seem to present the 
colours and markings of this species. 
Hah. — Guacomayo, in coral sand, Cuming. Panama, extremely 

rare, C. B. yi(?«;«,y.— Mazatlan : fragments in shell washings, 

extremely rare ; L'pool Col. 



5G. Tellixa Pebuknea, Hani. 

Pfoc. Zool. Soc. 1841, p. 61.— Hani, in Sow. Thes. Conch, vol. i. 
p. '211, pi. 57, f. 91. 

Tablet 119 contains a fragment with deep sulci and, stout 
ribs, which may belong to this species. 

JTfti.- Tumbez, (Peru.) in soft sandy nuid, 5 fm., Cuming.— 
PMazatlan: in Spondylus washings, L'pool Col. 



57. PTellina regtjlaeis, n. s. 

?T. t.jun. suhorhiculari, convexiuscula ; margine ventrali suh- 
recto, umhonihus promt n<!ntihns ; diaphand, alba ; tenuissime ef 
conferUm cotwentrice liratd ; liris acuti^, interstitiis aut Itevibus 
aut hue et illuc lineis radian tibus vix decussaiis ; Jlexurd nulla ; 
ligamento minimo ; cardine dentihm cardinalilus 3, paululum 
divergcntibus, lateralibus 2 distantihus, validis. 

An aberrant species, so regular in form that externally it 
would range better with Kellia. It wants the spoon-shaped 



MAZATLAN BIVALVES 37 

process of Ciimingia, but tlie ligament is scarcely apparent. 

Long. -06, lat. 'OT, alt. -04. 

J5a6.— Mazatlan : from Spondylus washings ; L'pool Col. 

Tablet 120 contains all tbat was foimd ; viz. 1 perfect valve 
with a portion of the other. 



58. Tellina lamellata, n. s. 

T. t. "Tellinw lirce" simili, sed magis cequilaterali, et carina 
nmboimm carente : ImnelUs amtissimis, irregulariter tlhtanti- 
bus ; umbonibus valde prominentibics. 

A beautiful little shell, verj^ flat, thin, white, transparent ; 
cardinal and lateral teeth moderately strong ; spaces between 
the lameUse smooth ; -outline oval, very regular except where 
the umbos project ; flexure wanting. It might have been the 
young of T. lira, but for the entire absence of the stout umbonal 
ridge of that species. Long. '\, lat. '13, alt. '03. 
Sab. — Mazatlan ; nestling on back of Chamse and Spondylus 

Lamarckii, extremely rare ; L'pool Col. 

Tablet 121 contains 1 pair and 2 opposite valves. 

59. TeLLINA ?? PUELLA, C. B. Ad. 

C. B. Ad. Pan Shells, p. 283, no. 468. 

Tablet 122 contains an open pair and a valve wliich may 
belong to this species. I think however that the valve is dis- 
tinct, and displays certain symptoms of Semele, of which I 
have not seen the very young shell, and am therefore ignorant 
of its variation in growth. An unfortunate cough made away 
with the opposite valve, which however had previously adhered 
by an external ligament. WTiether there be an internal liga- 
ment as well, repeated microscopic examination has as yet failed 
to determine. Long. "075, lat. '095, alt. '035. 

60. Tellina ?? delicatula, Des/t. 

Proe. Zool. Soc. 1854, p. 363. 

Tablet 123 contains a fragment which may possibly be the 
young of this exquisitely beautiful species. Mr. Cuming's 
unique specimen displays, in addition to the features recorded 
in Desh.'s description, a pretty general penciling of a dark 
Sept. 1855. e 



38 



MAZATLAN BIVALVES 



colour in irregiilar radiating lines, crossing the oblique strxse. 
It measures long'. "37, lal. '64, alt. '12. 

^«i— Mazatlan ; Col. Cuming.—?? Mazatlan ; in Spoudj'lus 

washiugs ; L'pool Col. 

61. Tellina beevirosteis, Des/i. 
Proc. Zool. Soc. 1854, p. 362. 

This little valve seems to suit the description above quoted: it 
diflers from T. gracillima in being veiy ina?quilateral, the lateral 
and cardinal teeth very strong, and the lamellfe very regular, 
not much raised and rather close. Long. '03, laf. 05, alt. '015. 
iTai.— Central America and California [?Grulf], Col. Cum- 
ing. — Mazatlan ; extremely rare, jun ; L'pool Col. 

Tablet 124 contains 1 valve, and a fragment of a larger 
specimen. Nothing else was fo\md. 

62. Tellina ? denticulata, Desh. 

Proc. Zool. Soc. 1854, p. 365. 

Shell like a little T. crassa, with exceedingly large and 
projecting lateral teeth ; muscular impressions strongly mark- 
ed. Pallial line indistinct. The outside of both valves is vrorn, 
and prevents the identification of the species. Loni/. '065, 
lal. -07, alt. -02. 

Hall. — Unknown, Col. Cuming. — ? Mazatlan ; from Spondylns 
washmgs ; L'i^ool Col. 

Tablet 125 contains the only specimen. 

63. Tellina , sp. indet. 

Tablet 126 contains an imperfect valve remarkable for its 
3 strong rather divergent cardinal teeth ; the lateral ones are 
not developed, but there appear spaces for their reception 
from the opposite valve. 

Ilab. — Mazatlan ; off Spondylus ; L'pool Col. 

64. Tellina , sp. indet. 

Tablet 127 contains a broken valve remarkable for its sub- 
diaphanous concentric hues on a smooth surface. A fragment 



MAZATLAN BIVALVES 39 

with tlie surface indented may be an older form of the same 

species. Shell suborbicular, lateral teeth distinct. 

Sab. — Mazatlan ; from Spondylus washings ; L'pool Col. 

65. Tellina Bubneti, Brod. Sf Sow. 

Zool. Journ. vol. iv, p. 362, t. 9, f. 2.— Hani. Descr. Cat. p. 72, 

t. 13, f. 51.— Hani, in Sow. Thes Conch, vol. i. p. 271. 
= Lucina cristata, Recluz, teste Jay. 

After examining more than 300 specimens of this most 
aberrant shell, I cannot quote any noteworthy variations. It 
seems as though the creature was quite satisfied with its beauty, 
without endeavouring to improve it. The valves however are 
occasionally a little more bent, and the striae and knobs a 
little more or less close. To the shape of a Myadora, it adds 
the hinge of a Tellina. It has an Atlantic analogue, T. lunulata, 
found fossil in the Pleistocene beds of S. Carolina. In this 
however, the left and not the right valve is flat. A species of 
similar form is found fossil in the palaeozoic rocks, agreeing 
more with the Atlantic shell. fWbodw.J T. Burneti owes 
its present wide distribution in collections to this importation 
from Mazatlan : even this spring a specimen was sold at a 
London sale for 15s. Long. 1 ' 23, lat. 1 ' 37, alt. ' 23. 
Sai.— Found in the Estuary of Mazatlan, among the shoals 
of large Pinnae which are left dry at low water, Lieut. Bel- 
cher. — Salango, W.Columbia, Hanley. — St. Elena, Cuming. — 
Gulf of California, Mus. Cum.— W. Columbia, Lieut. Freer 
in Bristol Museum. — Mazatlan ; not uncommon ; L'pool Col. 
Tablet 128 contains 3 specimens of different ages. 

Genus STEIGILLA, Turt. 

StrigiUa Turton, pars. TeUina, atict. A group of TeUinidsB 
conveniently separated for their Lucina-like shape and di- 
varicated sculpture. 

66. Stbigilla (Tellina) caenaeia, Linn. 

Tellina carnaria, Linn. Si/st. Nat. ed. 12, p. 111^.— Donov. Br. 
Shells, vol. ii. pi. 47. — Linn. Trans, vol. viii. p. 57. — Dorset. 
Cat. p. 31. pi. 5, f. 6.— Turf. Conch. Diet. p. 177-— Chemn. 
Conch. Cab. vol. vi. p. 130, pi, 13, f. 12Q.— Wood Ind. Test. 



40 MAZATLAN BIVALVES 

p. 22, no. 79.—I>illw. Desci-. Cat. vol. i. p. l(X).—Gtnel. p. 3240, 
no. 70— Schroet. Einl. t. 2, p. Qm.—Mont. Test. Br. p. 73.— 
Born. Mus. p. 37, t. 2, f. 14. — Desk, in Lam. An. .v. Vert. vi. 
2W.— Hani. Bee. Sh. vol. i. p. 72, pi. 4, f. 79.— mini, in So^f. 
Tkes. Conch, vol. i. p. 260, pi. 56, f. 37, iS.—Forhe.'^ S, Sanl. 
Br. Mol. vol. i. p. 313.- Midden dorf Mai Boss. Abtli. iii. 
p. 60, no. 3.—B. M. Cat. B'OrJ). Moll. p. 61, no. 536.— 
B. M. Cat. Sagra Moll. p. 36, no. 434. 

Cardium carneosum. Da Costa, Brit. Conch, p. 181. — List. 
Conch, t. 339, f. 176. 

Lucina carnaria, Lam. An. s. vert. t. vi. p. 227, no. 8. — Flem. 
Br. An. p. 442. — Brit. Mar. Conch, p. 75. — Pai/r. Cat. de la 
Corse, p. 41, no. 68. 

Strigilla carnaria, Turt. Dith. Br. p. 118, i)l. 7, f. 15. 

? = Strigilla miniata, Gotild's dilates. 

I have not been able to see Gonld's description ; but as Mr. 
NuttaU informs me that this shell is plentiful at 8ta. Barbara 
and as his specimens are even more like the W. Indian ones 
than the Mazatlan shells are, I presume that the S. miniata is a 
further development of the theory which produced T. simulans, 
C. B. Ad. It appears to be a very widely diffused species, 
being one of the very few found N. and S, of the Gridf of Cali- 
fornia, and spreading through the Atlantic ocean probably to 
the Mediterranean and Euxine. Valves have been thrown up 
on our own shores. — The Mazatlan specimens are generally 
much paler than the W. Indian, but some have as deep a tinge. 
The character of the markmgs is exactly alike, though they 
vary among themselves in the crowding of the stria?, &c. They 
are occasionally marked witli a yellowish tinge, and are gen- 
erally more or less stained with black, probably from the mud 
in which they lived. The slieU appears to differ from T. sin- 
cera, Hani., found by C. B. Ad. at Panama, (rare.) Hani, gives 
it as from N. W. Coast of America on the authority of Dr. Sin- 
clair ; biit Nuttall's Californian specimens are undoubtedly 
T. carnaria. Long. "9, lat. '98, alt. '42. 

Hah. — [Scarborough, Devon and Cornwall, Da Costa, &c.] — 
Amei-icau Ocean, Wood. — Jamaica and Barbadoes, Lister.— 
Curacoa, Grouovius. — W. Indies, W. Columbia, Hani.— 
Cuba, iSf/f/TO.- Brazils, Z)'0>'i.— Mediterranean, Lam.Eisso; 
non Phiiippi, nee Forbes ; dubitat Middcndorf.— Corsica, 
Pfl//;'a«(/m«.— Naples, P. P. C— Sudate, Black Sea, teste 



MAZATLAN BIVALVES 41 

Rathhe, SiemascKke. — Santa Barbara, abundant, Nuttall.— 

Mazatlan : not common ; L'pool Col, 

Tablet 129 contains 6 pairs and 2 valves, shewing variations. 
The smaller valve may be T. cicercula, Phil., in Zeitschr.fur 
Mai. Feb. 1846, p. 19. I cannot however separate it from 
S. carnaria, of which it appears the young. The description of 
T. cicercula exactly applies to this, which is the left valve. 
Menk e m. quoting the species among Melchers' Mazatlan Shells, 
Zeitschr.f. Mai. 1847, p. 188, no. 53, says that it is only the left 
valve which possesses the sculpture in question : so does the left 
valve of T. carnaria, and that alone. Menke loc. cit. describes a 
uew species, T. areolata, from the West Indies, intermediate 
between T. cicercula and T. carnaria, with a simdar smooth 
space on the left valve. — Philippi also describes from Mazatlan 
(loc. cit.) T. lenticula, T. dichotoma, and T. ervilia. In his 
Abbd. Conch, for Aug. 1846, p. 24, he also gives the ancient 
T. pisiformis. Linn, (along with Diplodonta semiaspera) as 
common to Mazatlan and the Caribbsean Sea. Mazatlan must 
be rich in Strigdlse, according to Phdippi ! 



67. PStkigilla lenticula, Phil. 

Tellina lenticula, Phil, m Zeitsch.f. Mai. 1846, p. 19. 

Tablet 130 contains a broken specimen which probably be- 
longs to this species, which, says Pbiliijpi, while agreeing in 
form and size with T. pisiformis, has the sculpture of Lucina 
digitaria. It may however belong to Lucina eburiiea, Rve. 
Conch. Icon. pi. 8, f. 49, found in sandy mud, 11 fm., St. Elena 
and Panama, Cuming. 

Hah. — Mazatlan, Philippi. — ?Do. fragments, oflf the back of 
Chama ; L'pool Col. 



68. , sp. ind. 

Tablet 131 contains a fragment of a thiu shell of moderate 
size, perhaps a Psammobia, (possibly an unknown Donax,) 
strongly angulated, with very fine, slightly rugose striae, 
coarser on the angular part. It is white, slightly bordered 
with orange. 

Hah. — Mazatlan ; confined in the mouth of Trivia sanguinoa ; 
L'pool Col. 



42 mazatlan bivalves 

Family DONACID^. 

Genits IPHIGENIA, Schum. 
S//II. Capsa, Lam. 1818, (non 1801.) Donacina, Fer. 

69. Iphigenia altiok, Soto. 

Capsa altior, Proc. Zool. Soc. 1832, p. 196, (teste C. B. Ad.)— 

MUn. Syyi. Test. Viv. p. ^25.— Hani. Descr. Cat. p. 86 — 

Sanl. in Supid. to Wood's Ind. Test. pi. 14, f. 34.— C. B. 

Ad. Pan. Shells., p. 276, no. 453. 

Shell verv' variable ia outline, sometimes nearly equilateral, 
sometimes much produced anteriorly, sometimes incurved at 
the posterior ventral margin. The outside has the usual 
olivaceous epidermis. The inside is more or less stained with 
violet. Bifidity of cardinal teeth more or less developed : 
lateral teeth almost evanescent in one valve, absent in the other. 

Smallest specimen measures long.l', lat.1'37, alt. '56. 

Longest ., „ „ 1-88, „ 2-54, „ I'll. 

Aberrant „ „ „ 1-72, „ 2-12, „ 1-03. 

JTab. — Gulf of Nicoyia, in coarse gravel, 12 fm. Cuming. — Var. 

Tumbez, thin mud. 5 fm. Cuming. — St. Elena, Jay. — Panama, 

extremely rare, C. B. Adams. — Mazatlan : very common ; 

L'liool Sf Havre Coll.— The xUlantic analogue is I. Brazili- 

ensis. A closely allied species is from the Gambia; Chief 

Justice Pankin, Bristol Mus. 

Tablet 132 contains 5 specimens in the normal state. — 133. 
•5 specimens more transverse. — 134, 5 specimens indented. — 
135, 2 specimens of abnormal groii\-th.— 136, 1 specimen with 
verj' thin epidermis. 

70. Iphigenia Pl^vigata, ?cvJus. 

This shell is regarded by Dr. Gray as an abnormal variety 
of I. altior. It has much more the shape of I. Braziliensia. 
The most deeply indented I. altior is far removed from it. 
Mr. Cuming has similiar specimens from the same coast, which 
he regards as an uudcscribed species. I have seen it with the 
name Capsa lanigata, but do not know on what authority. It 
is characterized by very overlapping imibos ; subcarinated, 
Bubtrxmcated posterior side ; deep posterior ventral sinus ; 



MAZATLAN BIVALVES 43 

anterior side much elongated. Long.\'b2, (ad sinum 1"37.) 

lat. 2-28, alt. '9, (ad sinum -78.) 

^ai.— Mazatlan ; extremely rare ; L'pool Col. 

Tablet 137 contains the only specimen I foxmd : Mr. White- 
head of Liverpool found another. 

Genxjs DONAX, Unn.* 

71. DoNAX CAEINATUS, Sanl. 

Proc. Zool. Soc, 1843, p. o.—Bve. Conch. Icon. pi. 2, sp. 11.— 

Wood's Swppl. pi. 14, f. 28. 

Shell with a blunt keel, and posterior area covered with 
slightly expressed stria? which are scarcely rugose here and 
there. Epidermis very thin, deciduous except round the mar- 
gin. Ventral margin almost always regularly excurved. The 
purple colour generally predominates in this, as the chesnut 
in D. culminatus. Form and markings very constant, except, 
as usual, in the proportion of length and breadth. Long. *93, 
Int. 1-62, alt. -63. 
JTaS.— San Bias, Gulf of California, Eeeve.— Tumaco, Hinds, 

B. M. — Mazatlan ; rare ; Vpool Col. 

Tablet 138 contains 2 specimens in the normal state, and one 
with two remarkable laminae in the interior of one valve, near 
the posterior adductor. 

72. Don AX culminatus, In. s. 

J), carinatus, var : Hani. ms. teste Cuming. 

D. t. "D. carinato" simili, sed carina multo acutiore, productd, 
■margine vent rail scepe prope carinam paulum incuroato ; niten- 
tiore ; striis radiantibus obsoletis et crenulatione interna conveni- 
ente erebrioribus ; area postica striis radiantibus creberrimis 
valdeextantibus, granosis, granis versus marginem riigosis ,• 
castaneo-purpureo. 

I had passed this shell over as the young of D. carinatus, till I 
obtained a number of large valves with other West Coast shells, 
which at once displayed the remarkable characters of the 
posterior area, the sharp ridge, and the very granular crowded 
striae. Having examined more than 6() specimens of D. carin- 

* The specific termination being given as feminine in P. Z. S., B. M. Cat. 
B'Orb. Moll., Rve. Conch. Ico)i., Jay's Cat. &.C., it is desirable to remember that 
Donax is masculine both in Latin and Greek : (c. Lex.) In quoting, the tennin- 
ationa are altered accordingly. 



44 MAZATLAN BIVALVES 

atus, without seeing the slightest approach to these characters, 
I am obliged for the present to consider them specific. Size 
of the Mazatlan specimen ; long. '55, lat.*%, alt. "33. Ordin- 
ary size, as in D. carinatus. 

Sab. — Mazatlan ; 1 young specimen ; L'pool Col.* 

Tablet 139 contains this specimen, and two valves, probably 
from the Central American coast. 

73. DONAX TEANSVEBSTJS, Sow. 

Tank. Cat. App. p. 4, no. 226.—JRve. Conch. Icon. pi. 6, sp. 36. 
Known from D. scalpellnm, G-rai/, (Gulf of California) by 
the peculiar iacurving of the anterior dorsal line ; and by the 
character of the posterior area, which has at the margin one 
large and two smaU flexures, while the surface is covered with 
radiating strife, very finelv and granvdarly serrated. Long. ' 56. 
lat. 1-34, alf. -3. 

Sab. — ^lazatlan ; extremely rare ; teste S. Tyler, Esq., who 
found a fresh valve concealed in a Chama from the L'pool 
Col. The other valve is nowhere to be found. 
Tablet 140 contains this valve, most kindly presented bv 

Mr. Tyler. 

74. DoNAX ASsiMiLis, Sanl. 

Proc. Zool. Soc. 1845, p. 17.— C. B. Ad. Pan. Shelh, p, 277. 

no. 454. — Rve. Conch. Icon. pi. 2, sp. 10. 

This species is used for food at Panama, where the natives 
scoop to its depth, and keeping to the same level find them in 
great abundance. (C. B. Ad.) Long. -92, lat. VM, alt. 51. 
Sab. — Panama, Mus. Cuming. — Do. very plentiful, a few inches 

deep in sand at 3-4ths tide level, C. B. Adams. — Mazatlan, 

Lieut. Green. — Mazatlan ; 1 valve only ; L'pool Col. 

Tablet 141 contains the solitary valve. 

75. DoNAX PUNCTATO-STEIATCS, Sanl. 

Proc. Zool. Soc, 1843, p. ^.—Rve. Conch. Icon. pi. 3, f. 16. 
F<jrr. = D. radiatus Val. in Sumb. Pec. vol. ii, 1833. 
? = D. flexuosus, Gould's plates. 

* An extremoly similar shell is f<iTen in the Bristol Musenm as Donax rugosas, 
Br. Cutting, W. Indies. 



MAZATLAN BITALVE3 45 

Altliongli there is little doubt that Yaleneiennes' species is 
the rayed variety of this shell, and therefore has prioritj-, yet 
as his description is not acciu-ate enouph for certainty, and 
as it only applies to a very small part of the species, Hanley's 
expressive name is retained. The punctatostriate character 
however is by no means peculiar to this shell. Some forms 
are exceedingly hard to tell from D. Conradi, Besh. ; including 
D. contusa, Eve. The followiug are believed to be the main 
characters of the shell. Surface smooth, shining, with very 
thin deciduous epidermis, rarely seen. iSl^ot grooved, but with 
rows of extremely fine dots indented as with a bookbinder's 
tool. Eows often intercalated near the anterior end. Mar- 
gin with strong squarish creuations inside : the same outside 
toward the posterior slope ; about the middle, grooves appear 
di\-icling each, answering to the intercalary rows : at the end 
a broad surface is channeled off, in which each crenation gives 
off a fang something like a ( ' ) to join the external rays. This 
intricate and very characteristic structvu-e will generally tell 
the species at once from the aberrant forms of D. Conradi. In 
the po.sterior slope, the punctate rows are very close ; in the 
lunular portion entirely absent. The ordinary colour is pale 
yellow or white, sometimes a rich orange yellov>- ; generally 
rayed with pm-ple about the lunule with occasional stains 
elsewhere ; often tinged with green about the posterior slope 
and umbos, occasionally rayed with brown ( = D. radiata. V(d.) 
with the rays often not corresponding on the two valves. 
Umbos white or pale yellow, sometimes rich transparent orange, 
sometimes with a penciling of purple, sometimes two purple 
spots. Shape normally trapezoid, with the umbos sub-central : 
but often with the posterior part shortened, and the anterior 
much elongated. The end is then tapering : but often it is 
short and veiy gibbous. Ventral margin almost always well 
developing the angidar swelling. Inside generally rich purple. 
Lateral teeth short but very- strong, the anterior truncated : 
in the oi>posite valve small. 

Largest specimen measures 7o»f/. I'lo, laf.l'G-i, alf.'d. 

Transverse „ „ ., '96, „ 1'46, „ oT. 

Stumpy „ „ „ -79, „ VOG, „ -48. 

Smallest „ „ „ "IS, „ '26, „ -11. 

Sab.— South America, Capt. Ld. Byron [?].— Mazatlan : in 

extreme profusion ; L'pool Col. 

Tablet 142 contains 15 specimens, normal sliape, rich orange 
yellow. — 14;3, 10 sp. same colour, transverse shape. — 114, 9 sp, 



46 MAZATLAJf BIVALVES 

same colour, lunular purple ray on one valve only. — 145, 9 sp. 
same colour, purple rays absent.— 146, 10 sp. and 2 valves, 
pale yellow: this is the most frequent state.— 147, 8 sp. 
white, normal shape.- 148, 8 sp. white, transverse.— 149, 12 
sp. white and pale yellow, with irregular pale violet concen- 
tric bands.— 150. 5 sp. orange yellow, similarly banded.— 
151, 5 sp. stained with purple and green. — 152, 15 sp. yellow, 
green at imabos and posterior slope.— 153, 15 sp. whitish, band- 
ed mth violet, green at posterior slope.— 154, 9 sp. plain yellow 
T\4th greenish slope.— 155, 9 sp. white Avith greenish slope.— 
156. 7 sp. orange yellow stained with purple.— 157, 2 sp. and 
1 jalve, do, highly coloured, form approaching D. Conradi.— 
158, 6 sp. with broad brown rays. — 159, 6 sp. with verj- faint 
rays. — 160, 5 sp. shewing distorted growth. 

Besides these were found a few scores of specimens which, 
when examining D. punctatostriatus I have generally turned 
over to D. Conradi ; when examining the latter, have been dis- 
posed to turn back again. They are here grouped according to 
the preponderance of characters.— Tablet 161 contains D. punc- 
tatostriatus approaching D. Conradi, 4 sp. whitish.— 162, 6 sp. 
yellow. — 163, 3 sp. rayed.— 164^ 2 sp. yellow, transverse. — 165, 
3 sp. reddish, transverse.- 166, 3 sp. whitish. uaiTow margin.— 
167, 3 sp. very gibbous.— In all 192 shells, the result of very 
frequent elimination from an examination of many thousand 
specimens ; no two probably being exactly alike. 

75 (b.) DoXAX ? PrXCTATOSTKIATUS, var. CJELATUS. 

D. ? punctatostriatuK, t. maxime ineequilaterali, margine ven- 
trali vix anyidato .- superjicie posticd dense Uratd, ItHs ex- 
presds radiantihus : interstitiis dense decussatis, lineolis valde 
impressis : scidpturd partem versus anteriorem, in lineas punc- 
tarum mutante, punctis anyulatis : 7n a rc/ine pier unique simplia, 
epidermide densd rugosa teclo. 

Xearly W specimens have occurred, agreeing in the above 
characters, while only 2 shewed the least disposition to depart 
towards the ordinary type. Shape extremely inanpiilateral, 
anterior end much prolonged. Sculpture deeply marked on 
the i)osterior and posterior ventral part ; with elevated ridges, 
and the turj-ows not simple rows of dots as iu D- punctato-stria- 
tus, but witli short lines impressed as with a file-cutter's tool. 
These gradually subside anteriorly into punctate striation, but 
even then the dots are augidatcd, not round. There is a large 



MAZATLAJI B1VAIVE3 47 

smooth lunvdar portion, not specially colom*ed. Tlie margin 
is generally simple, nearly as in D. Conradi : and •when it has 
the intercalary grooves proper to D. punctatostriatus, they are 
rarely carried up into intercalary rows of dots. The epider- 
mis is remarkably thick round the margin. Colour sometimes 
white, occasionally yellow, but generally stained -with rich 
reddish purple. Whether it be an aberrant variety of D. pimc- 
tatostriatus, or a distinct species, must be determined when 
more specimens have been examined, or the animals studied. 
The largest but not characteristic specimen measured long. "91, 
lat. 1-37, alt. -57. 

Sab. — Mazatlan ; very rare ; L'pool Col. 
Tablet 168 contains 3 specimens, white, yellow and purple. 



76. DONAX CONEADI, Desk. 

Proc. Zool. Sac. 1854, p. ^l.—Bve. Conch. Icon. pi. 5, sp. 29. 

+ D. contusus, Rve. Conch. Icon. pi. 4, sp. 24. 

+ D. CaKfornicus, Conr. teste De/th. ms. B. M. & Col. Cuming : 

nequaquam, teste Nuttall. 
+ D. culter, Hani. Proc. Zool. Soc. 1845, p. 14. — Bve. Conch, 

Icon. pi. 4. sp. 21. 

It is not without the most careful, laborious and often 
repeated examination of upwards of 1,000 specimens that I have 
felt compelled to depart from the views of the illustrious 
Deshayes and the very accurate Hanley, and group together 
the species above quoted. The D. Californicus, teste jSTuttall 
whose shells were the basis of Conrad's descrix^tious, is very 
different from the shells so named by Desh. in the Br. Mus. 
and Col. Cuming ; the former being a smooth, gibbous, sub- 
triangular shell, more like a young D. punctatostriatus, though 
(^uite distinct. The name Conradi is preferred to culter which 
has priority, as expressing the adult form, and as leaving 
contusus and culter for the use of those who believe in the 
species, without introducing confusion. The shells wrongly 
called D. Californicus are simply the white variety of the forms 
contusus and culter. 

This creature loves liberty both in form and colour. The 
shape is generally transverse, not unlike the large variety- of 
D. anatinus, slightly swollen ventrall}', with a flattening towards 
the posterior end. Sometimes it tapers off at the anterior part, 
which is then somewhat flattened : sometimes the whole shell 



48 ^ MAZATLAN BIVALVES 

is very p:ibbous : sometimes subtriaugular, and even taking the 
form of D. punctatostriatus. The lines of growth shew that the 
adult by no means thinks it necessary to preserve the form of 
early Ufe : it being very common to observe the posterior part 
much developed in the young, while it is narrowed off in matu- 
rity ; or the shell is sometimes sub-oval when young, and very 
transverse afterwards. In colour there are similiar variations ; 
the youjig sheU abounding more in purple, while the adults 
reserve that colour for the inside, and content themselves with 
a greenish gray. Or a shell of an ochre yellow when young 
will change afterwards to a purpUsh tinge. The prevailing 
colour is a greenish gray, tinged with purple. This is very 
bright in the young, very dull in the adult. The purple is 
often absent in the adult, sometimes in the young ; rarely 
predominant. Ochre yellow sometimes i^revails, in the young 
beautifully shaded into purple or white. The wliite variety is 
tolerably common, with gradations into the other colours ; and 
often with irregular rays from the umbo to the anterior margin, 
which is but rarely seen in D. punctatostriatus. The same colours 
intensified are seen in the j'oung shells, and noted by HaTil. in 
his description of D. cidter. In these the changes in form are 
extraordinary ; some being nearly triangular, while others take 
an extremely elongated form, with a posterior ventral siuua- 
tion (D. culter, var. a, Hani.) ; but the intermediate forms are 
so various that I have not been able to separate them. The 
middle stage of growth of the gibbous form is D. eontusus, Rve., 
a species described from a single specimen in the Cumingian 
Collection. The surface of the shell is pimctatostriate ; with 
the dots finer and the rows further apart than in the last species. 
Towards the ventral part they generally subside into plain 
stria?. On the anterior part, they are often crowded and 
irregular, having jagged edges or I'unning mto little lines which 
are sometimes confluent. A large lunular portion is smooth. 
The general aspect of the shell is rather glossy, especially in 
the young shells. The form eontusus often retains the margin 
marks one after another, giving tlie shell a tiled appearance. 
Having examined every specimen luider the glass, I am unable 
to note any constant characters in the markings co-ordinate 
with the changes of form and colour. The crenations are gene- 
rally simple, without the broad marginal band conspicuous in 
D. punctatostriatus, and not shewing the intricate markings at 
the anterior end. I have observed no specific differences in 
the interior : the teeth and impressions are as in D. punctato- 
striatus, makmg allowance for the greater or less elongation of 



MA2ATLAN BIVALVES 49 

the shell : colour generally deep purple, with more or less of 
white. Epidermis very thin, deciduous. Umbos purple with 
wliite spot, occasionally rich orange. 

A transverse specimen measures. Zowf/. '83, lat, 1"52, alt. *5. 
A subti'igonal one ,, ,, "92, „ 1'53, „ "52. , 

The smallest „ „ „ -06, „ "OS, „ -02. 

JTah.—CD. culter) Mazatlan and Acapulco, Col. Cuming. — Maz- 
atlan ; common (tlie adult state rare, perhaps from burrowing 
deeper in the sand) ; L'pool Col. 

Tablets 169—173 contain forms intermediate between this 
species and D. punctatoatriatus. — 169, 4 sp. rayed. — 170,*4 sp. 
purplish yellow. — 171, 5 sp. purplish white.— 172, 7 sp. yellow- 
ish. — 173, 10 sp. more transverse. 

In the following series (except in the subtrigonal forms) tlu- 
very young are D. culter, Hani., and the intermediate ones 
are generally D. coutusus. Eve. : the white ones of both forms 
are D. Californicus, Desk, not Co)ir. — Tablet 174 contains 10 s]). 
with purple tinge predominant. — 175. 9 jun. and 2 adidt, very 
transverse, margin sinuous, pui^plish gray. — 176, 9 sp. less 
transverse. — 177, regular form, 1 pair, 2 valves very young.— 
178, 11 sp. very oval and regidar.- 179, 12 sp. less transverse, 
more gibbous.— 180, 12 sp. very gibbous.— 181, 9 sp. subtrigonal. 

Yellowish var : 182. 9 sp. transverse. — 183, 7 sp. oval, gib- 
bous.— 184, 6 sp. subtrigonal. 

Greenish var : 185, 11 sp. transverse. — 186, 10 sp. gibbous. — 
187, 10 sp. subtrigonal. 

Greenish white : 188, 12 sp. vei-y transverse.— 189, 6 sp. sub- 
oval. — 190, 7 sp. subtrigonal. 

Purplish white : 191, 12 sp. transverse.— 192, 7 sp. subtri- 
gonal. 
I White var : 193, 12 sp. ver\^ tranverse, — 194, 12 sp. suboval 

(that marked* is curiously ina^quivalve with sinuous margin.) — 
195, 12 sp. subtrigonal. 

Rayed var : 196, 12 sp. very transverse. — 197, 18 sp. oval.— 
191^, 12 sp. subtrigonal. 

Tablet 199 contains 5 young shcUs (culter,) with the umbonal 
spot much developed. — ^200, 3 sp. (form contusiis) yellowish 
white. — 201, 3 sp. yellowish purple white. 

In aU 292 specimens, no two being exactly alike. 
Sept. 1855. / 



50 MAZATLAN BIVALVES 

77. DoKAX NAVicuLA, Hani. 

Pfoc. Zool. Soc. mia, p. 15.— C. B. Ad. Pan. Shells, p. 278. 

no. 456. — Rve. Conch. Icon. pi. 4, sp. 18. 

A charming little species, both for its extreme beauty, and 
the distinctness of its characters. Shell singidarly swollen, 
margin gibbous, scarcely shewing crenations beyond the edge 
at the anterior end : clothed with very glossy epidermis, be- 
neath which are obsolete striae. Ordinary colour greenish 
white, gradu.ally assuming darker shades, often beaked with 
orange, generally more or less rayed, and ending in dark 
orange chesnut. Inside from white to fawn, ending in deep 
purple. Often (not always) with two streaks of purple within 
and without, bounding the lunular and jjosterior areas. It 
varies in the greater or less elongation, and in the ventral mar- 
gin which is sometimes incurved. One monster was found, 
shewing more prominent striEe, lojig'iA, I at. '9, ali. '29. 

Ordinary size „ "3, „ "66. „ .23. 

Smallest „ 2, „ "43, „ "14. 

Hab. — Gulf of Kicojna, Cuming. — Panama, E. Jewitt, C. B. 

Adams. — Mazatlau ; not uncommon ; L'pool Col. 

Tablet 2()2 coutalus 5 specimens, most common variety, very 
pale. — 203, 3 darker, tipped with orange. — 204, 3 darker, 
slightly rayed. — 205, 4 normal state, rather dark, indistinctly 
rayed. — 2f)6, 3 sp. rays more evident, tipped with orange. — 207. 
3 sp. bi'ownish orange. — 208, 3 the same deeper. — 209, 3 rich 
dark brown. 210, the monster. — In all, 28 specimens. 

Family MACTEID^. 
Genus MACTEA, Lin. 

78, Mactea exoleta, Grai/. 

Mag. Nat. Hist. 1837, p. 372.— Eve. Conch. Icon. pi. 4, sp. Ifi. 
This exquisitely bcautifid species is recognized easily b> 
the angle at the ])osterior side, and by the great prolongation of 
the flattened anterior margin, which rises into a sharp keel 
dividing the lunular portion. It differs from M. alata, Speng. 
( = M. carinata, Lam. teste Eve. ?) in having no laminar keel 
on the posterior angle. The epidermis which is deciduous, 
but closely adherent when fresh, only shews striae of growth, 
and gradually fades away towards the umbos which are always 



MAZATLAK BIVALVES 51 

white. The shape is very constant, only occasionally varying 
in the shortening of the anterior portion. The posterior lateral 
teeth are extremely small, the anterior of moderate size. Pal- 
lial sinus rather small and narrow. — I have seen this shell 
labeled as from the W. Indies, but without authority. It has 
probably been mistaken for Lutraria carinata, teste Gould, 
which he gives as the Caribbaean analogue of Lutraria ventri- 
cosa, ( = Mulinia ventricosa, C. B. Ad. Pan Shells, p. 293,) 
which is given from Panama and Mazatlan. ? Can this be the 
M. exoleta of Gray. V. Proc. Post. Soe. N. K. iv. 89 ; a work 
which, alas ! I have not been able to see. In the very young 
shell, the anterior margin is but little produced, and the pos- 
terior tooth is moderately large. 

Youngest specimen measures long. '16, lat. "21, alt. '1. 

The most ventricose „ „ 2-8, „ 3-73, „ 1*86. 

The largest „ „ 3-84, „ 5*33, „ 2-5. 

Hah. — Cape Horn [?] and West Columbia, Eeeve. — Guayaquil, 
Hinds. — Mazatlan ; not uncommon, L'pool Col. 
Tablet 211 contains 1 very young valve. — 212, 3 specimens ; 
one yoamg, of exquisite beauty ; one with the epidermis re- 
moved, shewing the interior (presented by J, Hibbert, Esq.) ; 
the other very large. 



79. Mactea (Spisula) feagilis, Chemn. 

Conch Cab. vol. vi. p. 236, pi. 24, f. 235.— _B. M. Cat. jyOrh. 

Moll. p. 56, no. 489.-5. M. Cat. Sagra Moll. p. 35, no. 418. 
= Mactra ovalina, Lam. An. s. Vert. ed. Desh. vi. 104, no. 21, 

(teste Gray.) 
= ]V[actra BrazUiana, Lam. An. s. Vert. ed. Desh. vi. 106, 

no. 27, (teste Desh.) 
= Mactra oblonga. Say, (teste Mve.) 

Mr. Cuming having compared this shell critically with both 
larger and smaller specimens in his collection, writes that it 
certainly belongs to M. fragihs, Chemn. (according to Desh.) 
The texture and epidermis are very different from M. velata, 
Phil, of which, for geographical reasons, I had thought it 
might be the young. It is remarkable for its double posterior 
ridge, great flatness, and large gape on each side. Long. 1*36, 
lat. 1-93, alt. '64. 

Mab. — W. Indies, Honduras and St. John's, Mus. Cuming. — 
Cuba, Sagra. — Kio Janeiro, Lalande, jun. (teste Lam.) — 



52 



MAZATLAN BIVALVES 



Brazils, Rio de Janeiro, Patagonia; "Baie Blanche, Voi/. 
no. 130," UOrhiyny. — Mazatlan ; one specimen was sent, 
quite fresh, papered up along with the Semeles ; L'pool Col. 
Tablet 213 contains the specimen. 

80. Mactea (Mulinia) angclata, Gray, ms. 
Rve. Conch. Icon. pi. ix. sp. 34. 

This species is known at once from the young of M. exolcta 
by its stout, subtrigoual growth, the shortness of the anterior 
portion and the rather distant umbos. The epidermis is extreme- 
ly thin, gradually passing off towards the anterior portion, as in 
M. exoleta; but diifers in being loose, lying in irregular concen- 
tric folds, fringed at the posterior angle. The hinge teeth are 
large and prominent ; lateral ones very finely shagreened. 
The muscidar impressions are singularly close to the margin 
of the shell; pallial sinus small, oval. ?Can this be the M. 
donaciformis of C. B. Ad. (Pan. Shells p. 293,) as the true 
M. donaciformis is given by Rve. as from N. Zealand.* This 
shell seems also to have relations with M. goniata. Gray, ms. 
(Proc. Zool. Soc. 1854, p. 70,) and with M. carinulata, Desk. 
(Proc. Zool. Soc. 1854, p. 67 : Eve. Conch. Icon. pi. 10, sp. 38), 
both from the gulf of California. Lone/. 2-25. lat. 3' 05, alt. 1-78. 
IIab.—Gul( of California, Eeeve.— S. W. Mexico, P. P. C— 

Mazatlan ; a ver\- few specimens were found with M. exoleta : 

IJpool Ciil. 

Tablet 214 contains two specimens ; one young with the 
epidermis perfect ; the other adult. 

Gems GNATHODON, Gray. 

Gnathodon. Gray, Am. Joiirn. of Scieme ? 1830.— Eangia, 
De.rmoul. Ac. Soc. Lin. de Bord. 1831.— Clathrodou, Conr. 
Sillim. Amer. Journ. 1833. 

81. Gnathodon (Eangia) teigona, Petit. 

G. t. solidd, suhtrigonali, albd, epidermide flavescente, pos- 
teriiis ritgosd, induta ; plus minicsve incequilaterali, jyarte pos- 
teriori awinlo ah umhonibus decurrente indistincte separata; 
umhonihuji suhcentralihus, distantihus, non spiraliter recurvis ; 

* Reeve however, under M. carinulata, sp. 33, speaks of M. donacifcrrmis as 
from the Gulf of California. ? Is it authenticated from both localities. 



MAZATLAN BIVALVES 



53 



Uneis mbohsoletis utrlnque ad marginem dorsalem decurrentibus, 
aream rhomhoideam ut in Area descrihentihus ; anterius Uneis 
lunulam magnam demonstrantibus : intus dentibus lat er - 
a lib us subfsqualibus , temdssime rugosis, non striatis ; 
sinu pallli minimo. 

The sliell differs from the typical species in its regular form, 
and consequent size of the anterior tooth, which in G. cuneatus 
is very short and bent up. If this be regarded as of generic 
importance, the name Eangia may be retained for this species. 
It has somewhat the external aspect of Mactra subtruncata, 
but the rounded character of the hinge teeth shews its affinities 
to be with Gnathodon. It has the aspect of a brackish water 
shell, and the paUial sinus is extremely small. The lines of 
growth outside are often beaded, which is the more rem.arkable 
as the margin is sharp, not crenulated. It varies, like other 
bivalves, in being more or less swollen ventrally, and less or 
more produced posteriorly. This constantly variable character 
among bivalves can hardly be the result of sex, as in the 
myriads of shells of Veneridge &c. which I have examined, 
instead of ranging imder two heads, there is every conceivable 
gradation of form. Indeed one of our most accurate Britislt 
malacologists denies the separation of sex in the LameUibran- 
chiata altogether: v. Clark, Moll. Test. Mar. Brit. p. 191. 
Long. -82, Za;!. 1-08, alt. -55. 

JIab. — Mazatlan ; rare ; L'pool Col. 

Tablet 215 contains 4 specimens, the largest and the smallest, 
and two intermediate ones shewing opposite forms of growth. 



Family VENEEIDyE. 

The genera in this famdy are so slightly defined that shell;^ 
classed in different sub-families by one naturalist will belong 
to the same genus of another. The most accurate divisions 
are those proposed by Dr. Gray, which will be found in Des/t . 
B. M. Cat. Veneridce, 1853. Many tiny shells were found 
among the shell washings, which there has been great difficulty 
in affiliating, from not having intermediate specimens, and 
from the change of form and hinge characters betweeii the 
fry and the adidt. It is j)robable therefore that there are many 
errors in the young of the following species. 



54 MAZATLAN BIVALVES 

Genus PClementia, G^ray. 
B. M. Cat. Ven. p. 197. 

82. ? Clementia geacillima, n. s. 

? C. t. suhtrigond, tenuissimd, alba, diaphand, concentrice 
liratd, liris rotundis, approximatis ; postice prolongatd. Intus 
dent. 3-4 diver gentihus, minutis : ligamento vlx monstrante. 

This shell comes nearer to Clementia than to any other 
genus I know ; nor is there any reason why it should not be 
found on the American shores of the Pacific. Some may rank 
it with Tellina. The teeth are more equally divergent than in 
the typical species. Long. '09, lat. '13, alt. "5. 
Hab. — Mazatlan ; from backs of Chamse and Spondylus La- 

marckii ; extremely rare ; JJpool Col. 

Tablet 216 contains 1 perfect and 2 broken valves. 

Genus TEIGONA, Megerle. 

Trigona, Megerle. teste Desk. B. 31. Cat. Ven. p. io—Millil- 

fcldt, teste Woodxc. Man. Moll. pt. 2, p. 305. 
= Trigonella, Conr. Hinds. 
= Cytherea (pars) Lam. 

Known from Cytherea and Dione by the trigonal shape ; 
numerous irregular cardinal and long lateral teeth ; and by 
the velvety pcriostraca outside the epidermis, of a dull white 
colour, which, being mistaken for dirt, is generally verj' care- 
fully cleaned off by collectors. Under the microscope, this 
appears like an irregular mass of needle-like crystals. 

83. Teigona badiata, Sow. 

Cytherea radiata. Proc. Zool. Soc. 1835, p. 23. — Hani. Descr. 

Cat. p. \OQ.—Sow. Thcs. Conch, p. 019, pi. 128, f. 28—31.— 

C. B. Ad. Pan. Shells, p. 273, no. 446. 
Trigona radiata, Desh. B. M. Cat. Ven. p. 51, no. 19. 
Venus Solangcnsis, B. M. Cat D'Orh. Moll. p. 68, no. 607. 
Trigona Byronensis, Gray, Anal. t. 8. p. 301, 1838. 
= Cytherea corbicula, Menke (non. Lam.) in Zeit.f. Mai. 1847, 

p. 189, p. 54 : also Soio. Thes. Conch, p. 614, no. 7 (pars), 

pi. 128, f. 39 (f. 37, 38 excl.) 



MAZATLAN BIVALVES 55 

? + (var.) Cytlierea semifulva, Menhe in Zeit. f. Mai. 1847, 

p. 190, no. 56. 
? = (var.) Cytherea gracilior, Sow. Thes. Conch, p. 615, pi. 128, 

f. 32.— (Trigona; g.) Desk. B. M. Cat. Ven. p. 53, no. 26. 
? 4 (var.) Cytherea Hindsii, Hani, in Wood Suppl. pi. 15, f. 39 : 
Proc. Zool. Soo. 1844, p. IIO.— Soto. Thes. Conch, p. 614, 
pi. 128, f. 27.— (Trigona H.) Desh. JB. M. Cat. Ven. p. 53, 
no. 25. 
.P? + (var.) Cytlierea intermedia. Sow. TJies. Conch, p. 615, no. 12, 
pi. 128. f. 35.— (Trigona i.) Desk. B. M. Cat. Ven. p. 49, no. 13. 
( Compare the Atlantic species T. mactroides, Born, Chemn. 
Dillw. [non Lam. nee Soio.'] Desh. B. M. Cat. Ven. p. 51, 
no. 20 : B.M. Cat. Sagra Cub. p. 40, no. 476 : = C. corbicula. 
Lam. Hani. Phil. Soiv. [pars,] Gfrat/, Menhe IZeit.f. M. 
1849, p. 40, non supra loc. cit.] Also T. Dillwyni, Desh. 
B.M. Cat. Ven. p. 49, no. 14 : = C. mactroides, Sow. Thes. 
Conch, p. 615, pi. 128, f. 36 [non ia>».]— The W. African 
analogue is T. tripla Lin. .- Desh. B. M. Cat. Ven. p. 52, 
no. 23 -.—Menke in Z.f. M. 1849, p. 40.— The Chinese ana- 
logue is T. ventricosa, G-ray, B. M. Cat. Ven. p. 53, no. 24.) 
This shell is never so tumid at the umbos [straight] as in the 
African or [twisted] in the East Indian species : to the West 
Indian T. mactroides however some forms bear so close an 
analogy that Menke (and in part Sow.) may well be pardoned 
for not discriminating them. Menke remarks that "its forms 
are as various as its fatherland — one should rather say mother- 
sea." At Mazatlan however its forms and colours vary ex- 
tremely in the very same mother-sea. It is generally pretty 
equally swollen, but sometimes much flattened towards the 
ventral part. Occasionally the whole shell is much compressed, 
in which state it may possibly be T. intermedia, Sow. The 
ventral line is sometimes well rounded, sometimes nearly 
straight. Sometimes the posterior part is much produced, 
occasionally however the anterior. It would be hard to give a 
specific description that would include all the varieties and yet 
exclude the W. Indian specimens : the general habit however 
is so far distinct that I have not felt at liberty to follow Menke 
in uniting them.* There is often, not always, an anterior gape, 

• I have unfortunately distributed several specimens of the white var. of the 
form T. Hindsii, as another species ; but having then examined only about 100 
specimens, I thouaht the velvety epidermis was peculiar to that form and colour. 
I have since found it however (though it is generally cleaned off) on the typical 
T. radiata ; and after often repeated examinations of some 600 specimens, I am 
compelled to unite them. 



56 MAZATLAN BIVALVES 

occasionally rather large : the margin is generally thickened 
in that part, as in Donax. The gro-wth of the teeth is very 
irregular. The posterior tooth is rugosely crenated in adoles- 
cent shells, but in very young ones this is not the case, and in 
old specimens it is frequently obsolete : in this state it becomes 
the T. semifulva of Menke. If I have rightly afiihated the 
young specimens, ('03 across) the creature begins as a sub- 
orbicular body, with very swollen and pointed umbos, white 
with a purplish tinge, the anterior part swollen. There are 
then only 2 teeth ; an enormous anterior lateral, and a small 
posterior, nearly at right angles. Gradually these lessen in 
comparative size, while the cardinal teeth are formed one bj- 
one, and the creature assumes a trigonal and afterwards a 
transverse form. The youngest which is undoubtedly T. radi- 
ata, (about '22 across,) has not yet attained its full compliment 
of teeth, and does not display crenations. — In colour, the sheU 
is generally more or less brown ; either in a diffused hue, or in 
in rays of endless variety, sharp or mottled ; straight or zigzag ; 
with the umbos almost always tinged with purple at the tip, 
with or without a white patch, bifurcate or irregvdar. Earely 
however most of the forms take a uniform didl white, without 
purple tips. The shell generally forms iiTegular ridges of 
growth, as in Dione aurantia. 

A transverse specimen measures long.\'T2, Za#. 2 '23, aZ^. 1"14. 

A thick „ „ „ 1-88, „ 2-3, „ 1-34. 

A rounded „ „ ,, 1'57, ,, 1'82, ,, 1. 

A produced „ „ „ I'Tl, „ 1-97, „ I'll. 

^«i.— Salango and Xipixapi ; in sandy mnd, 9 fm ; Cuming.— 

Ecuador; Xipkapi, Z)'0;-i/(/«y.— Panama, extremely rare ; 

C. B. Adams. — Mazatlan ; very common ; L'pool Sf Havre 

Coll.—(T. Hindsii) Guayaquil Bay, Mus. Cuming.— (T. gra- 

cilior) loc incog. — (T. semifusca) ]\Eazatlan, Melchers. — (T. 

intermedia) California, Mus. Cuming. 

Tablets 217 — 235 contain specimens arranged to shew varia- 
tions in form. — 217, 3 sp. very transverse. — 218, 3 sp. rather 
less. — 219, 3 sp. somewhat rounded, tumid. — 220, 4 sp. very 
regidarly rounded.— 221. 1 sp. ventral line flattened.— 222, 
1 sp. posterior part produced. — 223, 1 sp. anterior part pro- 
duced.— 221, 3 sp. gibbous.— 225, 3 sp. subtriangular.— 226, 
4 sp. and a valve, subtriangular, produced anteriorly. — 227, 
1 sp. extreme form, flat, gaping,— 228, 1 sp. with crenations 
outside, as sometimes in Gnathodon trigona. — 229, 1 sp. dis- 
torted growth, gaping extremely.— 230, 1 sp. mantle cut. 



MAZATTAN BIA'ALTES 57 

WTiite or very fainthj streaTced variety. — Tablet 231 contains 
4 sp., regular form, various ages. — 232, 1 sp. flattened, round- 
ed. — 233, 1 sp. produced ventrally. — 234, 1 sp. transverse, 
gaping posteriorly. — 235, 1 sp. very transverse. 

Tablets 236 — 241 are arranged to shew tranMtions of colour ; 
but many of tbe specimens are also remarkable for form. — 
236, 3 sp. wkite, with very faint brown markings. — 237, 3 sp. 
brown rays narrow, interrupted. — 238, 2 sp. very narrow and 
numerous rays. — 239, 3 sp. with broad, sharp rays. — 240, 3 sp. 
brown predominant. — 241, 3 sp. diffused brown. 

Tablet 242 contains 6 pairs, extremelj^ young, which pro- 
bably' belong to this species. 

Tablet 243 contains 2 j^oung valves, which may belong to 
the transverse white varietj'. 

84. Teigona humilis, n. s. 

T. t. juniore ovali, umhonibus aijpressis ; ? adult a parvd, 
suhtrigond, margine ventrali excurva, laid; umhonibus non 
incurvis, parum prominentibus ; lavi, vel striis ino'ementi exili- 
bus: fused, intus onaculo p^trpureo dente postico ; 
dent, lat., antico brevi, solido, postico longo, exili ; card. 2-3 
parvis ; lined p)cillii a margine remotd, sinu parvd, subascen- 
deyite ; Ugamento celato, brevi; epidermide tenui. 

This shell might be taken for the young of Dione chiona^a, 
but for the entire absence of spirally recurved vimbos ; it differs 
also from the shells supposed to be the young of T. radiata in 
the flatness of the umbos and the comparatively s;nTaLl size of 
the teeth. Not being able to affiliate it with any satisfaction, I 
have been compelled to describe it provisionally. In the 
youngest stage only the lateral teeth are prominent, and the 
shape is almost oval ; then the anterior tooth turns round and 
makes a cardmal, and afterwards the other cardinal teeth ap- 
pear. There seems always a stain of pui-ple inside the ligament. 
When adult, it becomes subtrigonal, with the dorsal margins 
rather straight. Neither lunule nor area are defined. 
Theyoungest specimen measures /o«r/. "02, /a^. '035, alt. 'Olo. 
The largest „" "ll, „ -16, „ "07. 

Hah — Mazatlan ; rather uncommon, in Spondylus and Chama 

washings ; L'pool Col. 

Tablet 244 contains 2 pairs united, and 4 pairs of valves of 
different ages. 



58 MAZATLAN BIVALVES 

85. Teigona abgentina, Scnc 

Cytherea argentina, Proc. Zool. Soc. 1835, p. 46. — Hani. Descr. 
Cat. p. IQ^:— Wood's Suppl. pi. 15, f. lo— Phil. Ahbild. 
Conch. Cyth. pi. 3, f. 5.—Soio. TJies. Conch, p. 622, pi 129, 
f. Q2.—?Menl-e Zeitsch.f. Mai. 1847, p. 189, no. 55. 

Trigona argentina, Desh. JB. M. Cat. Ven. p. 50. no. 16. 

Tlus shell may be known at once from those varieties of 
T. radiata which most approach it by the very remarkable and 
constant shape ; being most regularly excurved along the ven- 
tral inargin. incurved on the anterior and straight on the pos- 
terior dorsal lines. Colour dull white, with light olive green 
epidermis ; often with two rays of violet within. The anterior 
cardinal tooth is much larger than in T. radiata, and the pos- 
terior tooth does not display rugose sidcations. The anterior 
adductor scar is less deeply impressed and more evenly bounded. 
Long. 2-12, lat.-Z-Q, alt'.Vb-I. 
Hah. — Gulf of Nicoyia, in sand banks at low water, Cuming. — 

? Guaymas, Lieut. Green, (Gould ms.*). — Mazatlan ; 3Iel- 

chers. — Do. very rare ; L'pool Sf Havre Coll. 

Tablet 245 contains 3 minute valves, the smallest "04 across, 
which may belong to this species. 

Tablet 246 contains 2 specimens. The smallest displays the 
violet rays, and an abnormal lamina within. 

86. TkiGONA ?.►* CKASSATELL0IDE8, Conr. 

Ann. Nat. Hist. Soc. Philad. t. 7, p. 253, pi. 19, f. 17.— Hinds, 
Vol/. Sulph. Moll p. 65, pi. 21, f. I.— Desh. B. M. Cat. Ven. 

p. 46, no. 1. 
C\i:herea crassatelloides, Hani. Descr. Cat. p. J06 : — Wood 

' Suppl. pi. 15, f. 32.— -Sow. Thcs. Conch, p. 612, pi. 127, f. 1—3. 

Tablet 247 contains 2 small valves, (the smallest 'Ol across) 
wluch have the shape aud thickness of this species. Their 
identity however is doubtful, T. crassatelloides belonging 
strictly to the Californian faima, where it attains a diameter 
of 5 inches. (Woodw. Nutt.) 

* Dr. Gould writes "Veuus straminea, Conr. = argentina ?" Tapes straminea, 
Conr. is the Californian representative of T. bistrionica or T. grata. It is pro- 
bable therefore that our shell is meant, as Tr. argentina is a well known and 
constant form. It is possible however that it may not be known to Gould, and 
that the first shell is meant : also that Menke's Cytherea argentina is one form 
of T. radiata. 



MAZATLAN BIVALVES 59 

Hab. — Sta. Barbara ; Nidtall, Col. Jeivett. — San Diego ; Lieut. 
G-reen. — Mazatlan ; Lieut. Green. (Grould ms.) — ?? do ; from 
shell washings ; L'pool Col. 

87. Teigona planulata, Brocl. Sf Sow. 

Cytherea planulata, Zool. Journ. vol. v. p. 48.— Sow. Gen. f. 2. — 

Bve. Conch. Si/st. vol. i. p. 94, pi. 69, f. 2.— Hani. Descr. Cat. 

p. ia5.—Zool. Beech. Voy. p. LSI, pi. 43, f, Q.—Sow. Thes. 

Conch, p. 618, no. 20, pi. 127, f. 13. 

Venus planulata, B. M. Cat. B'Orh. Moll. p. 66, no, 587. 

Trigona planulata, G-)'aij Cat. Cyth. Anal. vol. viii. p. 304. — 

Desh. B. M. Cat. Ven. p. 48, no. 8. 
+ Var. sufFusa, Soto. Proc. Zool. Soc. 1835, p. 46. 
+ Cytherea undulata, Soio. Thes. Conch, p. 618, no. 21, pi. 127, 

f. \%— (Trigona u.) Besh. B. M. Cat. Ven, p. 48. no. 9. 
=Donax Lessoni, Desh, Enc. Meth. vers. t. 2. p. 99. 
= (teste Desh.) Cytherea mactroides, Lam. {nonBornnec Sow.) 
An. s. Vert. vol. vi. p. 307, no. 27. — Deless. Bee. de Coq. pi. 8, 
f. 2.— Hani. Descr. Cat. p. 99 : Wood Siippl. pi. 13, f. 17. 
The very illustrious Deshayes in his later works seems much 
more disposed to the multiplication of species than he was in 
his earHer edition of Lamarck. He follows Sow.jun. in divid- 
ing the C. planulata of Brod. Sf Soiv. The C. undulata is 
discriminated by its more equal form, greater sohdity, absence 
of posterior gape, distinctness of lunule and style of painting, 
I have not found any one of these characters constant. The 
species varies almost as much as its more swollen congener, 
T. radiata. In form there is a gradual passage between the 
two. The undulata; are if anything thinner than the planulata;. 
The breaking up of the coloured rays proceeds by insensible 
gradations, and the colouring of the interior varies greatly. 
The gaping is either posterior, or anterior, or both, or some- 
what ventral, or none, just as it hapijens. The beaks are scarcely 
ever tipped with purple. The painting of the two valves does 
not always correspond. The teeth are very small and angular ; 
anterior lateral much prolonged. The W. African analogue is 
T. bicolor, Hani. 
Typical form measures long. 2', lat.2'Z, alt.l'. 
Var. undulata „ „ 1-78, „ 2-2, „ -88. 

H<ih. — Panama, Cuming. — Chili ; Coquimbo ; D'Orhigny. — 
Found abundantly near Mazatlan ; Lieut. Belcher. — Maz- 
atlan ; not common ; L'pool Col. — Var. suffusa ; Salango, 
sandy mud, 9 fm. Cuming, — Var. undulata, do. Cuming. 



00 MAZATLAJf BIVALVES 

Tablet 248 contains 3 young specimens, dull asli colour, 
slightly rayed, one with slight gape.— 249, 1 sp. adolescent, 
closed, slightly rayed on one valve, the other mostly dull 
brown.— 250, i sp. larger, closed, margin waved.— 251, 1 fine 
adult sp. gaping posteriorly and ventrally.— 252, 2 sp. very 
slightly gaping, rays clouded.— 253, 1 do., form imdidata, gap- 
ing nearly aU round.— 254, 2 do. form and colom-ing intermedi- 
ate ; one gapes posteriorly, the other ventrally. — 255, 2 pairs 
and 2 valves, form nndidata, large posterior gape.— 256, 3 do. 
valves closed ; of which one is nearly white inside, another of 
a rich diiFused violet. Similar differences of colour may be 
observed in the other specimens. 

Genus DOSINIA, Scopoli. 

Dosinia, Scop. Intr. ad Hist. Nat. p. 399, {1111). — Desk. 

B. M. Cat. Yen. p. 5. 
Artemis, PoU, Test. utr. Sic. p. 98, t. 1. (1791). 

88. Dosinia Ppondekosa, Gra?/. 

Artemis pouderosa, Gra?/ Anal. (1838), vol. viii. p. S09.— Eve. 
Conch. Icon. pi. 1. f. 'i.Sanl Baser. Cat. p. 109, pi. 19, 
f. 38.— <Soty. Thes. Conch, p. 656, no. 3, pi. 140, f, 2. 
Dosinia ponderosa. Desk. B. M. Cat. Yen. p. 7, no. 5. 
Cytherea gigantea, Phil. Ahhild. Conch. Cyth. p. 33, pi. 7, f. 1. 

p. 9, no. 7. 
Venus cycloides, B. M. Cat. D'Orb. Moll. p. 67, no. 596. 

A smgle specimen in beautiful condition, after being referred 

to D. concentrica (Gulf of Mexico), and D. distans (unknown ; 

probably Puerto Portrero). was at last doubtfully affiliated to 

this species by Mr. Cuming. A larger specimen procured 

since from another dealer, and proliably from the same collei-- 

tion, confirms the judgment. It is remarkable for the very 

orbicular form, slightly angidated beyond the ligament ; deeply 

cut kuiule ; and very regidar and distant snlci, not obsolete in 

the midcUe, of which, measuring from 1 to 1-5 in. from the 

umbo, there are only 8. The epidermis is extremely glossy, .^t 

a very light straw colour, iow^. 1'61, /a^. 1"74, alt.'Ti. 

iTfl?;.— Gulf of California, in sandy mud at low water, Sowerby. 

— Pei-u; Payta, Z>'Ori/i/«//.— Mazatlan ; extremely rare ; 

L'pool Col. 

Tablet 267 contains the specimen. 



MAZATLAN BIVALVES 61 

89. DosiNiA Ann^, n. s. 

D. t. compress a, elong atiore, marginihus cequaliter 
arcuatis : sulcis concentricis subcUstantibus, k a ti d i mp res- 
sis, medio subobsoletis ; lunula oblongd, subim(pressd ; lacted, 
epidermide Jlavesceitte, medio tenuissimd ; dentibus liaud valde 
divergentibus : sinu pallii liaud magno, angulato, apice ad 
m arginem ventralem muse, adduct. ascendent e. 

This fine , and (for a Dosinia) well marked species is known 
from D. ponderosa by its greatly elongated form ; from D. 
Dunkeri by its larger size, flatter growth, smoother ribs (the 
difference being at once perceived by di-awing the naU along 
the two shells) which are obsolete in the middle ; and especially 
by the shape of the pallial sinus, which in D. Dunkeri almost 
always points t ) the middle, in this towards the ventral edge 
of the anterior adductor. Lpng.2'4A, lat.2"B5, alt. 1"12. 
JTab. — Mazatlan ; very rare ; L'pool Col. 

Tablet 258 contains a young and a full grown specimen. 

90. DOSINIA DUNKESI, Phil. 

Cytherea Dunkeri, Phil. Abbild. Conch. Cyth. p. 4. no. 5, 

*pl. 2, f. 9. (Oct. 18M.) 
Artemis Dunkeri, Rve. Conch. Ic. pi. 6, f. 34. — Ad. Sf Rve. Voy. 

Samarang, p. 78, pi. 21, f. \1.—Sow. Thes. Conch, p. 657, 

no. 7, pi. 140, f. 5.— C. B. Ad. Pan. Shells, p. 274, no. 448. 
Dosinia Dunkeri, Desh. B. 31. Cat. Ven. p. 8, no. 9. 
= Artemis simplex, Hani. Proc. Zool. Soc. Jan. 184'.5, p. 11 : 

Descr. Cat. Ap. pi. 19, f. 41.— Rve. Conch. Ic. pi. 10, f. 9.— 

Sow. Thes. Conch, p. 657, no. 8, pi. 140, f. 6.— (Dosinia s.) 

Desh. B. M. Cat. Ven. p. 9, no. 11. 
Cytherea Pacifica, (Mm. Berol.J Trosch. in Wiegni. Archiv. 

'p. 324, (non Dillw.) 

After very patient but altogether ineffectual attempts to 
separate D. simplex of the monographs from D. Dunkeri, in the 
many hundred specimens which have passed under review, I 
am imformed by Mr. Hanley himself that his species is the 
same as PhUippi's ; and as the name of the latter bears date a 
few months earlier, it is necessary to preserve it. The shell is 
known by its very rounded, inflated form, more or less produced 
ventrally ; the more produced form is the D. simplex of the 
monographs. It varies somewhat in the closeness of the stria", 
Sept. 1855. g 



62 MAZATLAN BIVALVES 

but witli tliese exceptions is tolerably constant in cliaracter. 
Colour wbite, with, thin light straw-coloured or yellowish epi- 
dermis. 

A typical specimen measures long. 1'7S, lat. 1'76, alt. l'04i. 
A produced ,, „ „ VT, „ I'GS, „ -92. 

Sab. — Pacific shores of Mexico, Philippi. — Panama, St. Elena, 
Mus. Cuming, (Hani.) — Panama, not common, C. B. Ad- 
ams. — Eastern Seas, A. Adams. — Mazatlan ; very common ; 
L'pool ^ Havre Coll. 

Tablet 259 contains 5 young si)ecimens, the smallest '81 
across. — 260, 5 do. adult. — 261, 5 do. jun. closer stria. — 262, 5 do. 
adult. — 263, 6 sp. distant striae. — 264, 5 sp. adolescent, produced 
foiTu. — 265, 4 do. adult. 

Gentjs CYCLINA, Besl. 

Cyclina, I>esl. TraiU EUm. (1849) i. pi. 14 bis, f. 20-22.— 

B. M. Cat. Veil. p. 29. 

As the animal of this genus is said by Gray to be like Dosuiia. 
while that of Lucinopsis (Forbes Sf Hani. Br. Moll. 1848, vol. i. 
p. 433) is very different, being closely allied to the Tellinida>. 
(Clark, Moll. Test. Mar. Brit. pp. 132 et seq.) both genera will 
have to be preserved ; and the location of diifcrent species 
must await our knowledge of their animals. 

91. Cyclina subquadrata, Sanl. 

Artemis subquatbata, Proc. Zool. Sac. 1845, p. 11 -.—Descr. Cat. 

App. pi. 15, f. m—Rve. Conch. Icon. pi. 3, f. Ib.—Soic. Thes. 

Conch, p. 661, pi. 141. f. 27. 
Luciuopis subquadrata. P. P. C. Cat. Prov. 
Cyclina subquadrata, Desh. B. M. Cat. Ten. p. 31, no. 4. 
= Arthemi8 saccata, Gould, Proc. Bost. Soc. Nat. Hist. J851, 

p. 91 -.—Mex. Sf Cal. Shells, p. 23, pi. 15, f. 2.— (Artemis s.) 

C. B. Ad. Pan. Shells, p. 275, no. 4/19.— Cyclina s.) Desh. 
B. M. Cat. Yen. p. 32, no. 9.* 

This shell agrees in form and muscular impressions with 
Lucinopsis, luit the teeth are those of Cyclina. The young shell 
is much more orbicular in form. I picked a valve from a col- 
lection of W. Indian shells which exactly resembles this species 
in aU respects except the anterior muscular impression, which 

• IT aviiifr just received the Itype specimen of A. saccata, thi'ough the great 
kinduess of Br. Gould, I can speaJi to its exact identity. 



MAZATLAN BIVALVES 63 

is gomewliat nearer to tlie hinge, with, the sinus less ascending. 

Epidermis extremely thin. iow^. 1 '51, lat.l'54i, alt. '8. 

Sab.— St. Elena, West Columbia [?] very rare, Mus. Cuming. 
(Haul.) — Panama, extremely rare ; C. B. Adams. — Mazat- 
lan ; Lieut. Green. — Mazatlan, extremely rare ; L'jpool Col. 
Tablet 266 contains the largest specimen. 



Genus DIOjSTE, Megerle. 

Dione, B. M. Cat. Ven. p. 54. == Cytherea (maxima pars). Lam. 
Known by the smooth posterior teeth, ovate transverse form, 
and large horizontal paUial sinus. 

92. Dione aurantia, Hani. 

Cytherea aurantia, Hani. Sp. of Shells, Append. : Wood Suppl. 

'pi. 15, f. 20.— Sow. Thes. Conch, p. 228, pi. 132, f. 97 bis. 
Chione aurantia, G-rai/, Analyst, viii. 305. 
Dione aurantia, Desh B. M. Cat. Yen. p. 56, no. 3. 
Cytherea aurantiaca, Soio. Gen. f. 3. — Eve. Conch. Si/st. pi. 69, 

f. 'd.— Jay's Cat. p. 35.— C. B. Ad. Pan. Shells, p. 272, no. 444. 

This magnificent and tyi^ical si^ecies ax^pears to belong to the 
N. W. tropical province. The shape in regularity more nearly 
coincides with D. chione than with D. chionsea. It is however 
larger and heavier ; less transverse, lunule less mai'ked, and 
shewing a tendencj^ to in'egular concentric ridges of growth. 
The trifurcate white mai'k at the umbos has shorter and broader 
rays. The colour is a liglit salmon with occasional concentric 
bands of darker, in the young shell generally wliite at the 
margin ; covered with a uniform, rather thin, adherent, dark 
orange epidermis. Inside white, with purple stain on the liga- 
mental portion. Anterior adductor deeply impressed : the 
rest nearly as in D. chione. I have not been able to trace 
Sow.'s "obscure biangulato, &c." copied by Desh. Long. S'62, 
lat. 4"28, alt. 2 '37. A specimen from S. W. Mexico is some- 
what larger. 

£rti.— Gulf of Nicoyia, Jay. — Taboga, very rare, C.B. Adams. — 
South America [? ; non D'Orb. nee Cum.] ; Acapvdco ; Desh- 
ayes.— S. W. Mexico, P. P. C— Mazatlan; Lieut. Green.— 
Do. not common ; L'pool Col.* 

•"Brazil;" Manchester Mus. , without authority; probably an error. 



64 MAZATLAN BIVALVES 

Tablet 267 contains 2 minute valves, the smallest '03, across, 
which, may belong to this species. 

Tablet 268 contains 2 yonng specimens. — 269, 2 sp. very 
large. — 270, a distorted sp. with one valve overlapping. — 271, 
another distorted sp. with a large anterior gape. 

93. DioNE chion.i;a, Menlce* 

Cytherea chionrea, Menke in Zeit.f. Mai. 1847, p. 190, no. 57. 

Cytherea squalida, Sow. Proc. Zool. Soc. 1835, p. 23. — Hani. 

' Descr. Cat. p. 101: Wood's Siippl. pi. 13, f. 4f).—Sow. Thes. 

Conch, p. 629, pi. 131, f. 87-89.— C. B. Ad. Pan. Shells, 

p. 273, no. 447. 
Chione squalida, Grai/ Cat. Cyth. Anal. 1838, viii. 306. 
Venus squalida, B. M. Cat. B'Orb. Moll. p. 68, no. 609. 
Dione squalida, Desh. B. M. Cat. Yen. p. 58, no. 6. 
+ Cytherea biradiata, Gray, Zool. Beech. Voy. 1839, p. 151, 

pi. 43, f. 5. — Slehold. in IViegm. Arch. 
+ Cytherea chione, pars, Soto. Thes. Conch, p. 629, no. 59. 
p = Cytherea elegans, Koch, in Phil. Abbild. Conch. Cyth. 1844. 

p.2(150)pl. 1, f. 4. 

For a full description of the main features of this shell, v. 
Cytherea chione, Forbes Sf Sanl. Br. Moll. i. 396—8, Avhich 
applies in most of the minute particulars, even in that which 
is said to separate it, the 3 short ray-Uke colourless markings 
of which the central is the shortest, and the others margin the 
commencement of the lunule and the ligamental area. It is 
necsssary however to state, for the benefit of those who think 

* The learned have hardly behaved well to this exquisitely ^beautiful species. It 
was first described from some Peruvian shells of a " very dull and dirty aspect,"' by 
Sow., under the name (very inappropriate to the species generally) of C. squalida. 
He confesses however that" one of the varieties is " rather agreeably ornamented 
with concentric purple bands." The Mazatlan shells were next described by 
Gray, iu the Zool. Beech. Voy., as C. biradiata, a name apphcable again only to 
a portion of the species. The East Indian shells were next named by Koch and 
described by Phil, in 1814 as C. elegans. Then Sow. jun. in 1S51 gives in quo- 



He also tells us (an error which C. B. Ad. very politely exposes) that the species 
was first named from Philippine specimens brought by Mr. Cuming ; and also that 
the name C. biradiata iu Beechey's voyage was given to the Phihppine shells. 
Not content with these errors, he also informs us that Mr. Cumings's Mazatlan 
specimens belong to the Europa>an C. chione.— Last of all Menke gives the name 
C. chionroa to the Mazatlau species ; and though he only describes from a single 
specimen, it fortunately happens that both name and description are sufDciently 
comprehensive. As the prior names only apply to portions of the species, the 
ordinary rules of priority are disregarded in order to retain an expressive name 
which includes the whole species. 



MAZATIAN BIVALVES 65 

that Cythereae may always be known by the umboual markings, 
that in this species they are extremely variable : the white 
rays take very different directions : or it is not rayed at aU : 
or the white is entirely absent. The colour varies from dark 
lustrous brown to light grey : sometimes uniform, often biradi- 
ate with dark brown, generally more or less spotted in the 
young shell ; oceasionally tinged concentrically -with red, ver\- 
rarely with purple or greenish, but never with the reddish 
chesnut which is very characteristic of D. chione. The inside 
also is often stained with violet, oceasionally with yellow. The 
principal difference from D. chione is the shape, which is more 
swoUen, almost subangulated in the posterior dorsal portion, 
the angular line generally ending in a produced posterior 
margin. These characters however are not constant. There 
is a spotted variety rather hard to distinguish from its W. In- 
dian analogue, D. maculata, not being less tumid (as Sow. 
states,) but rather more, and losing the posterior angulation. 
The paUial sinus in D. chione is generally defined by a some- 
what broader line, and is a little more pointed ; though I found 
the shape vary not a little in the many hundred specimens of 
D. chionsea which I have earefidly examined. 

The East Indian specimens (if Philippi's figures are correct) 
have the ligament rather shorter, the lunule longer, and the 
pallial sinus less angulated. In other respects they exactly 
agree, and are considered identical by the very accurate Desh. : 
not, of course, for geographical reasons, by C. B. Ad. If dis- 
tinct, they will take Koch's name of D. elegans. 

If I have rightly affiliated certain very small valves, the 
young sheU (of which the smallest measures only '02 across) 
first developes the marginal teeth, leaving the central ones till 
it gets older. The anterior portion of the shell also is of abnor- 
mal size. 

The longest specimen measures long.2'77, Za^. 3"58, alt.l'Q. 
A transverse specimen ,, ,, 1'94, ,, 2'54, ,, 1"14. 

A rounded specunen ,, „ 1"62, „ 1'87, ,, 1'03. 

Hab. — St. Elena, in sandy mud, 6 fm., Cuming. — Ecuador : 
St. Elena, D'Orhigny. — Taboga, very^ rare, C. B. Adams. — 
La Paz, Lieut. Green.— S. W. Mexico, P. P. C— Found 
abundantly at San Bias and Mazatlan, Lieut. Belcher. — 
Mazatlan, common ; L'2)ool Sf Havre Col. — (D. elegans) 
Philippines, Cuming. — Swan Eiver, N. H., Philippi. 
Tablet 272 contains 11 small perfect and imperfect valves 
which probably belong to this species. 



(^6 MAZATLAN BIVALVES 

Tablet 273 contains 7 sp. of various ages, biradiate. — 274, 2 
do. gibbous. — 275, 2 do. uniform dark broAvn. — 276, 1 do. trans- 
verse, very dark brown. — 277, 6 do. and 2 valves, rather dark, 
not biradiate.— 278, 6 do. liglit gray. — 279, 3 do. very light, 
faint rays, young shell speckled. — 280, 2 do. greenish tinge. — 
281, 1 do. purplish. — 282, 4 do. concentrically banded with 
reddish. — 283, 4 do. and a young valve, spotted, fonii like D. 
maculata. 



94. DiOjsrE KOSEA, Brod. Sf-Sow. 

Cytherea rosea, Zool. Journ. iv. 364. — Zool. Beech. Toy. Moll. 
p. 151, pi. 43, f. 7.— Hani. Beser. Cat. p. 104 : WoocVs Suppl. 
pi. 9, f. 11.— P/i/7. Abbild. Conch, p. 183, pi. 5, f. 6.— Sow. 
Tlies. Conch, p. 632, p. 132, f. 108. 
Dione rosea, Desk. B. M. Cat. Ven. p. 77, no. 71. 
Cytherea lex^ida, Chenu, Conch. HI. 

Shell as usual, either more or less produced posteriorly, or 
swollen ventrally ; but In all varieties known from D. lupinaria 
1. by the non-development of spines, which alone might be 
accidental ; 2. by the shape, which is much flatter, and gener- 
ally more produced ventrally ; 3. by the coloiu-, in which pink- 
ish brown rather than piu'ple predominates, being imiform 
over the whole shell ; a white streak going along the line of 
spines without purple at the bases, and a brownish instead of 
purple patch covering the lunvdar portion ; 4. by the anterior 
lamina;, which instead of being close togeth'er, are only raised 
here and there, generally at iuteiwals of 4 or 5 ; 5. by the 
longer ligament, which is enclosed by a finer ridge, scarcely 
conspicuous in one valve ; 6. by the absence of the line mark- 
ing the second row of spines and angulating the posterior 
margin ; 7. by the teeth which are less raised, more spreading. 
The colour within is white with difl\ised violet, not predominant 
at the huige. Extremely rarely there is an attempt at the 
formation of a kuol) or two where the second row should be, 
but never a marking line. The concentric ridges are fine, 
nearly equal, and rarely evanescent ventrally. The ridge which 
bears the raised lamina does not neeessavily bear the raised 
knobs. The ridges sometimes bifurcate, but are generally more 
parallel to the margin than in D. lupinaria. I have examined 
above 5(X) specimens, in which I believe the above characters 
are constant. A large number of them are pierced by preda- 
cious gastcropods. 



MAZATLAN BIVALVES 67 

The largest specimen measures Zow//. 1" 97, led. 2'd8, cdt.1'06. 

A transverse specimen „ ,, 1'72, „ 2'11, „ '87. 

Hab. — Found abundantly at San Bias, Lieut. Belcher, (Beech. 

Voy.) — Panama, Cuming (teste Sow. : non C. B. Ad.). — 

Mazatlan ; abimdant ; Upool ^ Havre Col. 

Tablet 284 contains a minute valve, probably belonging to 
tliis species, measm*ing "06 across. 

Tablet 285 contains 7 specimens, normal type. — 286, 5 do. 
dark coloured, transverse. — 287, 3 do., brownish tinge. — 288, 
3 do. lamina; slightly raised ; the largest was attacked by a 
gasteropod, who left his hole imfiuished. — 289, 3 do. pinker 
shade. — 290, 3 do. more produced ventrally. — 291, 3 do. most 
produced.— 292, 3 do. coarse ribs.— 293, 3 do. very pale. 



95. Dio>rE LUPiNAEiA, Less. 

Cytherea lupinaria, Less. Cent. Zool. p. 196, pi. Q4s.—Sow. Tlies, 

Conch, p. 632, f. 111. 
Venus lupanaria, B. M. Cat. HOrh. Moll. p. 67, no. 593. 
Chione lupanaria. Gray Anal. viii. 306. 
Dione lupanaria, Besh. B. M. Cat. Ten. p. 76, no. 68. 
Cytherea Dione, var.. Brod. Proc. Zool. Sac. 1845, p. 45-6. — 

Gra?/ in Grijf. Cuv. An. King. pi. 19, f. l.—Rve. Conch. Syst. 

i. 95. pi. 71, f. 1. 
Cytherea semilamellosa. Gaud, in Deless. Rec. pi. 19, f. 2. — 

Chenu. Conch. III. pi. 9, f. 9. 

This shell is sometunes shaped like its well known W. Indian 
analogue, V. Dione, Lin. (Dione Veneris, Desh.) : but is almost 
always larger and more transverse. It is known at once by 
the concentric ridges, which are never sharp and raised as in 
D. Veneris, but either rounded or sub-obsolete on the ventral 
part. Many of them (generally every other, or 1 out of 3) 
become obsolete before reaching the anterior part ; the remain- 
der become sharply lamellar, gradually fading off to the hmule, 
not suddenly ending there as in D. Veneris. The posterior 
part has two angular swellings, one in the line of the inner 
spines, the other just beyond the ligament. The inner area, 
limule and bases of spines are almost always purple even in 
the pale variety. There are all shades of colour from white to 
rich puse or purple. The spines appear very irregularly, 
sometimes two or more gi-owing together, sometimes leaving a 
large space without. The young shell has always two rows, 



68 MAZATLAN BIVALVES 

the inner one tiirned backTvard- In the adult, this row ceases. 
The very- young shell has none ; while in D. Veneris they ap- 
pear much earlier. The spines in the large row are generally 
rather sti'aight and very long; one measured long. 1'8S, and 
others must have been longer when perfect. The concentric 
ridges are not always parallel with the margin of the shell, and 
often bifurcate very irregularly. I have examined carefully 
nearly 4,000 specimens, almost all of which had fallen victims 
to the voracious apijetites of gasteropods, who drill their holes 
generally near the apex. Epidermis extremely thin : spines 
channeled. The spine of the smallest weU marked specimeD 
measures '41; the sheU itself Zo«(/. '49, lat. '59, alt. '31. 
The largest (without spines) „ 2-26, ,,2-77, „ 1"5. 
The most transverse ,, 1'53, „ 2'06, ,, 1'03. 

Sab. — Salango, in sandy mud, 9 fm. ; Timibez (Peru) soft mud, 

5fm. : Cuming.— San Bias (Culf of California), sandy mud, 

7 fm., Col. Cuming. — Payta, (Peru,) D'Orbign//. — Mazatlan; 

Col. Jeweit, (Gould ms.) — Do; extremely abundant, i'jJooZ 

^ Savre Coll. 

Tablet 294 contains 2 minute valves, (the smallest '025 
across,) which probably belong to this species, though they 
shew no trace of spines. 

Tablet 295 contains 9 very yoiing specimens, rounder form, 
with rather coarser strife. — 296, 6 do. rather older. — 297, 3 do. 
adolescent. — 298, 2 do. very large. — 299. 9 very young, trans- 
verse form. — 300, 8 do. rather older. — 301, 6 do. adolescent. — 
302, 3 do. adult.— 303, 5 young, pale var.— 304, 3 do. adult.— 305, 
4 sp. -ndth extra spines. — 306, 1 large do. shewing epidermis. — 
307, 3 young, spines forming at margin. — 308, 3 do. spines 
strangely curved. — 309, 2 do. small spine growing by and in 
broken large one. — 310, 1 adult, with spurs on bottom of 
spines. — 311, 1 do. two spines growing together. — 312, 1 do. 
very crowded spines at margin. In all, 72 specimens. 

96. DiONE ? VULNEBATA, Brod. 

Cytherea vulnerata, Proc. Zool. Soc. 1835, p. 46. — Sanl. Deso: 

Cat. p. IQ^.—Catlow. Cat. p. 40, no. \\Q,.—Sow. Thes. Conch. 

p. 632, pi. 131, f. 95, 96. 
Dione vulnerata. Desk. B. M. Cat. Ten. p. 60, no. 15. 

Tablet 313 contains 2 minute opposite valves which may 
belong to this species. 
Hah. — Eeal Llejos, in sandy mud, 6 fm. Cuming. — ? Mazatlan ; 

2 valves oflf Spondylus ; L'pool Col. 



MAZATLAS^ BIVALVES 69 

97. DiONE ? BEEVISPINOSA, Sow. 

Cytherea brevispinosa, Sow. T/ies. Conch, p. 632, pi. 132, f. 109. 
Dione brevispinata, Des/i. in B. 3f. Cat. Ven. p. 76, no. 70. 

Tablet 314 contains a minute valve wMcli may be the young 
of tbis species. It has close concentric rounded ribs, and very 
strong teeth for the size. Length '03. 

J3a5. — Gulf of California, Col. Cuming. — PMazatlan, jun. 
1 valve ; L'pool Col. 

98. Dione ciecinata, Born. 

Venus circinata. Bom, Test. Mas. p. 61, pi. 4, f. S.— Ckermi. 

Condi. Cab. vi. 312, pi. 30, f. Sll.—BiUw. Bee. Sk. i. 169.— 

B. M. Cat. Sagr. Moll. p. 39, no. 474. 
Cytherea circinata. Sow. Thes. Conch, p. 631, pi. 132, f. 104-6.— 

Forbes ^ mini. Br. Mol. i. 399. 
Dione circinata, Desh. B. M. Cat, Ven. p. 77, no. 72. 
Venus Guineensis, Gmel. Syst. Nat. p. 3270, &c. 
Cytherea Guineensis, Lam. An. s. Vert. ed. Desh. vi. 311, &c. 
Cytherea alternata, Brod. Proc. Zool. Soc. 1835, p. 4-5. 

Tablet 31.5 contains a small white valve -nhich may be the 
young of this species : long. "08, lat. '095, alt. "05. 
Hah.— Cuha., Sagra.—S. Atlantic, Forbes.— Jlazatlan, CajJt. 

Donnel :— do. Lieut. Green, (Gould ms.) :— do. one valve and 

fragments, jun., L'2}ool Col.—V&r. alternata, Monte Christi, 

in sandy mud, 11 fm., Cuming. 

99. DiONE CONCINNA, SotO. 

Ci'therea concinna, Proc. Zool. Soc. 183-5, p. 2'i.—Soiv. Thes. 

Conch, p. 630, pi. 132, f. 99, 100. 
Dione concinna, Desh. B. M. Cat. Few. p. 74, no. 61. 
Comp. D. affinis, Brod. Proc. Zool. Soc. 1835, p. 45 ; 5 3L 

Cat. Ven. no. 60 : and D. tortuosa, Brod. id. ; B. M. Cat. 

Ven. no, 62. 

This shell is coloured in sienna brown and white stripes in 
about equal proportions, the brown being darker on the ribs 
and in the lunule. Umbos yellow. Concentric ribs occasionally 
bifurcating. Pallial sinus, long, narrow, ascending. Long.\-2 
lat. 1-.56, alt. '75. 

^«i.— Panama, in fine sand, 10 fm. C«7«7'»(/.— Mazatlau ; 1 sp. 
with D. rosea ; L'pool Col. 
Tablet 316 contains the specimen. 



70 MAZATLAN BIVALVES 

Genus CYTHEEEA, Lam* 

Cytlierea, ex parte, Lam. 1809, et aicct. 

Meretrix, Lam. 1799 ; Desk. B. M. Cat. Yen. p. 34. 

This gemis, as restricted, is known by tlie subtrigonal form, 
crenated posterior and distant anterior tootb, and the verj- 
small pallial sinns. 

100. Cttheeea petechialis. Lam. 
Lam. An. s. Vert. ed. Desk. vol. vi. p. 2m.-Soto^ Gen f. L- 
Hanl. Descr. Cat. p. 96 -.— Wood Suppl. pi. lo, i ^-—-^Jl^- 
Conch. Sfjst. vol. i. pi. 69, 70, f. l.-l Sow. Tlies. Conch, p. 619, 

pi. 129. f. 51. n . . T. 7 X. ir 

MeretrLx peticliialis, Bnc. Meth. pi. 268, f. o, Q>.-Besh. B. M. 

Cat. Veil. p. 36, no. 4. 

Tlie widelv extended form to wliicli tkis slieU belongs was 
distributed bV Lam. imder the species lusoria, peticliialis^ im- 
pudica. castauea. zonaria var. 1, meretrix and grapliica.— l>esti. 
in Lis edition of Lamarck regarded the 6 last, and C. lusoria 
probablv. as aU varieties of one species, differmg only m colour, 
and displaying insensible gradations even m tins, in me 
B M Cat Ten. however he pubhshes them all as distinct ^ex- 
cept meretrix which is merged into M. impudica), along witii 
C. fusca, Koch in Phil. Ahhild. Conch, p. 19, pi. 3 f- l--^^^:^- 
unites C. graphica with C. petichialis, C. fusca with C. lusoria, 
C. castauea with C. impudica, adding C. formosa on Jus own 
authoritv, and yet "being almost persuaded that all these, 
along ^th C. meretrix, morphina, zonaria, casta and o^^lm 
Hani "might be united under one name, seemg that tliey 
pass imperceptibly into each other, and that i^^a young state 
it is almost impossible to distinguish them." H the varieties 
would arran-c themselves into zoological provinces, there 
would be more hope of finding specific types ; but I am unable 
to find auv difference between the Mazatlan shells and those 
from the China and Japan seas. I found scarcely a dozen 
specimens in the D. ehiona^a box of the Liverpool collection ; 
but several more were seen mixed with the other Mazatlan 
sliells in the shop of a dealer who had surreptitiously obtained 

• The laiuiliar Lamarckian name ("nom plus <;o°^enable,"2>»m) is retained 
because a man oufjht to be aUowed to alter his own work ,f he can '"iprove^t 
as be certainly did in this instance, by rejectnig a meretricious °a "f/'^r f " ';'f *"" 
tU-ul a sro^p of shells. There is nothing iiucSaste in nature : it is onh mans 
corrupt idcis that see unclean images m the purity of God s works. 



MAZATLAN BIVALVES 71 

no inconsiderable a portion of the collection.* These shewed 
great diversities of colouring ; sometimes abounding in the 
typical dots, sometimes shewing the faintest traces of them. 
The dots were scarcely ever augulated, according to the de- 
scription and figures of Sow. The favourite trifurcate white 
mark at the umbos sometimes darts up long angular rays ; in 
other cases it is extremely small and irregular. Long. 2" 5. 
lat 2-9, alt. 1-4. 

Hob. — Indian ocean, Lamarck. — China, Deshayes. — [? C. gra- 
phica] Japan, Dr. Sihbald, Mus. Cuming. — Mazatlan, very 
rare ; L'pool Col. 

Tablet 317 contains 5 young valves, from the Chama and 
Spondjdus washings, the larger of which I think certainly, the 
rest perhaps, belong to this species. 

Tablet 318 contains 2 adidt specimens, one of which at least 
was from the box. 

Genus VENUS, Linn. 

Venus, ex parte, Linn., Lam., et auct. 

Chione, Megerle, 1811; Gray, 1847; Desk. B. M. Cat. Ten. 
p. 118 ; (non aray, 1838.) 

101. Venus (Chione) gnidia, Brod. ^ Soio. 

Venus gnidia, Zool. Journ. iv. 364. — Rve. Conch. Syst.. pi. 68, 
f. 5. — .'' Gray in Zool. Beech. Voy. x)l. 41, f. 3. — Deless. Bee 
de Coq. pi. 19, f. 1, a, b.—Hanl. Descr. Cat. p. 113, pi. 13, 
f. 43 : Wood's Supiil. pi. 13, f. 43.— Sow. Thes. Conch, p. 709. 
pi. 154, f. 2b.— B. M. Cat. D'Orh. Moll. p. 68, no. 606.— 
C. B. Ad. Pan. Shells, p. 269, no. 4:37. 
Chione gnidia, Desh. in B. M. Cat. Ven. p. 132, no. 41. 

This queen of Veneres flourishes in the greatest luxuriance 
and magnificence in the Mazatlan seas. Though the texture is 
not so delicate as that of Ch. amathusia, nothing can exceed the 
beauty of the concentric frills, which rise at various intervals 
generally perpendicvUar to the surface of the shell. On the 
back, they carrj' off the radiating furrows : on the front they 
are beautifully crenated. They generally rise into lamin;p 
(sometimes "23 long) which are occasionally bent up almost 

• Before I knew how much the species was divided, I distributed under this 
name in several of the Mazatlan collections (" Hab, incog.") specimens which 
properly rank under one of the other groups. 



72 MAZATLAN BIVALVES 

into a tube. Tlie epidermis is extremely thin, but important 
to preserve the shell, which soon becomes of a calcmed appear- 
ance without it. The radiating striaj become obsolete m the old 
shells, but not so much so as in Ch. amathusia. The snraUest 
valve measures 'OS in length : the largest specunen, long.3-5, 
lat. 3 '56, alt. (without spines) 2*3. 

JT«6.— Payta, Peru, Fontaine, D'Orbigny.— Panama, rare, C. B. 
Adams!— S3.VL Bias, Jay.— Mazatlan ; Lieut. Green, (Grould 
ms.) ; extremely abundant ; Lpool Sf Havre Coll. 
Tablet 319 contains 3 very young valves.— 320, 4 young 
specimens, form somewhat rounded.— 321, 3 do. adolescent.— 
322, 3 do. adult.— 323, 3 young, slightly produced.— 324, 3 do. 
adolescent.— 325, 2 do. adult, ribs close.— 326, 3 do. young, 
more produced.-327, 2 do. adult.-328, 4 young, rather flat- 
tened, with distant laminae.— 329, 3 do. adolescent.— 330, 2 do. 
adult.— 331, 5 young specimens set to shew the ventral margin 
in different stages of growth.— 332, 4 do. adolescent.— 333, 4 do. 
adult.— 834, 2 sp. shewing the nearest approach to Ch. amathusia, 
and unnatural longitudinal grooves.— 335, 1 sp., ribs not foli- 
ated ventrallv.-336. 2 do., ribs flattened.-337, 1 do., strongly 
foliaceous.— 338, 1 do., foliations semispmous.— 339, 1 sp. de- 
formed growth.— 340, 3 do. with irregular ribs, in aU 59 
specimens. 

102. Venus (Chione) amathusia, Phil. 

Venus amathusia, Fhil. AhhiU. p. 129, pi. 2, f-i--p- -5- ^^ 

Pan. Shells, p. 269, no. 435.— Soio. Tlies. Conch, p. 709. 

pi. 154, f. 26, 27. ^ 

Chione gnidia, var. Desh. B. M. Cat. Yen. p. 133, no. 4L. 
+ Chione amathusia, i)e.9/<. (/o. p. 132, no. 39. 
?= Venus cancellata, Metike in Zeit.f.Mal. 1847, p. 191, no. 

58, (non Lam.) ■ ,^j i •• 

? = Venus suecincta, Val. iu Riimh. Bee d Ohs. vol. n. 

I foUow Hani. Sow. and ? C. B. Ad. m regarding this as 
Philippi's species. It agrees exactly M-ith the description ; not 
with the figure. I have however a very worn young stunipy 
specimen from S. W. Mexico, which is sufficiently like the 
figure especiaUr when it is remembe-ed that figures are not 
always like the shell. I cannot say that I should have known 
it even from Sow.'s figure, which is much better. Desh. re- 
gards Phil.'s species as distinct, and (with Dr. Gray) considers 
this a variety of Ch. gnidia. What changes the creatures make 



MAZATLAN BIVALVES 73 

in other places I do not know, except from the picked spa*-- 
mens in Mr. Cuming's Col. He regards the species as distinct. 
The Mazatlan shells would never have encouraged any one to 
unite them : neither Collector nor dealers oflFered to put them 
together. I have very narrowly examined about 400 specimens 
of this shell, and more than 600 of Ch. gnidia, nor did I find a 
single intermediate form. The texture of the shells varies 
as earthenware from china ; Ch. amathusia under the epidermis 
being glossy, and of a very light brownish purple ; Ch. gnidia in 
the same circumstances having the appearance of a baked shell, 
didl, and of a darker brown. The concentric ribs are peculiarly 
lustrous, and are very short and stumpy, rarely shewing any 
tendency to rise into scales. The radiating strise are very 
much famter, shewing a disposition to gather in twos in the 
yoiuig shell. The lunular portion is much larger, smoother, 
and of a richer purple. Both species within shew the middle 
teeth slightly furcate, the paUial li:ie distant from the margin, 
and the sinus small. Ch. amathusia is generally smaller, more 
swollen, with a thicker shell and margin ; and is more angula- 
ted posteriorly. It is represented by Ch. caucellata in the 
Caribbtean sea, and its yoiuig may be the shell so named in 
Menke's Mazatlan list. The smallest specimen found is 1'5 
In. long ; the largest measures long. 2'43, lat. 2'74<, alt. l'6o. 

Hab. — ? Panama, very rare, C. B. Adams. — S. W. Mexico, 
P. P. C. — Mazatlan; Lieut. Green, (Gould ms.) — Do. ; com- 
mon and very fine ; L'^iool ^ Havre Coll. 

Tablet 341 contains 3 specimens, rounded form. — 342, 3 do. 
more angidated. — 343, 3 do. close ribs. — 344, 3 do. produced 
posteriorly. — 345, 3 do. distant ribs. — 346, 3 do. swollen form. — 
:ii7, 3 do. produced. — 348, 3 do. even growth. — 349, 1 do. witli 
irregular ribs. In all 25 specimens. 



103. Venus (? Chiome) , sp. ind. 

This can scarcely be the young of Cli. amathusia, since the 
sliape is very diflferent, being sulxpiadrate. Surface more or 
less distuactly marked with fine concentric ridges and radiathig 
striffi, so]netimes nearly smooth ; lunide cleai'ly marked ; an- 
terior tooth rather long ; xiaUial line distant from margin ; 
sinus broad, shallow. Colour i)ink or light green. The largest 
specimen measxires lo?ig. '09, lat. '12, alt. '06. 
Oct. 1855. h 



74 MAZATLAN BIVALVES 

Hal. — Mazatlan ; about a score were found in the dirt from 

the small Olivae ; L'pool Col. 

Tablet 350 contains 4 pairs decussated. — 351, 1 pair and a 
valve, concentric ridges predominant. — 352, 2 pairs, nearly 
smooth. 



104 Venus (PChione) distans, PJdl. 

Venus distans, FMl. in Zeit.f. Mai. 1851, (Cassel 1852) p. 126. 
? Chione distans, Desk. B. M. Cat. Ven. p. 123, no. 13. 

Tablet 353 contains a worn valve, with 2 stout concentric 
ridges, which comes nearest to this species. Length '07. 
Hah. — Panama, E. IB. Philippi. — ? Mazatlan, 1 valve off Spon- 

dylus ; L'pool Col. 

105. Venus (Chione) ceenifeea. Sow. 

Venus crenifera ; Proc. Zool. Soc. 1835, p. A3.— Hani. Bescr. 

Cat. p. 118 : Wood Suppl. pi. 16, f. W.—B. M. Cat. D'Ovb. 

MoU. p. 67, no. 603.— &?t'. Thes. Conch, pt. 14, pi. 156, 

f. 73, 74. 
Chione crenifera, Bcsli. B. M. Cat. Ven. p. 136, no. 50. 
? = A''. elevata, Say teste Sow. 
.?=V. radiata, Chcmn. t. 36, f. 386, teste Soio. 
=V. portesiana, UOrh. Voy. Am. Mer. Moll.^.hh'6, pi. 83, 

f. 1, 2, teste I>esh. 

This shell belongs to a group of closely allied species, one of 
which is from the W. Indies. I am not sure that it is rightly 
named, but I follow Mr. Eoeve's authority. It fits the original 
description, as others might, but not the figiire or notes in 
Sow.'s Thes. Conch. The radiating lines scarcely ever group in 
threes ; the shape is suboval, scarcely beaked ; the dorsal area 
is nearly smooth ui one valve, but viith the concentric ridges 
continued over in the other, whiclx overlaps beyond the liga- 
ment. Surface very irregularly spotted with light chocolate 
brown. Concentric ridges (wliich are more or less close) 
strongly indented and rather glossy. Pallial sinus smaU, sub- 
oval.— Anterior tooth prolonged, sharp: cardinal,^ sub-bifid. 
Largest specimen (worn) measures long. 1"6-1., lat. 1'87, alt. 1'08. 
JETaJ.— St. Elena, in sand at low water ; var. Payta (Peru) ; 

C«??i?'nf/.— Payta, D' O/'i/j//?^.— Mazatlan : extremely rare; 

TJpool Col. 



MAZATLAN BIVALTES ' 75 

Tablet 354 contains a minute valve, long. "05, and some frag- 
ments. — 355, tlie most cliaracteristic specimen. 

106. Venus (Chione) Ptjndatella, Sow. 

Venus undatella, Proc. Zool. Sac. 1835, p. 22,.— Hani. Descr. 

Cat. p. 117.— -Sow. T]ies. Conch, p. 711, pi. 153, f. 22. 
Chione undatella, Besh. B. M. Cat. Ven. p. 141, no. 68. 

Tablet 356 contains a broken very young sbell whicb may 
belong to tbis species. Concentric ridges numerous ; radiating 
costae just beginning to sbew near margin : anterior tooth pro- 
longed, as usual in young sbells. Long. '04. 
Hah. — On tbe shore. Isle Tres Marias, Gulf of California; 

Col. Cuming. — PMazatlan; 1 valve, off Spondylus; L'pool Col. 

107. Venus (Chione) Columbiensis, Soto. 

Venus Columbiensis, Proc. Zool. Soc. 1835, p. 21. — Hani. 

Descr. Cat. p. 119: TFood Suppl. pi. 16, f. 2.— -Sow. Tkes. 

Conch, p. 713, pi. 155, f. 53, 54— jB. ilf. Cat. B' Orb. Moll. 

p. 68, no. 611. 
Chione Cohunbiensis, Desh. B. M. Cat. Ven. p. 136, no. 53. 

Shell remarkably solid, with strong ligament; with deep 
radiating grooves leaving broad flattened ridges which are 
crossed by fine concentric ridges, sHghtly elevated, rising and 
falling with the furrows, rather in'egular, evanescent on the 
ventral portion, and nearly so on the posterior, where the ribs 
often rise into scales on the line of the ridges. The shells often 
show here and there concentric risings of growth, the fresh 
shell being commenced below the other. In one valve the 
posterior rib is very large, overlapping the other valve beyond 
the ligament. Lunule defined by a deeply cut line, swollen in 
the middle, and bent at the margin. In these points, and in 
the character of the hinge, this species closely resembles Ch. 
verrucosa ; the pallial sinus however is somewhat larger. In 
more than half the specimens, the prevailing colour is choco- 
late brown ; in the remainder, yellowish white more or less 
tinged with patches of puri^bsh brown. The young shell is very 
often white, tipped at the umbos with pink or brownish purple. 
The smooth ligamental area is always spotted with puri)le. In 
the very young shells [?] the concentric ridges are not seen ; 
afterwards they often go nearly across. Colour inside, white, 



76 StAZATIAN BIVALVES 

often purple, especially on the hinge line. The smallest valve 
is '03 across ; the largest measures long. 1"9, led, 2", alt. 1'28. 
Hah. — St. Elena, in coarse sand at low water, Cuming. — 

Ecuador ; St. Elena, D' Orbigni/.—S. W. Mexico, P. P. C— 

Mazatlan ; extremely common ; L'pool Sf Havre Coll. 

Tablet 357 contains 7 young valves, [?], lunule not defined, 
very faint concentric lines of growth, anterior tooth elongated, 
as is usual in young Venends. 

Tablet 358 contains 7 specimens of the normal chocolate 
colom*. — 359, 7 do. with white umbos. — 360, 7 do. purplish 
tinge. — 361, 7 do. light coloiu-ed, shghtly spotted.— 362, 7 do. 
with large patches of dark. 

108. Venus (? Chione) , sp. ind. 

Tablet 363 contains 3 small valves, the smallest only '02 
across, smooth and white, which do not accord with any of the 
foregoing species. 
Hab. — Mazatlan ; in shell washings : L'pool Col. 



Genus TAPES, Megerle. 

This genus, though the tji>e of a sub-family of Gray, (5. M. 
Cat Ven., p. 159) approaches Yeuus (Chione, Ifegerle, G>'a>/J 
by insensible gradations. The following species may be ranked 
with either genus. The t:\T)ical forms have not yet been found 
in this Zoological province. 

109. Tapes histeionica. Brad. Sf Sow. 

Venus histrionica Proc. Zool. Soc. 1835, p. 41.— Saul. De.scr. 

Cat. p. 119 ; Wood. Suppl. pi. 16, f 31.— i?. M. Cat. D'Orh. 

Moll. p. 67, no. 59L—SoK'. T/ie.9. Conch, p. 714, pi. 55, f 52. 
Chione histrionica, Desli. B. 31. Cat. Ven. p. 139, sp. 60. 
Tapes histrionica, Hani. Col. siio. 

This belongs to a group of verj' closely allied species, of 
which T. granulata {B. 31. Cat. Ven. p. 138,) is the W. Indian 
analogue, and T. straminea the Cahfornian. It has the form 
and sculpture of a Tapes, with the teeth and pallial sinus of a 
Venus. The form varies in the greater or less development of 
the posterior angle, and in tlie flattening or rounding of the 






IIAZATIAX BIVALVES 77 

ventral margin. Tlie coloiu' is ver\- liglit brown, more or less 
spotted or stained witli darker in zigzag stripes or blotches. 
Tbe ligamental area is smooth, and marked off by a decided 
keel on each side. The keel is almost always painted with spots, 
even when the rest of the shell is without them. Long. 1 " 34, 
lat.VoS, alt. -8. 

Sah. — Real Llejos & St. Elena, in mviddy sand at low water, 
Cuminfj. — Ecuador, St. Elena, D'Orhigny. — Mazatlan ; ex- 
tremely abundant ; Upool ^' Havre Coll. 
Tablet 364 contains 7 specimens with dark patches of brown. — 
36-5, 7 do. smaller patches. — 366, 7 do. very small j)atches. — 
367, 7 do. dark markings obsolete. — 368, 7 do. with generally 
diffused shade of Ughter brown. — 369, 7 do. the same broken 
up into patches. 

110. Tapes geata. Say. 

Sow. Tlies. Conch, part 13, p. 699, pi. cli., f. 152 : (non Desk, in 

B. M. Cat. Yen. p. 170.) 
Venus grata, Say Am. Conch. 1830, pi. 26 (teste Jay, 36 teste 

Sow.) 
Chione grata, Desh. in B. 31. Cat. Ten. p. 140. 
= (teste Desh.) Venus tricolor, Soic. Proc. Zool. Soc. 183-5, 

p. 41. — 2k)ol. Beech. Toy. p. 1-51, pi. 41, f. 7. — Hani. Descr. 

Cat. p. 119 .• Wood Suppl. pi. 16, f. 32.— (Tapes t.) Sou: Tkes. 

Conch, p. 699, pi. 151, f. 1-53. 
= (teste Jav) Venus discors, Soic. Proc. Zool. Soc. 1835, p. 42. — 

Hani. Descr. Cat. p. 118 : Wood Siippl. pi. 15, f. m.—B. M. 

Cat. B'Orh. Moll. p. 67. no. 600.— C. B. Ad. Pan. Shell s, 

p. 269, no. 4:36.- (Tapes d.) Sow. TJies. Conch, p. 698. pi. 151, 

f. 148-150.— (Chione d.) Desh. B. M. Cat. Yen. p. 141, no. 65. 
? = Venus Entobapta. Jonas Zeit.f. Mai. 1845, p. 66. 
? = Venu3 neglecta, Phil. Ahbild. ii. 62, pi. 4. f. 3, (non Gray.) 

This shell differs from T. histrionica in not having the smooth 
ligamental area nor the enclosing carina?. The kmule also is 
less distinct. The large specimen is much more tumid, and 
more irregularly marked. The hinge teeth are much closer 
and smaller in proportion, and are very slightly bifid. — PaUial 
sinus less angulated, smaller. Internal crenations less distinct. 
An intermediate specimen has one tootli in each valve strongly 
bifid, and is flattened Hke T. histrionica. The younirest speci- 
men scarcely displays bifidity, is much more coarsely and 
regTilarly marked, and has the paUial sinus rounder. It is 



78 MAZATIAN BIVALVES 

possibly a distinct species, and closelj'' resembles the W. Indian 

T. granulata. Tbe largest measures long. 1'5, lat. 1'66, 

alt. 1-06. 

Sah.— W. Coast Mexico, Say— S. W. Mexico, P. P. C— 
Mazatlan, 3 specunens with T. bistrionica, L'pool Col.— 
(T. discors) St. Elena and Guacomayo, in sandy mud, 6-9 fm., 
C;««/;3(7.— Ecuador, St. Elena, D' Or J/(7«y.— Panama, Jeiceit, 
(Gould ms.) — ? Do. : common, C. B. Adams. — Gu&jm&s, 
Lieut. Green. (Gould ms.).— (T. tricolor) Puerto Portrero, in 
sandy mud, 11-13 fm. Cuming. 
Tablet 370 contains tbe small specimen ; and 371, the largest. 

Ill, Tapes squamosa, n. s. 

T. t. parvd, subquadratci, oblongd, alhd fusco maculata ; 
margine dorsali siihrecto, postice angulato ; costis fortihiis ah 
umhone prominente radiantihus, liris concentricis parte anteriori 
etveniraU decussatis ; parte posteriori liris ohsoletis, costis 
ibi inter ruptis, squamosis, maxime costa ligamento 
proximd; dentihus 2-3 cardinalibus divergentihm ; sinu 
pallii subovali ; lunula impressd. 

Eemarkable for the strong radiating ribs, broken up into 
scales posteriorly which are very large on the rib next the 
ligament. On the body of the shell these are decussated with 
moderately distant raised concentric lines. The young shell 
has in one valve a long posterior lateral tooth close to the liga- 
ment. This shell measures long. "OS, lat. -04 ; the largest valve 
long. -09, lat. "115, alt. 'Oo. 
^„5,_]\Iazatlan ; from washings of Chamse and Spondyli ; 

extremely rare ; I! pool Col. 

Tablet 372 contains the only 3 valves found. 

Genus AI^OMALOCAEDIA, Klein. 
Anomalocardia, ScJium. 1817, Essai d'une Mith. p. \U.—Besk. 

B. M. Cat. Yen. p. 115. 
Triquetra, Blainv. 1818. 
Cytherea, sp. Lam. 
Venus sp. Sow. Phil. &c. 

This small group of Venerida^, consisting of species classed 
sometimes ^\-ith Venus, sometimes with Cytherea, is weU char- 
acterized by its irregular growth and extremely smaU paUiai 
sinus. 



MAZATLAN BIVALVES 79 

112. Anomalocaedia subetjgosa, Sotc. 

Venus subnigosa, Soio. Gen. f. 2.— Eve. Conch. Si/st. i. pi. 67, 
f. 2.—Sanl Bescr. Cat. p. 116 -.— Wood Suppl. pi. 2, f. 6.— 
Phil. Abhilcl. Conch, p. 177, pi. 3, f. 6, l.—Soio. Thes. Conch. 
p. 721, pi. 155, f. 63.-5. M. Cat. D'Orb. Moll. p. 67, 
uo. 595.— a B. Ad. Pan. Shells, p. 271, no. 440. 
Anomalocardia subnigosa, Desh. B. M. Cat. Ten. p. 116, no. 2. 
= Cytkerea subsulcata, Menke, in PA/Z, ^5JjW. (ad fid. spec, 
ab ipso accept.) 

Tbis very variable shell is represented on the Atlantic coast 
by A. flexuosa. It is very coarse and beavy ; generally worn 
at the umbos. The earlier part of the shell is covered by 
irregular concentric swelluigs, which afterwards become eva- 
nescent on the ventral portion, sometimes all over. These are 
crossed by rather deeply cut fine radiating lines, which are 
generally strongest in the depression which marks off the 
posterior beak, rarely becoming xjunctato-striate. This depres- 
sion however often nearly disappears, and the shell approaches 
A. subimbricata in form. Sometimes it is much flattened, some- 
times remarkably swollen and gibbous ; sometimes very trans- 
verse, sometimes much produced ventrally. The radiating 
grooves sometimes cover the flattened ventral margin, which 
is very finely crenulated within. The lunule is marked by a 
well-defined Une, and nearly smooth. The teeth and ligament 
are very strong. Colour generally a yellowish or bro-miish 
white.'almost always with 2-4 (generally 3) more or less broad 
radiating brown stripes ; and the rest often freckled with dots 
or broken hues. Inside generally with a purple stain about 
the hinge. Epidermis very thin, very pale or brownish. 
A transverse specimen measures ^?»5'. 1 ■ 3, lat.\'T2, alt. '88. 
An elongated „ „ „ 1'49, „ 1*78, „ 1. 

A thick „ „ „ 1-48, ., 1-88, „ 1-2. 

Ha5.— Panama, Hanley.— Peru, D'0/-5?>»y.— Panama; partly 
buried in coarse sand among atones or under ti-ees, near half 
tide level, rare ; C. B. Adams.— ^. W. Mexico, P. P. C— 
Mazatlan ; in extreme profusion ; L'pool Sf Savre Coll. 
Tablet 373 contains 1 minute valve "6 across.— 374, 6 young 
specimens, usual state.— 375, 6 do. adult.— 376, 6 do. more 
beaked.— 377, 6 do. more swollen, produced ventrally.— 378, 2 
do. shape of A. subimbricata.— 379, 6 do. more transverse.— 
380, 3 do. very tumid var. rounded.— 381, 6 do. more trans- 
verse.— 382, 4 do. beaked.— 383, 5 do. flattened var., produced 



80 MAZATLAN BIVALVE3 

ventrallj-. — 384, 6 do. rather beaked. — 385, 4 do. more trans- 
verse.— 386, 7 do. transverse form, beak not indented. — 387, 6 
do. very transverse and indented. — Groups shewing colour. 
Tablet 388 contains 2 sp. whitish var. normal. — 389, 2 do. trans- 
verse.— 390, 2 do. flat.— 391, 2 do. tumid.— 392, 3 sp. yeUoivish 
var. normal. — 393, 3 do. transverse. — 394, 2 do. rounded. — 395, 
1 do. tumid. — 39G, 3 do. orange var. — 397, 3 sp. darh var. nor- 
mal.— 398, 3 do. elongated.— 399, 3 do. rounded.— 400, 3 do. 
tumid. — 401, 3 do. form of A. subimbricata. — 402, 3 sp. broad 
bands. — 403, 3 do. speckled. — 404, 3 do. narrow bands. — 405, 2 
do. and a valve, bands very faint. 

Tablet 406 contains 3 sp. strongly rugose. — 407, 3 do. smooth 
form. — 408, 3 do. shewing the inside. — In all 130 si>ecimens. 



113. AXOMALOCAEDIA SUBIMBRICATA, SotV. 

Venus subimbricata, Proc. Zool. Soc. 1835, p. 21. — Wood Suppl. 

App. pi. 15, f. o7.— Soto. Thes. Conch, p. 711, pi. 154, f. 35-38. 
Anomalocardia subimbricata, Desh. B. Jf. Cat. Ten. p. 117, no. 4. 

Only a very few small pairs and some young dead valves 
were found of this species, wJiich fiu'ther south is not uncom- 
mon. These few however exhibited remarkable differences. 
Sometimes the form was regular, sometimes extremely gibbous. 
Semetimes the concentric folds were rounded ; sometimes 
as though the shell was raised at intervals and a fresh shell 
begun below ; sometimes the radiating ribs were crossed by 
angidar lamina?, as in Ch. amathusia and gnidia. In this 
state it may possibly be the V. canceUata of Menke's 3Iaz- 
atlan catalogue fZeit. f. Mai. 1817, p. 191) ; unless indeed 
that be a young specimen of one of the species above named, 
from which it may be told by the extremely minute pallial 
sinus. Very rarely the concentric ridges scarcely appear Lu 
the yoiuig shell, in which state it might easily be taken for 
another sijecies. In one very young specimen, on the other 
hand, the concentric folds are sharp, while the radiating ribs 
are nearly evanescent. The largest specimen only measures 
long. 1-01, lat.Vl, alt. H. 

Hah. — Puerto Portrero, in fine sand, 13 fm. Cuming. — Acapul- 
co, Sowerby. — S. W. ^lexico, not imcommon, P. P. C. — 
Mazatlan ; extremely rare ; L'pool Col. 
Tablet 409 contains 2 minute valves. — 410, 5 valves of various 

forms. — 411, the gibbous specimen. 



mazatlan bivalves 81 

Family ASTAETID^, 

Cyprinidfe, Forbes, Woochc This name lias been previously 
appropriated for a family of Fishes. Gray divides it into 
four families, Carditida, Astartid^, Crassatellidffi, and Glos- 
sidfe (Isocardia, Lam.) 

Genus CIRCE, Schum. 

Cytherea (pars) Lam. — This genus is ranked with the Veneridae 
by Gray Sf Desk., with Astarte and CjTDrina by Forhes and 
Woodv\ 

114. CiECE maegaeita, n. s. 

C. t. minima, suhovali, ineequilaterali, umhonibus appressis, 
suhmgosis, concentrice lirata, liris acutis, area lunulaqiie 
indistinct is, ligamento celato : parte anteriori dilatd, 
posteriori pa)'vd; denfe laterali antic o maximo, altera in 
valvd in cardinalem conjiuente ; postico lomjo, exili : cardinali- 
hus 2-3 ; impressionibus muscularihus, subaqiudibus, linedpallii 
a marcjine remotd ; alhd flavescente, dentibus purpureis ; epi- 
dermide tenui. 

This genus abounds in the Eed Sea, Australia and the East 
Indies generally. It has not been described from the American 
coast. I have several species in a collection sent from the U. S. 
as from S. America ; but as nearly all are identical with Aus- 
tralian species, the locaUty is probably erroneous. The charm- 
ing little C. margarita however establishes its claim to a place 
in the genus, by its appressed, somewhat rugose ximbos, semi- 
internal ligament, large anterior tooth, and the pallial line 
which, though generally indistinct, is certainly not sinuated. 
It is oval, with very clehcate, rather sharp concentric lines, 
covered with a thin epidermis ; sometimes s\ibdiaphanou8, 
sometimes opaque and yellowish inside, with a purple tinge 
on the teeth. It may be the young of a larger species not yet 
discovered, but as about a score of specimens were foimd fresh, 
nearly of the same size, and with the rugose portion of the 
umbos clearly distinguished, it may not improbably be adult. 
Long. -05, lat. "07, alt. -03. 

£«(?».— Mazatlan ; on Spondylus Lamarckii, very rare ; L'puol 
Col. 

Tablet 412 contains 1 pair closed ; 2 do. open, (the largest 
and smallest,) and 1 yellowish valve. 



82 MAZATLAN BIVALVES 



115. ? ClECE SUBTEIGONA, n. S. 



C.t.parva, suhtrigond, po slice longius, margine ventrali 
ovali ; concentrice tenuis sitne st r iatd ; umhoniUis ap- 
pressis, suhrugosis ; Ugamento celato ; dentihcs Jateralihts 
posticis magnis, anticis suhapproximatis ; impressionihus 
muscularihus a margine distantibus ; alho-lutescente, macula 
fttscd postice, intus suhrugosd, et lineis divaricatis hue ef 
illuc picta; epidermide ienui. 

Known at once from C. margarita by its sliape whicli is 
longest behind ; by the very fine concentric strige ; the large 
posterior tooth (not so large however propoii;ionally as the 
anterior tooth of C. margarita ;) and the painting, which dis- 
plays a large irregular brown patch inside, which projects 
somewhat above the regular level and is slightly rugose, and a 
few irregular zigzag lines on a yellowish white ground. I have 
not been able to trace the pallial Ibie. There is no trace of 
sinus, though the colour markings sometimes give an erroneous 
appearance of it. In other respects the generic characters are 
satisfactorily marked. It is somewhat less imcomnion than 
C. margarita, though I found very few fresh specunens. This 
greatly exceeds it in size. Long. '08, lat. ' 11, alt. '04. 

BaJ.— Mazatlan ; on Spondylus Lamarckii, rare ; L'pool Col 

Tablet 413 contains 2 minute valves, cardinal teeth not 
formed ; 2 adolescent and a pair united ; and 2 valves adult. 

Gentts GOULDIA, a B. Adams. 

As I have neither had the good fortimc to find the original 
diagnosis of this genus, nor to meet with any conchologist who 
understood it, I can only guess what it was meant to include. 
The late learned and very accurate Prof. Adams, in his descrip- 
tion of the following species, gives no accomit of the teeth. 
Fortunately however Mr. Cuming possesses and has allowed me 
to examine type specimens of G. parva and Pacifica, received 
from the Professor. The former bears a general resemblance 
to our ? Circe minima : the second is undoubtedly the Mazatlan 
shell, and is like an Astarte with lateral teeth, such as occur in 
not a few of the Crag species. A tliu-d species is now added, 
from its general agreement with the second. 



MAZATLAN BIVAIVES §3 

116. GouLDiA Pacifica, C. B. Ad. 
C. B. Ad. Pan. Shells, p. 275, no. 450, 

The only pair found (and that imperfect) was unfortunately 
smashed just after it had been sketched. It was of a rich lus- 
trous brown like Petricola robusta. The shell has aU shades 
to a dingy white. About 18 odd valves were found, by no 
nieans constant in their characters. The general appearance 
is remarkably like a little fossil Astarte noticed in a communi- 
cation made to the British Association, L'pool, 1854, (v. Re- 
port, -p. IS,) flat, triangular (in that respect alone like TeUina 
Bumeti) and with very distant ribs outside. These ribs are 
generally sharp, but sometimes rather flat and rounded. The 
anterior dorsal margin is concave in young specimens. The 
surface of the shell appears imder the glass, covered with fine 
radiating strise ; but under the microscope these lines are 
found to be simply the divisions between rows of parallel 
oblong dots, which most resemble the strung figs of commerce, 
and are laid in rows, side by side, over the surface of the shell. 
These show through in very young specimens, and present a 
most beautiful appearance. Inside, one valve has a long 
anterior lateral tooth, a short distant posterior one, and 3 nai-- 
row divergent cardinal teeth, of which the middle one lies 
between two broad pits, and the anterior joins on to the lateral. 
The other valve displays a long posterior, and small distant 
anterior lateral ; with 3 cardinals, of which one is the beginning 
of the posterior lateral, the middle rises between two pits, and 
the anterior is marginal, nearly obsolete. Muscular and pallial 
marks distant from margin. Tlie largest valve measures 
long. -16, lat. 'IS, alt. '05. 

iZf/6.— Panama ; not common ; C. B. Adams.—Maz&ildja ; off 
Chama; and Spondylus, very rare ; L'pool Col. 
Tablet 414 contains 4 valves, of different ages, and a fresh 

fragment to shew the 'strung-fig' structui'e. 

117. GouLDiA vaeians, n. a. 

G. t. minima, subtrigond, siibceqiiilaterali, forma plus minusve 
angulato-rotundatd, plus minusve elongatd ; alhidd,plus mimisve 
fusco maculatd ; suMrevi, striis incrementi, sive costis concen- 
tricis paucis sen numerosis ; superjicie lineis granulosis radi- 
antihus creherr'mnis ccBlatd ; nmhonibus subspiralibus, haud 
conspicuis; margine simplici, appresso ; dentibus lateralibvs 



84 MAZATLAN BIVALVES 

alterA valvd postico, altera antico magnis, longis ; cardinalihus 
3-3, quarum medius altera valvd minimus, altera maximus ; im- 
pressionibus muscularibus suhroticndatis, lined palUi amargine 
distantiore. 

Four or five well characterized species miglit easily be de- 
scribed from extreme forms of tkis variable little sbell. Lite 
one of the Crag fossil Astartidfe, it has concentric ribs either 
near the umbo, aU over the shell, or not at all. Sometmies m 
forming lines of gi-owth, it leaves a sharp projectmg ridge. 
Sometunes it is of a somewhat regular Venus shape (especiaUy 
wheu young) ; sometimes it is narrowed ai\d unusually pro- 
longed. Even hi its most ribbed form, it diSers from G. 
pacTfica in being very much smaller, not so flat, with umbos 
more spiraUy projecting, and with the anterior dorsal margm 
less concave, as well as in having the ribs smaller, and closer. 
It has the general size and appearance of Astarte triangularis. 
The colour is generaUy whitish, with a large anterior brown 
stain. The teeth are on the plan of G. pacifica, but display 
specific difi'erences in their comparative size. The surface 
under a high power displays tlie strung-fig pattern, but on a 
very much finer scale than in G. pacifica. Underneath the^outer 
layer, the sheU is somewhat gram dose. About a score of pairs 
and more than 200 single valves were found on the large shells. 
It was not noticed by C. B. Adams at Panama, but it probably 
finds its way as far Soiith, as I found it on specimens of Mure.K 
regius said to come from that place. 
Tlie smallest specimen measm-cs long. "03, lat. '035, alt. 'OlS. 
The largest „ „ „ '09, „ 'OS, „ 'Od. 

JI«6.— Mazatlan ; common hi shell wasliings ; L'pool Col. 

Tablet 415 contains 1 pair and 12 valves ribbed.— 116, 4 valves 
ribbed near the imibos.— 417, valves, nearly smooth.— 418, o 
valves regvdarly rounded.— 419, 5 valves elongated. 

Gentts CAEDITA, Brug. 

118. Cardita Califoknica, Pes/i. 

Pror. Zool. Soc. 1852, p. 100. ,^ , ,o.-t ioo i 

? = Cardita affinis, ^Icnke in Zeit. f. Mai. 1847, p. 188; et 

Gould ms. : non Sow. 

As this is the northern form representing the more tropical 
C. a (finis (Sow. Free. Zool. Sor. 1832, p. 195 ; V. also C.B.Ad. 
Pa.i. Shells; p. 264) it is probaldy the shell quoted as C. alimis 



MAZATLAN BIVALVES 85 

by Menke in Ms list of Melchers' Mazatlan shells, and by 
Gould as collected by Lieut. Green at Guaymas. I have C. 
affinis from S. W. Mexico ; but all, even tlie most minute, 
specimens from the Mazatlan collection belong to this species. 
C. CaHfornica differs from C. affinis (as far as my few speci- 
mens enable me to judge) in being rather less transverse, less 
mcuryed at the anterior ventral part, less narrow and projecting 
anteriorly, with the ribs rounder, larger, and covered with 
very large scaly protuberances at the posterior end. The 
colour also is much redder, and the epidermis lies in much 
finer concentric lines. 

C. Californica begins life in an irregular way without ribs, 
as a tmy white creature with concentric strife. The ribs howl 
ever on appearing soon become very large and well armed. 
The creature then looks like a tiny Tridacna, with extremely 
projecting umbos, subtrigonal, and nearly equilateral. At this 
time there is a large, distant, anterior lateral tooth. (There 
seems a general tendency among bivalves, in their earliest 
stage to an abnormal development of the anterior portion 
f Is the foot then more active than the siphons. Gradually the 
posterior part grows, the colour appears, and the anterior 
tooth draws nearer (proportlonaUy) to the hinge. There are 
generally one or two fewer ribs developed in the young than in 
the adult. The smallest specimen is -03 across ; the largest 
measures lojig. '78, laL 1-38, alt. "5. 

-ffrt/j.— Gulf of California, Mus. Cuming.— Mazatlan ; extremely 
rare adult, rare jim., nestling in crevices of Chama;, Spondyli 
Ostre* andPerna; i'l^ooZ Co^.—? Guaymas, Z/e«i. Green. 
Tablet 420 contains 3 minute valves and 2 pairs jun —421 a 

young specimen in situ on the back of a Perna, on which is the 

lower valve of Discina Cumingii, attached.— 422, an adult 

specimen. 

Genus VENEEICAEDIA, Lam. 

119. ? Venekicardia , sp. ind. 

Tal^Ict 423 contains a minute valve, whose characters are all 
those of Cardium except the hinge. This however presents a 
tnangidar cardinal tooth, with pits for the 2 opposite ones, and 
an indistinct, closely approximate anterior lateral There is 
no trace of posterior tooth. The outside is ribbed almost 
exactly as in Cardium graniferum ; but instead of the inter- 
Nov. 1855. 



86 MAZATLAX BIVALVES 

stices being pitted, tlie wliole sliell is decussated by very* fine 
rather distant concentric ridges, passing over and between the 
ribs. The large ventral ribs are hollowed in the interior of 
the shell. Long. 'OS, lat. 'Ol, alt. '02. 

Sah. — Mazatlan ; one valve in Spondylus washings ; L'pool 
Col. 

GexNUS ? TRAPEZIUM, Megerle. 

Megerle von Miihlfeld, Entwurf Slc. p. 68, 1811 :—Phil. Saiid. 

Conch. 1). 350. 
libitina, Schum. 1817. 
Cypricardia, Lam. An. s. Vert. 1819. 

120. ? Trapezium — , sp. ind. 

Tablet 424 contains a puzzling little shell, too young to 
identify even generically. It is shaped like the adult, not the 
young of Cardita, but entirely without radiating ribs. SheU 
transparent, subrhombic, irregiJar, anteriorl.y tnincate, umbos 
projecting, lateral ; valves smooth, with a few regidar distant 
concentric epidermal ridges ; inside with a very stout projecting 
cardinal tooth, fitting between two small ones in the opposite 
valve, and a posterior lateral tooth iu each. Ligament external : 
no trace of pallial sinus. Long. '02, lat. '04, alt. '03. 
Llah. — Mazatlan ; 1 pair, iu shell washings ; L'pool Col.* 

Family CHA^OD.^. 

This abcn-ant family is placed by Lam. and Woodw. between 
Unio and Tridacua ; by D'Orb. between Sixmdylus and Ostrea ; 
by Gray between Saxicava and Cardita : by Phil, between 
Cardiiuu and Lucina. In its adherent mode of life and irregular 
growth it resembles Ostrea ; wliile its two largo adductors and 
its si])hons remove it far away. Both animal and shell have 
relations with Isocardia (Glossidse, G-ray) which was, not so 
imuaturally as might appear at first sight, associated with it 
by Liunanis. 

• Of the two species of Gouldia in the Cumingian Collection, G. cerina, 
C. B. Ad. is conffenerio with tlie so called ' Circe ' minima, not with the G. Pacifica 
of the same author. Congeneric with the latter species and with G. varians are 
Crassatella Martinicensis, D'Orb., intermediate in form between the two Mazat- 
lan species, and Crassatella Guadaloupensis, D'Orb. the exact analogue of G. 
Pacilica. For which proup tlie generic name is to be retained, those who havff 
aeoQ the diagnosiii must decide. 



MAZATLAN BIVALVES 87 

Genfs CHAMA, (Fliny,) Linn. 
121. Chama frondosa, Brod. var. Mesicana. 

Cliama frondosa, var. h. Brod. Proc. Zool. Soc. 1834, p. 149. — 

Zool. Soc. Trans, vol. i. p. 302, pi. 38, f. 1, 2.—Bve. Conch. 

Ic. pi. 1, f. 1 h.—B. M. Cat. D'Orb. Moll. p. 87. no. 773. 
Compare Chama ecliinata, Brod. in Zool. Beech. Voy. p. 150, 

pi. 43. f. 9. — (? = C. echinata, pars, Brod. Proc. Zool. Soc. 

1834, p. 150:— Trans. Zool. Soc. 1835, p. 305, pi. 39, f. 57.— 

Rve. Conch. Ic. pi. 7, f. 35, jun.— C. B. Ad. Pan. Shells. 

p. 254, no. 407.) 

The Mazatlan Chama? were sent in tolerable numbers, and 
yet so commonly were their surfaces abraded that it is difEcult 
to discriminate the specific characters. The bulk of them are 
certainly C. frondosa, var. b, of Brod. and Rve., but were con- 
sidered a distinct species by Messrs. Cuming and Hanley. 
The tjTjical C. frondosa comes as far north as S. W. Mexico 
(P. P. C.J but Avas not found among the Mazatlan shells. I 
have not ventured however to describe it as a distinct species, 
till more is known of its power of local variation. 

Shell when extremely yoimg (as shewn by examining the 
umbos of the smallest valves found, under a half-inch achrom.) 
somewhat Venus-shaped, with concentric ridges, and a very 
finely shagreened surface, occasionally passing into very fine 
radiating sti-ise : interior as in adult. Many of the shells do 
not display this structure, but pass at once to the next stage, 
generally with vaidted spines, sometimes with irregtJar laminae. 
The inner margin at an early state is not crenidated : colour 
white, gradually developing a rich pink. In its adolescent 
condition, the interior is of a rich plum purple, irregidarly 
diffused, more or less stained with orange, especially at the 
teeth. The margin during this period often displays a most 
minute set of crenidations, within the line of meeting of the 
valves. All the specimens found in this state had lost their 
external characters. T\'Tien properly adidt, it is generally cover- 
ed with very irregular concentric layers rising into lamella?, 
rarely into spines, with a tendency to broader foliation in a pos- 
terior radiating area, ill defined. The interior crenations become 
then almost extinct. Colour outside brownish red, within 
white, more or less stained with the same. Shell attached 
sideways, generally by about a third of its surface, with very- 
large adductors, and hinge teeth which are more or less ser- 
rated ; white, bordered with pxirphsh brown. The ligament 



88 MAZATLAN BIVALVES 

ia strong, curling round the lunbos, like Isocardia, and becom- 
ing semi-internal beyond tlie hinge teeth. All the specimens 
are dextral. The laminfe are generally finely striated outside. 
These shells, like those of Spondylus, ofi"ered a safe retreat 
for boring and nestling bivalves and numerous minute Gas- 
teropods. The smallest valve measures "02 across. That with 
the largest animal, (shell somewhat thin,) long. 4'5, lat. 4'25. 
alt. 3"4. The heaviest shell measures externally (though part 
has been removed) long. 5 "7, lat. 5', alt. 5' ; internally (from 
ligament to margiu) long. 2'6, lat. 2'^, alt.2'2. This, with 
another smaller specimen attached, weighs 51b. ; and displays 
a very large and persistent spiral ligamental groove. 
^a&.— Gulf of Tehuantepec, Mexico; dredged up from sandy 

mud attached to Aviculse, 10 fm. ; Mus. Cuming. — Mazatlan ; 

not common; L'pool Sf Havre Coll.* 

Tablet 425 contains 3 valves, extremely young, exhibiting 
the shagreened svu-face at the umbos. — 426, 2 do. umbos finely 
striated. — 427, 1 do. umbo spiral, as in young Calyptra?adae. — 
428, 1 do. concentric foliations developed. — 429, 8 valves, a 
stage older, spiny processes developed, valves inside variously 
coloured, and surface rugose.— 430, 1 pair and 3 valves, a stage 
older, colour highly developed. 

Tablet 431 contains 1 pair young. — 432, a specimen with the 
spiral umbos so enormously developed, as to approach the fos- 
sU form Diceras. The umbo of the attached valve makes two 
loosely spiral whirls, the ligament rimniug up the suttu'e ; in 
length it nearly equals the breadth of the sheU, but being 
fiJled up with solid matter, would not display itself in the 
internal cast. 

Tablet 433 contains a i)air, young, purple and orange, (closely 
resembling the C. echinata, "very old," figured in Beechey's 
Voyage.) Margiu very finely, and teeth strongly crenate. 
Outside, with Vermctidpc, Lithophagi, &c.— 434, 2 valves at- 
tached to each other, pierced by Lithophagi, &c. The outer 
layer has become eroded, except where the Lithophagi have 
bored. 

Tablet 435 contains a diseased specimen, purple, attacked by 
Lithophagi, even to the very centre of the teeth. 

Tablet 430 contains a finely grown adidt specimen, attached 
to Pinna, with Vermetida- &c.— 137, the sp. with the largest 
animal. — 138, the group with the largest shells. 

• A speoimeu received from Dr. Gould of this species (without reference) is 
probably thf "C. Paeifioa" of his list, "Guajinas, Lieut. Green." It may 
however be the C. Buddiana, C. B. Ail. : t. iufra. 



MAZATLAN BIVALVES Hi) 

121, b. ChaMA ? FEONDOSA : var. FOHNICATA. 

C. Ifrondosa, t. costis nwmerosis irregularihus radiantibus, 
squamis fornicatis crehris indiotis ; hue et iUucfrondosd ; intus 
alba, ad marginem rubro-purpurea ; margine crenulato ; den- 
tibus ad apicem valde serratis ; epidermide cinerea ; per totum 
lafus affi-xd. 

Compare C. Buddiana, C. B. Ad. Pan. Shells, p. 253, no. 405 ; 

Panama, rare ; G-uaymas, Lieut. Green. 

A few specimens diifered from the rest of the Mazatlan 
Chamae in having the surface (especially anteriorly) covered 
with radiating costsB, rising into scales which are often semi- 
tubular. The colour never disijlays the rich i)urple and orange 
of C. frond. Mexicana, being white bordered with puce. The 
attachment is more completely lateral ; margins more strongly 
crenate ; edge of hinge tooth sharply serrate. Shell covered 
with an ashy epidermis, sometimes olivaceous, not noticed 
even in young specimens of C. frond. Mexicana. These charac- 
ters might be sufficient to mark out a species, if constant : bixt 
as I find many of the adult specimens that cannot be referred 
with certainty to either form ; and as each of the characters 
(except that of the epidermis) is in both forms subject to vari- 
ation, their claim cannot be regarded as established. The 
shell seems to have relations both with C. Broderipii and C. 
Buddiana : on the other hand it sometimes displays posteriorly 
more of the characters of C. frondosa proper than does the 
ordinary form. The valves xmite so closely that a specimen 
(attached to Byssoarca) on being opened, two years after being 
brought to this country, was found full of the soft animal mat- 
ter, of course in a state of the most fetid decomposition. In 
the young state it is not to be distinguished from C. frond. 
Mexicana, and scarcely from C. spinosa. It is also of the 
same size and habit of growth. 
Sab. — Mazatlan ; very rare ; L'pool Col. 

Tablet 439 contains 2 pairs and a valve, very young. — 440, a 
pair young. — 411 a pair well formed, adhering to the inside of 
a very large valve. The latter is incrusted with Sponge, Ver- 
metida^, &c., and nestled beneath the umbo two specimens of 
Byssoarca gradata have found a home. 442, a sp. attached to 
living Byssoarca pacifica (v. supra). — 413, a large specimen, 
containing in the upper valve Petricola robusta in situ ; in the 
lower, which had been attached to F rock by a large siu"face. 



90 MAZATLAN BIVAWVES 

a Gastrochfena tnincata iu its buiTOW, and a Petricola robusta 
Tvhicli, after penetrating to tlie Frock, Las flattened itself 
rather than bore into the harder substance. 

122. Chama spinosa, Brod. 
Pi'oc. Zoul. Soc. 1834, p. WO— Eve. Conch. Icon, in loc. 

Three small valves and one pair appear to belong to this 
species. The valves differ from the yonng of C. frond, fornicata, 
in having the entire surface crowded with semi-tubular spines ; 
and in the character of the margin, which is smooth and 
rounded within, outside with crowded scales one on another, 
like the base of Hipponyx tessellata. The tj^es and the pair 
do not display this structure, which appears very characteristic. 
Hinge teeth comparatively smaU ; muscular scars not very 
large ; colour wHte, with slight rosy tint at the umbos which 
are scarcely spiral. Long. I'l, laf. I'l, alt. '08. 
Hab.— Lord Hood's Island, Cumhig.—? Mazatlan ; extremely 

rare ; L'l^ool Col. 

Tablet 4M contains a valve. The paii- wiU be seen, attached 
to Ostrea, with Diseina, on tablet 20. 

123. Chama Pexogyea, Conr. 

One broken pair attached to a pebble, and a valve on Spondj^ 
lus calcifer iu the Liverpool Museum, differ from the rest ot 
the Mazatlan Chama> in the following particulars. bheU smis- 
tral • veutraUy produced ; surface roughened and laminated, 
not spinous; margin smooth, rounded off, slightly crcnate 
outside ; teeth long, small, colour reddish brown, without 
purple. Thev may belong to Ch. Panamensis, or even to Ch. 
corrugata, but seem best to accord with this species. Long. 1 o, 
lat.Vn, alt. 1-15. 
JZaJ.-Sta. Barbara, San Diego, &c. iYw^a/Z.-Mazatlan ; ex- 

tremely rare ; L'pool Col. 

Tablet 415 contains the specimen on pebble. 

Family C/\JlDIADJi;. 

Genus CAEDIUM, Linn. 

Only two species of this abundant genus were sent in any 

Quantity ; the shell washings however proved that many more 

must exist in the neighbourhood ; 5 species bemg found sul- 



MAZATLAN BIVALVES 91 

fieiently perfect to describe with tolerable accuracy ; and 
fragments of 5 others j)resentuig characters by which they 
may be hereafter distinguished. 

124. Caedittm: (L^vicaedittm) elatum, Sow. 
Pro. Zool. Sac. 1833, p. 8L—Eve. Conch. Ic. sp. 41, pi. 8, f. 41. 

This most magnificent cockle is known at once by its large 
size, smooth surface and yellow colour. It has however very 
faint, nearly obsolete ribs, covering the body of the shell ; but 
even these are not to be seen on a large, distinctly marked, 
posterior aud a smaller anterior poi-tion. About the umbos 
there are no longitudinal ribs, but very faint concentric ridges 
of growth. The shell has a decided posterior gape : edges 
crenated mthin, except at the smooth pai'ts : posterior lateral 
tooth in one valve marginal. Epidermis thin, crossed with 
numerous very fine concentric ridges. 

If I have rightly affiliated the young shells, (but there is 
nothing intermediate between "11 and 2 '63,) in its eai-ly state 
it is somewhat spotted, and much more transverse. The little 
shells suit better the description of C. Elenense. The teeth 
vary greatly in size, and the shells in thickness. Some of the 
young shells under a low power, and aU under a high one, dis- 
l^lay a pustidose surface, which ?may be traced near the umbos 
of the smallest distinct specimen of C. elatum. The smallest 
minute valve is '03 across ; the largest specimen measures 
loncj.'o-m, lat.4>-58, alt. 3-92. 
Sah. — GviajTuas, in sandy mud at low water, Mus. Cuming. — 

San Diego, Lieut. G-reen. — Mazatlan; not uncommon ; IS pool 

Sf Havre Col. 

Tablet 446 contains the smallest and largest distinct speci- 
mens. — 447, 3 perfect and 2 imperfect valves of C. ? elatum, jun. 



125. Caedium peoceeum, Soiv. 

Proc. Zool. Soc. 1833, p. 83.— Miill. Syn. Test. Viv. p. 216.— 
Soiv. Conch, m. no. 61, pi. 50, f. 23.—Rve. Conch. Syst. pi. 77, 
f. 23 -.—Conch. Ic. pi. 10, f. ^l.-Sanl. Descr. Cat. p. 140.— 
Menke, Zeit.f. Mai. 1847, p. 188, no. bl.—B. M. Cat. D'Orh. 
Moll. p. 74, no. 659.— C. B. Ad. Pan. Shells, p. 267, no. 433. 
This shell deserves favourable regard not only on account of 

the beauty of its form, but also because it has been quoted ia 



92 MAZATLAK BIVALVES 

no fewer than eleven books without a synonym ! The young 
shell however has not been so well treated, being, according 
to Jay and Eeeve, the C. laticostatuin of Soiv. It certainly 
suits exactly the description and measurements given m Proc. 
Zool. Soc. 1833, p. 85. Mr. Cuming however states that C. 
laticostatum is distinct and is the larger of the two ! The 
young C. procerum moreover is not to be distmguished trom 
the figure of the young C. Panamense in Zool. Beech. Toy. 
pi. 42, f. 7. which is described by Sow. Proc. Zool. Soc. 1833, 
p. 85, as only 1-5 in. long. The specunens in the Cumingian 
Collection however are extremely large. The Mazatlan shells 
are manifestly of one species. It begins life nearly orbicular. 
A young sheU, 'o in. long, displays 7 close posterior ribs, 
sharply serrated at the margin, and with rows of tubercles on 
their summits. The 10 ventral ribs are then subtriaugular, 
rather sharp, minutely dotted at the top, and with the sides 
and very narrow interstitial spaces finely decussated by con- 
centric ridges which tray el up and down oyer them. Ihe 
sk anterior ribs are very much flattened, and faintly decus- 
sated by the concentric lines.— Gradually both tubercles and 
concentric ridges disappear, at an earher or later period ; the 
ribs then become flattened, and at last on the anterior part 
nearly pass away. The shell assumes a longer or broader 
form,' with every gradation between. The number of ribs varies 
from'21— 25, and does not depend on the shape. The colour 
is whitish, yariously spotted with reddish brown ; inside near 
the posterior marcriu, (which is very ringent,) of a rich brown- 
ish pui^le. The ends of the ribs project beyond the margm of 
the shell at the posterior yentral part, and beautifully inter- 
lock. The side teeth are in a very slight curye from the car- 
dinal. Epidermis thin, with very closely concentric ridges. 
A broad specimen measures lo)iff. 2 '5, lat. 2 "2, alt. 2 "04. 
The largest,, „ 3-07, „ 2-5, ,,2-22. 

Sah.—Re&l Llejos, in coarse sand 4-6 fm. Ciii)ii>ig.—Pa.yta,, 
D' Or J/5r«^.— Panama, rare, C. B. Adams.— S. W. Mexico, 
P, P. C. — Mazatlan, Melckei-s. — Mnzatliin: common; 
L'pool Sf Havre Coll. 
Tablet 418 contains a minute imperfect yalve.—44S, broad 

yariety, 5 pairs and a valye. young.— 450. do. 3 sp. adult.— 

451, 4 sp. young, elongated form.— 452, 3 do. adult.— 453, a 

curiously deformed valve. 



MAZATLAN BIVALVES 93 

126. Caedium ? SEXTicosTJM, Sow. 

Proc. Zool. Soc. 1833, p. SL—M\lll. Syn. Test. Viv. p. 218.— 
Sow. Conch. III. no. 43, pi. 47, f. lO.—Rve. Conch. Si/st. pi. 74, 
f. 10:— Conch. Ic. Ind. Card. & Errata.— ^rtwZ. Descr. Cat. 
p. 137.— 5. M. Cat. D'Orh. Moll. p. 74, no. 658.-0. B. Ad. 
Pan. Shells, p. 268, no. 434. 
= Cardimn rastrum, Rve. Conch. Ic. pi. 16, f. 82.* 
? = Cardium muricatum, Menke in Zeit.f. Mai. 1847, p 188 
no. 50. 

Tablet 454 contains a nearly perfect minute valve and 6 frag- 
ments of larger shells, wliich probably belong to tbis species. 
Tlie ribs are extremely close, about 40, and bearing traces of 
grains wbick are strongest on tke anterior side. Tbe smallest 
fragment has a fine line running down the interstices, which is 
probably an accidental variety, as I have a specimen of C. 
echiuatum displaying the same structure. C. muricatum is 
the West Indian analogue. 

Halj.—St. Elena, in sandy mud, 6-12 fm. Cuminc/.— Ecuador ; 
St. Elena, D' Orbigni/.—Tahoga ; very rare ; C. B. Adams. — 
? Mazatlan ; extremely rare, in shell washings ; L'pool Col. 

127. Caedium s/j. ind. (a.) 

_ G. t. ?jun. minima, orhiculari, costis circiter xl. approxima- 
tts, hand extantihus, granifetns ; superficie tot a minutis- 
sime quasi arenatd, dentibus lateraltbus hand magnis. 

Two valves and a fragment only were found of this shell, 
differing from C. punctulatum, Brod. Sf Sow.. Zool. Joiini. 
vol. iv. p. 366, in the characters above named. The entire 
surface appears as though dusted over with grains of sand. 
It appears to be a young shell : if the adult, when found, have 
the same characters, it may take the name of C. arenatum. 
Long. -08, lat. "08, alt. '06. 

iZirri. —Mazatlan ; from Spondylus washings ; extremelj- rare ; 
L'pool Col. 

Tablet 455 contains a nearly perfect valve. 

• "Mr. ReeTe's relorenee to P. Z. S. 1811 for Sowerby's description is evidently 
a misprint for 1833 ; and the reference to the same work, 1845, for C rastrum 
seems erroneous Mr Uaiiley's reference to Eeeve Conch. Syst. pi. 84 is also a 
misprint for 74." C. B. Adam», he. cit. 



94 MAZATLAN BIVALVES 

128. Caemum , sp. ind. (l.) 

Tablet 456 contains a fragment of a slieU of moderate size 
wluch may possibly be C. triangiilatumSo^^. (St. Elena and 
Isle Plata, Cuming.) It bas very broad flat ribs, ^itli 2 rows 
of tubercles on eacb. Tbese communicate witb decussatmg 
lines in tbe interstices. 
_gV(6.— Mazatlau ; from sbell wasbings ; L'prjol Col. 

129. Caedium sjp. ind. (c.) 

Tablet 457 contains a fragment of a moderate sized Cardium 
baving relationsbip witb C. pseudofossHe, Eve. (Bchring s Sir.J 
It is of a dead wbite, witb very close, stovit, nnmeroxis, rounded 
ribs, barely nodulous, 
^ai.— Mazatlan ; from sbeU wasbings ; L'2^ooI Col. 

130. Caedium sp- ind. (d.) 

Tablet 458 contains a fragment of a tl^m wbite sbeU witb 
perfectly triangular, ratber distant ribs, witb flat sides. Tbe 
interstices are smootb, bounded by clearly marted bnes. 
jj-flj _Mazatlan : from sbell wasbings ; L'jpool. Col. 

131. Caedium , sp. ind. (e.) 

Tablet 459 contains 2 fragments, sometbing like tbe last, but 
coloured, and witb tbe ribs rounded and sligbtly nodulous. 
j2V,^,._Mazatlan ; from sbell wasbings ; L'pool Col. 

132. Caedium — ^P- i»'^- (f-) 

Tablet 460 contains 2 minute fragments, witb very narrow 
smootb rounded ribs, very far apart. Interstices broad, smootb, 
bounded by distinct bnes. 
Bai.-Mazatlan ; from sbell wasbings ; Lpool Col. 

133. Caedium alabasteum, n. s. 

C t parvd, am, nitidd, subdiaphand, suba^qmlaterali, 
dongatd ; costis eirciter xviii., quarum qu a t a or l^^j'^jl^ 
meaner disiantcs, costellis utr dque suhtr igonu- 
latil^iccm versus granuhUis; Interstitns nunnt.ssme deem- 



MAZATLAN BIVALVES 9o 

satis ; parte anteriore punctis ovalihus impressis decussatd • 
dentibus lateralibiis approximatis. 

Tliis cliarmiug little creature lias a general resemblance to a 
minute C. costatiun ; but tbe large ventral costse are rather 
rounded, witb. a little one on eacb. side making tbem appear 
somewhat trigonal. The anterior portion is strongly indented 
witb oval pits. The appearances it presents under tbe micros- 
cope vary greatly according to tbe direction of tbe ligbt. Tbe 
young shells have fewer ribs near the hinge, where the teeth 
are not fully developed ; are rather less equilateral ; and are 
granulose on tbe ribs. Long. '12, lat. "11, alt. "08. 

Mah. — Mazatlan ; in Chama and Spondylus washings ; ex- 
tremely rare. 

Tablet 461 contams 2 valves, the largest and tbe smallest. 



134 Cardittm g-eaniferxjm, Brod. Sf Sow. 

Zool. Joiirn. vol. iv. p. 367. — Sow. Conch. III. no. 38, pi. 49, 
f. 17.— Eve. Conch. St/st. pi. 76, f. 17 -.—Conch. Ic. pi. 8, 43.— 
Hani. Descr. Cat. p. 137.-0. B. Ad. Pan. Shells, p. 266, 
no. 430.—^. M. Cat. UOrh. Moll. p. 73, no. 652. 
Tbe smallest valve found, which only measures '03 across, 
scarcely shews a trace of teeth. Tbe young shells are nearly 
rectangular at the posterior end ; when older, they are obtuse 
angled. The interstices between the ribs are decussated by a 
series of rectangular impressed pits laid transversely. The 
largest specimen found measures only long. '12, lat. "12, alt. 'Oe. 
Hah.— Dug from a depth of about 6 inches in the mud of the 
Estaro de Mazatlan ; Lieut. Belcher.— G}Af of ]N"icoyia and 
Xipixapi; Cuming, D'Orhigny. — Panama, extremely rare, 
C. B. Adams. — Mazatlan ; a very few young valves and frag- 
ments in the washings of Chama; and Spondyli ; L'pool Col. 

Tablet 462 contains the largest (imperfect) valve, and two 
small ones. 



135. PCardium , sp. ind. (g.) 

? C. t. juniore suhorbiculari, alhidd, valde inceqnilaterali ; 
margine dorsali postice recto, antice concavo ; costis circiter xviii. 
validis, rotundatis, approximatis, tiiherciiUs latis armatis ; 
dentibics elongatis, lateralibus distantibus. 



96 MAZATLAN BIVALVES 

A puzzKng little shell, of whieli were found only one minute 
valve and a larger fragment. Eemarkable for the very stout 
ribs, -well armed with coarse tubercles, and for the Lucma-like 
shape of the dorsal margin. It has about 10 ventral nbs, but 
the species probably has more when adult. If then of the 
same shape, it may take the name of C. lucinoides. Long. "Oi, 
lat. "04, alt. '03. 
Sab.— Mazatlan ; extremely rare ; in sheU washings ; L'pool 

Col. 

Tablet 463 contains the valve. 

Family LUCINID^. 
Genus LUCINA, JBrug. 

This genus, so abimdant in the Atlantic, and especially in 
the West Indies, appears very rare on the Pacific coast of 
America. C. B. Adams records only one species from Panama, 
and this does not belong to the genus ; D'Orbigny none from 
the West coast of S. America. Eeeve describes 3 species 
(fibula, eburnea, and calculus) discovered by Mr. Cimiing. be- 
sides L. punctata and muricata, previously known ; and L. 
annulata from ? California. Dr. Gould has another, from 
^.capulco. Only one small species was at aU common in the 
Mazatlan collection ; though there is evidence of the existence 
of a tolerable number of others. Some of the Luciufe are not 
at aU constant in their characters ; the same species sometimes 
displaying, or not, radiating and concentric ribs, and having 
its margins smooth or crenated. Not a few of the species 
appear to have a very ■v\-ide distribution ; L. occidentalis. Eve. 
(olim pecten) being quoted from the West Indies and Ld. 
Hood's Island, and L. borealis from the British Seas and the 
Philippines. Many of the Mazatlan species were found en- 
tangled in the byssal mass of the large Modiola\ 

136. LxJciNA (Codakia) tigeeina, Lin. 

Venus tigerina, Linn. Si/st. Nat. p. 1133-4.— i?o;-» Jifus. p. 70.— 
C/iemn. vii. p. 6, t. 37, f. SdO-l.—Schroeter Einl. ih. p. 136.— 
Mont. Test. Br. p. 119, t. 4, f. 1.— Dorset Cat. p. 35, t. 1. 
f. U.—Dillw. Cat. vol. i. p. 191. no. 76 i—^'c. 

Cytherea tigerina, Lam. An. s. Vert. ed. 2, vol. 6, p. 318.— 
Turt. Dyth. Br. p. 161, pi. 10, f. \2.—Flem. Br. An. p. 4i5. 



SIAZATLAN BIVALVES 97 

Lucina tigerina, Desk. Erie. Meth. vers. t. 2, p. 384, no. 37. — 
Sow. Gen. hue— Desk, in Lam. loc. cit. p. 318, (2). — Forbes 
Sf Sanl. Br. Moll. vol. ii. p. QA.—B. M. Cat. Cuba Moll. 
p. 41, no. 499. 

Tkis abundant W. Indian sliell will not be received by many 
as belonging to the Pacific fauna. I can only say that I found 
the specimen, papered and numbered in the Dosiaia box, per- 
fectly fresh, and bearing every mark of having been taken 
alive. As further evidence of its lingering existence in these 
seas, I record fiading a fresh valve among a collection from the 
S. W. Mexican coast. The shells are both exactly like the 
normal W. Indian type, and differ essentially from its Panama 
analogue, L. punctata, Linn. Long. 1'48, lat. 1'6, alt. '58. 
JIab. — West Indies, passim. (Jamaica, Lister. — Barbadoes, 
P. P. C. — St. Domingo, D'Avila. — Cuba, Sagra.) — Amboyna, 
Eumphius. — Nicobar Is., Chemnitz. — [Britain, Montague, 
&c. ? imported.] — S. W. Mexico, 1 fresh valve, P. P. C. — 
Mazatlan ; 1 fresh specimen ; L'pool Col. 
Tablet 464 contains the specimen. 

137. Lucina ?? punctata, Linn. 

Venus punctata, Linn. Sijst. Nat. p. 1134. — Chemn. Conch. 
Cab. vii. p. 1.5, pi. 37, f. 397-8. 

Cytherea punctata, Lam. An. s. Vert. vol. vi. p. 319, no. 54. 

Lucina punctata. Desk. Diet. Class. cVhist. not. t. 9. — Sow. Gen. 
Luc. f. 1. — P.iie. Conch. Ic. pi. 1, f. 2. 
Tablet 46-5 contains two minute valves, "03 across, which are 

evidently the young of a somewhat large species, perhaps this. 

One of them has close radiating ribs from the commencement ; 

the other is smooth, with striae of growth ; till, near the margin, 

after a sharp concentric ridge, it suddenly betakes itself to 

making longitudinal ribs. The teeth somewhat resemble the 

young of Dione, with the extreme ones very large in proportion. 

Hah. — "L'Ocean des Grandes Indes," Lamarck. — Panama, on 
the sands at low water, C timing. — ?? Mazatlan ; jun. extreme- 
ly rare, in sheU washings ; L'pool Col. 

138. Lucina Pannulata, Reeve, 
Reeve, Conch. Ic. pi. 4, f. 17. 

Tablet 406 contains a fragment with rounded concentric ribs, 
and very fine concentric striae traveling over bjtii ribs and 
Nov. 1855. k 



98 MAZATLAN BIVALVES 

interstices, wMch may belong to this species. 
Sab. — PMazatlan : in shell washings ; L'pool Col. 

139. LuciNA Pmueicata, Chemn. 

Tellina muricata, Chemn. Conch. Cab. xi. pi. 199, f. 1945-6. 
Lucina muricata, Rve. Conch. Ic. pi. 8, f. 46. 

Tablet 467 contains a fragment, with extremely fine, close, 
radiating ribs, rising in concentric lines into sharp scales. 
Hah. — PMazatlau ; in shell washings ; L'pool CoL 

140. Lfcina excavata, n. s. 

L. t. alba, tenui, complanata ; suborbiculari ; striis concentricis 
exillimis ; postice angulata, umbonibiis incurvatis ; lunula 
parva, alte excavata; dent. card, et lat. hand magnis ; 
impressionibits muscularibus postica ovall, anticd valde elonga- 
td ; margine integro. 

Distinguished by the very small, most deeply cut lunule, 
bounded on one side by the cardinal, oh the other by the 
anterior lateral tooth. A larger lunular portion is marked out 
by a line, and the posterior margin is slightly bi-angidated. 
Smallest valve "03 across. Largest, long. "38, lat. '41, alt. "12. 
Hub. — Mazatlan ; 2 valves and fragments among shell wash- 
ings ; L'pool Col. 

Tablet 468 contains the two valves, and a fragment to shew 
the external surface. 

141. Lttcina , sp. ind. 

Tablet 469 contains a fragment, smooth outside, with the 
umbo slightly ])rojccting; inside with a stout rotmd cardinal 
tooth, and deeply impressed internal ligament pit. I have a 
very similar species from Port Jackson. 
Hab. — Mazatlan : in shell washings ; I! pool Col. 

142. Lucina pectinata, n. s. 

L. t. albidd, suborbiculari, planatd, marginibus rotundutis ; 
costis radlantibm appres.vs, hue et illuc bifidis,juniore circiter x. 
adultd circiter xxx. ; postice non diraricatis ; lineis freqiventis- 
simis concentricis a costis undatis ; lunuld parvd ; dent. card, 
et lat. hand magnis ; ligamento subinterno ; impressionibus 
muscularibus posticd subrotundatd, anticd valde clongatd. 



MAZATLAN BIVALVES 99 

Differs from L. cancellaris in being much larger and flatter, 
with the teeth and lunule smaller in proportion. There is no 
posterior angle or flattening. The radiating ribs divide as in 
L. cancellaris, but the concentric ridges, instead of being 
sharp and standing so as to leave deep j)its between, are very 
close and fine, running up and down across the ribs and inter- 
stices. It seems closely allied to L. fibula (St. Elena and 
Philippines), and to L. costata, D' Orb'tgny, (Brazils.) Long. "44. 
lat. -49, alt. -16. 
Sab. — Mazatlan ; one fresh valve and fragment, entangled in 

the byssus of Modiolae ; L'pool Col. 

Tablet 470 contains the valve. 

143. LUCINA CANCELLARIS, Th.il. 

Zeit.f. Mai. 1846, p. 21, no. 7. 

Shell, when extremely young, smooth at the umbo, then 
with stout concentric ridges, then with 8 or 10 very strong 
radiating rounded ribs crossing them. These branch out into 
other nan-ower ones, till there are about 26, strongly cancel- 
lated, and leaving deep pits between. "The form closely 
resembles L. commutata, Pldl., which is the real T. divaricata 
of Linnaeus. With L. pecten, squamosa and reticulata (Poli, 
not Lam.) it must not be confounded ; its strong rotundity, 
almost equilateral form, and the character of the sculpture at 
once distinguish them." (Phil. loc. cit.J Lunule small, deep : 
posterior ligamental portion flattened, separated by an indis- 
tinct keel. Interior margin deeply crenated ; muscular scars 
(anterior elongated, irregular) rather distant from margin ; 
lateral and cardinal teeth strong. The smallest specimen is '03 
across. The largest, long. "15, lat. '14, alt. "09. 
ffab. — Mazatlan, Philippi.— Do. : extremely rare ; L'pool Col. 

Tablet 471 contains the youngest valve and the largest pauv. 

144. LuciNA Mazatlakica, n. s. 

L. t. parvd, alba, suborbiculari, umbonihu.'s antice incui'vatis, 
lunula longa, margine postica obscure biangulato ; primum liris 
concentricis, aculis, plus minusve dintantibus ; postea radiis 
quoque rotundatis, creberrimis^ ad margijiem decurrentibus ; 
liris ad angulam posticam quibusdam obsoletis, reliquis extari' 
tibus ; area posticd subplanatd ; dentibus card, parvis, lat. sub" 
distantibus ; Ugamento ciirto, subexterno ; impressionibus mus' 
eularibus hand elongatis ; margine (haud semjger) crenato. 



100 MAZATIAK BIVALVES 

Though 200 valves were found, many of them fresh from the 
banquets of carnivorous Gasteropoda, there was only one pair. 
When young, nothing is seen but the concentric ridges j the 
shell is then elongated anteriorly, and scarcely to be distin- 
guished from the young of L. prolongata ; afterwards it assumes 
a regiilar, rounded form, with the posterior part flattened, and 
bearing fewer but more elevated ribs. The radiating ribs first 
appear at different ages, and are verj- close and little raised. 
The margin is often not crenated in the young shell. The 
smallest valve is only '03 across ; an unusually large one 
measures long. "15, lat. '16, alt. '09. 
Hob. — Mazatlan ; in shell washings, between the ribs of Cardia, 

in crevices of Chamaj and Spondyli, &c., not uncommon ; 

L'pool Col. 

Tablet 472 contains the pair, and 14 valves of different ages. 

Tablet 473 contains 3 valves, which m^ be an elongated 
variety of this species, or the young of L. prolongata. 

145. LUCINA PEOLONGATA, W. S. 

L. t. parva,Jlavida, soUda ; antice, maxim e prolonga- 
ta: marginibus rotundatis, lunula longa, umbonibus antice 
incurvatis ; liras concentricas rotuiidatas plus minusve mon- 
strante ; intus dent, crassioribiis, lat. subapproximatis ; impres- 
sionibus muscularibus regularibus, subovalibus ; margine interna 
seu planato seu crenulato : ligamento parvo, externo. 

Shell somewhat resembling L. calculus. Rve. (Conch. Ic. pi. 11, 
f. 68, taken in coarse sand, 10-13 fm., G-ulf of Nicoyia, Cuming,) 
which however is described as smooth, polished, shining white. 
This is of a yellowish cast ; and though the rounded ridges are 
often nearly obsolete, yet it is never polished. On one speci- 
men were 3 deeply cut concentric sulci. The young shell has 
its ribs sharper, when it resembles L. Mazatlanica. The pos- 
terior part is rounded off. Inside there is a glossy deposit over 
the mantle part, the margin being very finely rugose. The 
muscular scars in this species and the last are much more 
equal than in the typical forms. The smallest valve is "04 
across ; the largest measures long. '16, lat. "13, alt. '08. 
ZTaft.— Mazatlan ; from the crevices of Chamse and Spondyli, 

very rare ; L'pool Col. 

Tablet 474 contains a large and a small pair, and 5 valves 
differing in age and markings. One, having been bored by a 



MAZATLAK BIVALVES 101 

Gasteropod and then deserted, has made a coating over the 
hole inside. 



146. PLuciNA , sp. ind. 

Tablet 475 contains a fragment of a pinkish shell with verj 
smooth angular ribs. 
^a6.— Mazatlan ; in shell washings ; L'pool Col. 

147. Ltjcina Pebttenea, Reeve. 
Conch. Icon. Lucina, sp. 49, pi. 8, f. 49. 

Tablet 476 contains a young valve of exquisite beauty which 
may belong to this species, unless indeed it be a StrigiUa lenti- 
cula. It is of glossy white, and so transparent as to shew the 
muscular impressions outside, and the external markings within. 
Suborbicular, with umbo very projecting between two concave 
margins and nearly central. Surface covered with very crowd- 
ed concentric striae, which at the margin shew a tendency to 
commence divarication. It is '06 across. 
Hah. — St. Elena and Panama, in sandy mud, 11 fm. Cuming. — 

? Ma^atlan ; one valve in Spondylus washings ; L'pool Col. 

148. Lucina , sp. ind. 

Tablet 477 contains a fragment of a thin, globose species, 
with very numerous sharp concentric ridges ; interstices de- 
cussated by very fine radiating striae. 

Hah. — Mazatlan ; fragments of two specimens in shell wash- 
ings ; L'pool Col. 

Genus PFIMBEIA, Meg. 

Fimbria, Megerle v. Miihlfcld, 1811, Entwurf &lc. p. 52. 
Corbis, Cuv. 1817, Regne An. vol. iii. p. 147. 
Idothea, Schum. 1817, JEssai. 

149. ? FiMBEiA , jun., sp. ind. 

Tablet 478 contains one of two tiny valves which seem to 
belong to this genus, having the teeth of Cardium, with con- 



102 MAZATLAN BIA'ALVES 

centric ridges slightly decussated. They are evidently yonng, 
extremely thin, and shaped like the fossil F. lameilosa. 
Lotig. -06, lat. 'OS, alt. -04. 

Hob. — Mazatlan ; oflp Spondylus calcifer, 2 sp. ; L'pool Col. 

Genus DIPLODONTA, Bronn. 

Diplodonta, Bronn 1831, Italiens Tertiargeh. p. 9. 

Mysia, Gray, Proc. Zool. Sac. 1847, p. 195, (non Mysia Leach,) 

teste Phil, in Handb. der Conch. ^ Mai. p. 342. 
Glocomene, Leach (a secundd manuj Br. Moll. 313. 

For a full account of the remarkable peculiarities of the 
animal of D. rotimdata, v. Clark Moll. Test. Mar. Br. p. 82. 

150. Diplodonta semiaspeea, ? Phil. 

Quoted by Philippi, in Ahhild. Conch. Tellina, p. 25, under 

TeUina pisiformis, Aug. 1846. 
? = Lucina orbeUa ; Gould, Proc. Bost. Soc. N. H. Nov. 1851, 

vol. iv. p. 90 -.—Cal. Sf Mex. Shells, p. 22, pi. 15, f. 3. 
? = Lucina semireticulata, B. M. Cat. D'Orb. Moll. p. 72, 

no. 640 -.—Do. Cuba Moll. p. 41, no. 498. 
?=Lucina coelata, Rve. Conch. Lc. pi. 6, f. 27, a, b. 

A small colony was found in a burrow in Chama, old and 
young, most tightly wedged. They apparently hved on till 
they smothered each other. The shape of individuals varies 
extremelj\ Some are nearly globular, others (smaller) much 
flattened. Some are solid, some with a glossy shell like 
Kellia. In some the ligament was conspicuous outside ; in 
others entirely hidden. The oiitside is sometimes nearly 
smooth ; sometimes with concentric lines of growth, here and 
there granulose. The ligamental plate is generally more or 
less turned in ; the teeth rather divergent and strongly bifid. 
The muscular scars are rather long, especially the posterior 
one, serrated within, aud (with the paUial line) near the mar- 
gin ; but even these characters seem to vary in every specimen. 
The umbo in the very young shell is subcentral, with the liga- 
ment entirely external, and the hinge teeth prominent. The 
smallest specimen measures 'Oil across ; the largest, long. "41, 
lat. -42, alt. -28. 

After a very careful comparison of the types of L. caelata, L. 
orbeUa and D. semiaspera, I am unable to detect differences 
between them which do not exist between specimens of the 



HAZATLAN BIVALVES 103 

latter. L. caelata is larger, •with, tke rugose markings more 
coarsely grained ; ligament concealed. L. orbella is of the 
same size and shape, but rubbed smooth, and with the ligament 
prominent. D. undata is closely related, but differs in having 
an anterior lateral tooth in each valve, as well as in outline. 
Sab. — According to Philippi, loc. cit., this species and Tellina 
pisiformis are found both at Mazatlan and in the W. Indies. — 
St. Thomas', Merk. — Mazatlan ; very rare, nestling in bur- 
rows ; L'pool Col. — (D. orbella) San Diego, Lieut. Green. — 
Sta. Barbara, Col. Jeioett. — (D. semireticulata) Cuba, Sagra: — 
Brazils ; B-io de Janeiro ; Patagonia ; D'Orbigny. 
Tablet 479 contains 4 pairs and 2 valves, young and flatten- 
ed. — 480, 2 pairs adult. 

150. (b.) DiPLODOXTA ? SEMIASPEEA, var. DISCEEPANS. 

D. ? semiaspera t. tenui, leviot'i, impressione posticd sub- 
rotundatd ; dentibus elongatis, ligamento omnino externa. 

Tablet 481 contains a solitary specimen, which, had the other 
shells been at all constant in their characters, would have been 
considered a distinct species. As it is, it must await the 
examination of further specimens, especially as L. orbella, 
Gould, appears intermediate between this and the typical form. 
Long. -29, lat. '31, alt. -021. 

Sab. — Mazatlan ; 1 sp. in burrow from Chama ; L'pool Col. 

151. DiPLODOIirTA OBLIQUA, Phil. 
Zeit.f. Mai. 1846, p. 20, no. 6. 

This species is said by Philippi to differ from D. trigonula 
in being more obUque, with the umbos not so sharp, and the 
dorsal margin not so straight. The umbo is placed at one third 
of the entire breadth. Long. '12, lat. \7, alt. '06. 
Hab. — Mazatlan, Philippi. — Do.; one worn valve from the 

Chama washings ; L'pool Col. 

Tablet 482 contains the valve. 

Gent7s 



A group of very nearly allied species, described by Reeve 
and D'Orbigny as Lucina-, viz. Lucina Candeana, (Cuba,) L. 
cornea, (coarse sand, 10-13 fm., Gulf of Is'icoyia, Cuming,) L. 



104 MAZATLAN BIVALVES 

nitens, (Is. Muerte, 11 fm., sandy mud, Cuming,) L. tellinoides, 
(do. Cuming : Taboga, not common, C. B. Adam^,) and the 
following, are placed by Woodward under Diplodonta (Man. 
Moll. pt. 2, p. 298.) They dififer essentially in form and habit 
from the typical species of that remarkable genus, and have 
relations (except in the hinge teeth) with Cyrenoides : but 
vmtil the animal has been examined, it would be presumptuous 
to create a fresh one for their reception. 

152. ? Diplodonta seehicata. Reeve. 

Lucina serricata, Conch. Ic. pi. 9, f. 25. 
Cyrenoida serricata, P. P. C. Cat. Prov. 

Mr. Reeve teUs us that this shell diflFers from the others 
essentially in form ; but his descriptions and figures often 
oblige students to take many things on trust. It has much the 
appearance of a brackish water shell, having a glossy epidermis 
eroded near the beaks. The allied species are however strictly 
marine ; and even these (though very rarely) are pierced by 
Gasteropods. The shell is extremely thin, Cyrenoides-shaped, 
but with the teeth of Diplodonta. Muscular scars elongated, 
rather irregular. The form is generally elongated, but some- 
times nearly round ; beaks appressed ; ligament subiaternal. 

The largest specimen measures lojig. "87, lat. "81, alt. "36. 

A rounded „ „ „ -72, „ 73, „ '31. 

Sab. — Mazatlan ; not uncommon ; L'pool Col. 

Tablet 4S3 contains a minute pair, broken, measuring '07 
across and 2 minute opposite valves, '03 across, from the Spon- 
dylus washings, which probably belong to this species. If so, 
they establish its marine station. The youngest valves, by 
transmitted light, display a fine radiating fibrous structure. 

Tablet 484 contains 6 specimens, varying in age and shape. 

Family KELLIAD^. 

The little shells, either overlooked in the days of Lam. or 
included in the heterogeneous genera Erycina and Amphi- 
desma, are now found to be inliabited by animals greatly dif- 
fering from each other. The British members, which alone 
have been carefully studied malacologicaUy, are distributed 
by Clark (Moll. Test. Mar. Brit. pp. 88 et seq.) under the 
families Kelliad£e, Montacutidas, Tiirtoniada;, Arcadse & Ana- 



MAZATLAN BIVALVES 105 

tinidae. The genera also are by no means satisfactorily ascer- 
tained ; the same shell having been described by Forbes and 
Hanley as Kellia nitida and Leptou convexum ; v. Br. Moll. 
vol. iv., app. p. 255. As the animals of the Mazatlan species 
are entirely unknown, a systematic arrangement of them is 
not attempted ; and they are simply grouped under genera 
according to the preponderance of characters. 

Gen CIS KELLIA, Turt. 

Kellia, TuHon Conch. Dyth. Brit. 1822, p. 56. 
Erycina, Pai/r. non Lam. (sp.) 
Chjronia (Laperousii) Desk. Rev. Zool. 1839, p. 356. 
Bornia, sp., Philippi, Emtm. Moll. Sic. 1836, p. 13. 
Tell i my a, sp.. Brown, III. Conch. G-r. Br. 

153. Kellia suboebiculaeis, Mont. 
Mya suborbieularis, Mont. Test. Brit. pp. 39, 564, pi. 26, f. 6. 
Tellina suborbieularis, Turt. Conch. Diet. p. 179. 
Kellia suborbieularis, Turt. Dith. Brit. p. 56, pi. 11, f. 5, 6.— 

Alder, Cat. North. Sf Burh. Moll. p. m.— Forbes Sf Hani. 

Br. Moll. vol. ii. p. 87, pi. 18, f 9, 9ff, 96, pi. O, f. 4>.—Searles 

Wood, Crag. Moll. (Palfeont. Soc.) Part ii. p. 118, pi. 12, 

f. 8, a, b. Clark Moll. Test. Mar. Brit. p. 89. 
Petricola suborbieularis. Gray, Ann. Phil. 1825. 
Erycina suborbieularis. Reel. Rev. Zool. 1844. 
Tellimya suborbieularis, Broion, III. Conch. Gr. Br. ed. 2, 

p. 100, pi. 42, f. 14, 15. 
+ Tellimya tenuis. Brown, loc. cit. f. 12, 13. 
? + Tellimya lactea, Broion, loc. cit. f. 10, 11.— (Kellia 1.) B. M. 

Cat. Br. Moll. pt. 7, p. 83, no. ^.—Loven, I. M. 44, 310. 
Erycina Geoffroyii, Pai/r. Cors. 30, pi. 1, f. 3—5. 
Amphidesma physoides. Lam. fide Sow..* 
Bornia inflata, Phil. Moll. Sic. vol. i. p. 14, & vol. ii. p. 11. 

After often repeated and most careful examinations of many 
hundred specimens, comparing them ■« ith each other and with 
the very minute description in the Br. Moll, as well as with 
every Atlantic specimen that has been accessible, I am unable 
to give any specific characters by which the Mazatlan shells 

* A. physoides, Lam. Erycina ph. Defh. The description of this shell 
(An. I. Vert. ed. De»k. vi. 130, no. 16, y will fit any similar species. "A. t. orbi- 
cal»to-globosa, byalina, vesiculari. Hab. au port 'da roi George. Peron." 



106 MAZATLAN BIVALVES 

can be separated from tlie British, or the aberrant forms from 
each other. The general aspect of the shells from the two 
localities is sufficiently distinct ; the Pacific shell being gen- 
erally thinner and rather flatter ; but the specimens from the 
Canaries brought by R. M'Andrew, Esq. so remarkably coin- 
cide with those from Mazatlan that Prof. Forbes was unable 
to distinguish them. 

The same changes of form observable in the Atlantic shells 
obtain in the Pacific. Sometimes it is very broad, ^dth the 
ventral margin produced and flattened ; sometimes orbicular, 
with all the edges well rounded. Sometimes (like its fresh- 
water neighbour Cyclas cornea) it is considerably flattened, 
sometimes very much swollen. The umbos varj^ in the same 
manner ; sometimes being but slightly prominent, sometimes 
very tumid and projecting, occasionally capped like Cyclas 
calyculata. The texture also is by no means constant ; being 
sometimes hyaline and perfectly transparent, sometimes of a 
duU ashy colour, sometimes opaque white. One valve, agree- 
ing in other respects, displays a large honeycomb pattern, the 
cells beiag transparent on an opaque ground. Most imexpect- 
edly of all, differences are fovmd in the hinge. The small cardinal 
teeth are sometimes distinct and conical, sometimes they pass 
off" gradually into the laterals. These are sometimes long and 
slender, sometiaies short, strong, slightly truncate. Some- 
times the ligament pit is concealed ; sometimes ver^- conspicu- 
ous while the adjacent teeth are small. Often one or both of 
the cardinal teeth are absent (probably through accident,) and 
the laterals are scarcely perceptible ; at other times they are 
unduly prominent. The aspect of the shell is generally slightly 
iridescent, either smooth or with extremely faiut stria3 of 
growth, with a very thin rather glossy epidermis. Almost all 
the Mazatlan specimens were found nestling (not boring) in 
family groups, in holes and crevices of the large Chama^, 
Spondyli, &c. ; the finest and most characteristic individuals 
lurking among mixed animal and vegetable debris, in the bur- 
rows of dead Lithophagi, Petricola;, &c. Most of the specimens 
foiuid were very young, but displayed their characters accur- 
ately under the inch or half-inch achromatics. They were 
frequently found in the small txibes of worms where they could 
never arrive at maturity. If specimens had been taken from 
the large hollows of dead bivalves, their favourite haimt in 
this country, they would probably have been stronger and 
larger. As the species is known to have existed from the 



MAZATLAN BIVALVES 107 

period of the Coralline Crag, it is natural to suppose that it has 
now a wide distribution, though its station is such as generally 
to elude discovery. It would be premature to pronounce 
absolutely on its specific relations, before the animals have 
been examined, and other seas more thoroughly searched. The 
extreme forms are quite sufficiently marked to allow of specific 
distinction, just as Capt. Brown has described 3 species fi-om 
the British varieties ; but the knowii propensities of nesthng 
bivalves, and the presence of intermediate specimens with ever 
varying characters, do not justify this course. The smallest 
specimen is '02 across : the largest measures long. '24, lat. '26, 
alt. ■ 15. 

Hab. — British seas, Auct. — Mediterranean, PJdlippi. — Cana- 
ries, M' Andrew. — Mazatlan ; not imcommon in crevices of 
shells, generally young ; L'pool Sf Havre Coll.—\_A. species 
probably identical is from Peru ; Col. Cuming. — The Chironia 
Laperousii of Desh., from Monterey, Mr. Hartweg, is quite 
distinct.] — Fossil : British Coralline Crag ; Searles Wood. 

Tablet 485 contains 12 pairs, of various sizes. — 486, 10 pairs 
of valves, very young. — 487, 10 do, adolescent. — 488, 2 sp. which 
had lived inside a dead Sphaenia fragUis, which had lodged 
in the hole of a Lithophagus aristatus, which had bored in 
Murex regius. — 489, 4 sp. iu situ, in Spondylus calcifer, Patella 
Mexicana, and Trivia sauguinea. 

Tablet 490 contains 1 sp. much inflated. 

Tablet 491 contains a pair of valves, with short truncated 
teeth : [? var.] — 492, 2 pairs and a valve, orbicular. 

Tablet 493 contains 3 valves, Hgamental pit prominent : 
[? var.] 

Tablet 494 contains the valve with the honeycomb pattern. 



Genus LASEA, Leach. 

Lasea, Leaeh ms.—B. M. Cat. Br. Moll. pt. vii, p. 81 :— 
Phil. Hand. Conch, p. 315. — Lasaja, Broion, III. Conch. (Jr. 
Br. 1827.— Lesaja. Moll. 1843 Phil. 1845. 

Bornia sp., Phil. 1836. 

Cycladina, Cantraine, 1836, Bull. Ac. Sc. Bnix. 

Poronia, Pecltiz, 184:3, Bev. Zool. p. 166. 

Kellia pars, Forbes Sf Ilanl. Br. Moll. 1850. vol. ii. p. &'». 

Autonoe, Leach, (a secundd manuj Br. Moll. 289.' 



108 MAZATLAIjf BIVALVES 

154 Lasea Pettbea, Mbrd. 
Cardium rubnim, Ifont. Test. Brit. p. 83, pi. 27, f. 4. (non Rve.) 
Tellina rubra, Ttcrt. Conch. Diet. p. 168. 
KeUia rubra, Turt. Dith. Brit. pp. 57, 258, pi. 11, f. 7, 8.— 

Forbes Sf Sanl. Br. 3loll. vol. ii. p. 94, pi. 36, f. 5-7 : (animal) 

pi. O, f. 'i.-~ Clark 3Ion. Test. Mar. Br. p. 9i.—Searles Wood 

Crag Moll. pt. ii. p. 125, pi. 11. f. 10. 
Poronia rubra, Reel. Bev. Cuv. Zool. 1843, p. 175. 
Lassea rubra. Leach, ms. — Brown III. Conch. 1827, t. 20, f. 17-19. 
Lesffia rubra. Brown, op. cit. ed. 2, p. 93, pi. 36, f. 17, 18. 
Petricola rubra, Gray Ann. Phil. 1825. 
Lasea rubra, B. M. Cat. Br. 3Ioll. vii. p. 82.— Phil. Sand. 

Conch, p. 345. 
Bornia semilunum, Phil. Moll. Sic. vol. i. p. 14, pi. 1, f. 16, & 

vol. ii, p. 11. — Krauss Sudafr. Moll. p. 2. 
Erycina violacea, Scacchi, Cat. 6. 
Cycladiua Adansonii, Cantr. Bull. Acad. Bnix. 
Cyclas australis. Lam. An, s. Vert. ed. Desh. vi. 270, (teste 

G-ray.) 
? Ampbidesma nucleola. Lam. op. cit. vi. 270. 
Autonoe rubra, Leach, Br. Moll. 288, pi. 12, f. 5, 7. 
[For otber references, v. B. M. Cat. loc. cit]. 

Wbetber tbe little Mazatlan sbells (of wbich only one pair 
and a few valves were found,) are distinct from the typical 
Europsean species, must be left for future determination, when 
its distribution shall have been better ascertained. The teeth 
are smaller than in most British specimens, but it by no means 
differs from them so much as do the Mediterranean examples. 
The late, deeply regretted Prof. E. Forbes considered that 
they might be identical. He gives the species from the North 
and South Atlantic. Dunker quotes a similar shell from the 
Guinea coast, and Krausb the same from South Africa. I have 
it from Java, and Singapore (among Chamse). Dr. Gould gives 
it from Massachusetts, South of Cape Cod. Mr. Cuming found 
a similar shell in abundance at Valijai'aiso, on liigh exposed 
rocks, seldom washed by the sea, along with a little Littoriua, 
like L. neritea. An extremely similar species is K. miliaris, 
Desh. from Eagle Bay, Magellan. A species closely resem- 
bling it in shape but white, and with concentric ridges (which 
however, being irregidar, may be a local variety) is from the 
Bay of Mexillones, Desert of Atacamas, Bolivia, adhering to 
Balani in exposed situations, (Cuming). Lamarck's Cj^las 
australis is from the Isle of Timor, with a variety from K- 



MAZATLAN BIVALVES 109 

G-eorge's Port, N. Holland, (Peron). From its station in 
crevices at extreme liigh water mark, it has probably often 
escaped detection. It may hereafter be found to be one of the 
very few ubiquitous species. The Mazatlan specimens were of 
normal shape, '05 across. 

Hub. — Britain, Mediterranean, &c. : v. supra. — ? Mazatlan ; 
extremely rare, from Chama and Spoudylus ; L'2oool Col, 
Tablet 495 contains the pair (broken in opening) and 2 
opposite valves, probably belonging to each other. 



155. Lasea tkigonalis, n. s. 

L. t. plus mlnusve irigonalijConiplanata, concentrice striata, 
umhonibus acutis ; cardinc dentibiis minimis ; card. 1-2 conicis. 
rotundatis ; lal. longis, gracilibus, vix mGnstrantibus ; fossa 
Ugamenti magna, marginem attingente ; impress, muse, addvct. 
magnis, suhrotundaiis. 

Two specimens of this curious shell were found tightly 
wedged in the hole of a borer in a Spondylus valve. They are 
so different that they would be considered specifically distinct 
but for their position and general.liabit. One is very trigonal, 
Nucula-shaped, with a very projecting little conical tooth in 
one Valve fitting between two very small ones in the other. 
The smaller specimen is of much more regular shape, with the 
teeth scarcely discernible. Both specimens are flat, concen- 
trically striated, with a rough epidermis, and are rather pearly 
within. A minute pair and fragments were also found, the 
former measuring '03 across. 

The trigonal specimen measures long. "23, Int. '3, alt. -17. 
The smallest one „ „ '19, „ -ai; „ 11. 

Hah. — Mazatlan ; nestlmg in Spondylus, extremely rare ; 
L'pool Col. 

Tablet 496 contains the two large pairs and one snuili valve. 

156. ? Lasea oblong\, n. s. 

L. t. obovuli, transversa, incBquilatcrali, tumid/ore, antice 
producta; alba, epidermide cinered, horridiore, subpilosd in- 
dutd ; umbonibus prominentibus ; marginibus undiqne cxcurvis .- 
dent. card, una, minuto, conico, lat. g radii i mis ; fossa Una- 
menti parvd, appressd. 
Bee 1855. ; 



110 MAZATLAJf BIVALVES 

Compare Ckironia Laperousii, DesJi. in Wooihv. Man. Moll. 
pt. 2. p. 295, pi. 19, f. 11. 

One fine fresh, valve was found of this species, which is not 
unlike Bornia luticola, Val. m Bee. Ohs. ILumb. The latter 
however appears to have very irregular ridges of growth and 
stronger teeth. The shell is distinguished bv its transverse 
shape, rough, somewhat pilose epidermis, and minute teeth. 
It seems to partake of the characters of Lasea and Kellia. 
Long. -16, led. -2, alt. 1. 

Hah. — Mazatlan ;♦ 1 valve off Chama ; L'pool Col. 
Tablet 497 contains the specimen. 



GexNtjs LEPTON, Turf. 

Tartan, Conch. Dyth. Brit., 1822, p. 61. — The typical species 
of this genus are easUy dL*tiuguished by their flat, shagreened 
valves, and diverging, prominent teeth. They are ranked 
with Arcadpe by Clark, Moll. Test. Mar. Brit. p. 75 et seq. 
Dr. Gray constitutes for them a fresh family • while Philippi 
follows Forbes in locating them with Kelliada?, and Woodward 
unites the whole tribe to the Lucinidte. Much more must be 
learned of the animals of the foreign species before their true 
position can be ascertained. Some of the species can with 
diflSculty be separated from Kellia by the shell alone. 

157. Lepton Clementinum, n. s. 

L. t. papyraced, alhd, concentrice undulatd, punctulis mini- 
mis creherrimis covfertd ; ino'quilaferali, stihqiiadratd, urnhoni- 
btts niagnis, prominctitibus ; marginihus dorsalihus incurvatis ; 
dent. card, uiio, celato, fossa m ligamenti parvam, dtpressam 
adjiciente ; dent. lat. diiohus cnrtis, divergentibus. 

Although. I had the misfortune to damage the onl;v- valve 
foimd of this beautiful species, yet the characters are so well 
marked that it appears best to describe it. The shell is shaped 
like dementia, with a few stout, rather distant, concentric un- 
dulations : texture transparent, and exhibitiug a most minute 
cellular structure, very evident by transmitted light. Hinge 
\ ery small, with a tiny, sunken, ligament pit and a minute 
almost hidden cardinal tooth adjacent; and two very' short 
but distinct diverging laterab. The umbo is made verj- prom- 



MAZATLAN BIVALVES 111 

inent by the hollowing out of the sides. Lon^. "025, lot. "035, 
alt. 02. 

Hah. — Mazatlan ; 1 valve off Spondylus ; L'pool Col. 
Tablet 498 contains the specimen. 

158. Lepton Dion^um, n. s. 

L. t. papyraced, alba, .<subtrigonali ; Icevi, striulis incrementi 
minimis confertissimis : incequilaterali, marginibus dorsalihus 
suhrectis ; cardine dent. lat. duohus curtis, prominentibtcs.Jos- 
sam ligamenti haud parvam continentibus. 

In the only valve found of this species, there is no cardinal 
tooth. The shape nearly resembles some species of Dione. 
with the dorsal margins nearly straight, and at right angles. 
It is known at once from L. Clementinum by the absence of 
cellular markings and concentric undulations, the place of the 
latter being supplied by minute crowded striae of growth. 
Long. -01, lat. "06, alt. -"03. 
Sab. — Mazatlan ; 1 valve off Spondylus ; L'pool Col. 

Tablet 499 contains the si^ecimen. 

159. Leptox umboxatum, n. s.* 

L. t. sitbquadratd, suhinflata, cinered, opacd; siriis incrementi, 
item hue et illuc liris acutis concentricis ornatd ; umbonibus par- 
vis, valde prominentibus ; margine ventrali compresso ; cardine 
dent. lat. haud longis, excurvatis ; fossd ligamenti valde depres- 
sd ; impress, muse, subrotiindatis. 

Shell Kellia-shaped, but with a small extremely prominent 
umbo, and a flattened ventral edge. Surface of a dull ashy 
colour, with an extremely thin epidermis ; rather solid, and 
not displaying the shagreened pattern ; with the lateral teetli 
short, but not so much so as in the other species, somewhat 

• As so little is known of this genus, I append a description of a perfect and 
well marked valve at present in my collection. 

Leptox Placunoideum, n. s. — L. t. planata, quadrala, sithintsqiiilaterali, 
ventraliter incurva, papyracea, alba, haud punctata; lirii) concentricis acutis, ten- 
traliter undulutia, inferylitiiH striia exillimi,i concent rici» ; umbonibus parvis, sed 
a linea dorsali recta valde promi.ientibug ; fossa li(/a>nenti parva ; dent. lat. parcis, 
extantibus, divergentibus, in uinbonc gifig, ad maryinem domalem paululum excurpa- 
tie ; dent. card, altera in valta nnllo, altera '! : imp. muse, haud conspicuig. 

Hab. — West Indies. Shaped like L. squamosum, but distinguished at once by 
the prominent umbos, iiuurved ventral margin, sharp concentric ridges, and 
absence of the shagreen pattern.— io7y. -07, lat. -1, alt. -03. 



112 MAZATLAN BIVALVES 

excurved ; ligamental pit in tlie umbo. One minute valve. 
("02 across,) and one Padidtwere found. Long. "06, lot. '08, 
alt. -04. 

Hah. — Mazatlan ; 2 valves ofFSpondylus ; L'pool Col. 
Tablet 500 contains tlie lareer valve. 



Genus PYTHINA, Rinds. 

Voy. Sulph. 184i, p. 70. — Known by its very trigonal shape, 
often ventrally indented and divaricately sculptured. It 
must not be confounded willi Pjthia. &/*?/;«. 1817, = Scara- 
bus, Montf'. : nor with Pythia, Gray, 1821,= Conovulus 
myosotis, &c. 

= Kellia, pars, Phil. Hanclh. Conch, p. 344 : — Wbodic. Man. 
Moll. ii. 295. 

160. Pythina stjbl3:vis, ?i. ,<f. 

JP. t. minimd, alha, epidermide tenuissimd stramined indutd ; 
ralde incequilatetali, transversa, trigond, vmhonibus prominen- 
tibus, margine ventrali seu recto seu suhincitrvato ; Ictvi. seu 
striulis exillimis divaricate radiantibus ; deiitibus card, altera 
valvd ii. divergeniibus, qiiarum una major, altera nullis ; dent, 
lot. elongatis, exillimis. 

Two pairs and two valves of tliis shell were found, differing 
in outline and sculpture, but probably identical. The character 
(jf the hinso seems more related to Montacuta than to Xellia. 
The smallest valve is '025 across : the largest measures 
long. -05, lat. '08, alt. -025. 
Hab. — Mazatlan ; on Charaa and Spondylus, extremely rare ; 

L'pool Col. 

Tablet 501 contains the two pairs, one closed, the other 
opened. 



Genus MOJfTACUTA, Turt. 

Conch. Bithyr. Brit. p. 58. 1822. 

According to Clarl; 3foll. Test. Mar. Br. pp. 88, 94, the 
typical species of this genus belong to the Anatinidre. wliile 
the aberrant species remains to constitute a new familv. Of 



MAZATLAN BIVALVES 113 

the following species, only a few valves have been found. They 
are however describod provisionally, as so little is known of 
the ti'ibe. 

161. MONTACUTA ELLIPTICA, n.,S. 

M. t. ohovali, lilammculLl, alhd, inarr/i/iibits tmdique sa tis 
excurvatis ; concent rice tenidfssime striata; umhonihus promin- 
entihus ; valvd altera, fossa ligamentiim recipiente, dent. card. 
nuUo, lateralihus lonr/is, graciUbiis, ad marginem adhcBrentihtts ; 
valva altercc ... .? 

Only 2 valves (not opposite) and one minute pair which I 
have not dared to open, were foiind of this species. The shape 
is very regular, and the teeth very slender. The pair is less 
inajqudateral. but this is probably due to its youth, being only 
'03 across. Long. '1, lat. '13, alt. 'OJi. 

Sah. — IVIazatlan ; off Chama and Spondylus, cxtremelj^ rare ; 
Upool Col. 

Tablet 502 contains the pair and largest valve. 

162. ? MONTACUTA SUBQUADEATA, n. S. 

M. t. oliloyiga, suhquadratd, solidiore,Jlavescente seu cinered ; 
sulcis concentricis, creherrimis, rotundatis ; umbonihus appressis, 
lunuld excavatd ; valvd altera dent. card, ttno, inter fossas 
duas, dent. lat. longis, prominentihus ; valvd alterd dent. card, 
una, elongato, prope marginem, fossd und, latd ; dent. lat. sub- 
obsoletis. 

One iierfect and two broken valves frcrc found, which are 
probably conspeciiic. The genus is doubtful : the hinge in 
one valve resembles Gouldia, and the shell is too much worn 
to determine the position of the ligament. It appears as 
though tliere were two cardinal teeth interlocking, with the 
ligament occupying the second pit : but instead of the hinge 
area being interrupted, the pits arc on a raised plate, as in 
Mactra, &c. Outside it resembles in miniature some of the 
oval Oolitic Astartidrc. Long. "1, lat. '13, alt. '03. 

Hah. — Mazatlan ; off Chama;, extremely rare ; L'pool Col. 

Tablet 503 contains the large perfect valve, with the frag- 
ment that is supposed the opposite. 



11-1 MAZATLAN BIVALVES 

162. MoNTACUTA , sp. ind. 

Tablet 501 contains a fragment of a stout sliell, in many 
respects like ? M. subqnadrata ; but entirely destitute of car- 
dinal teeth. The limule is much incurved : indistinct ridges 
run from the prominent umbo to the anterior and posterior 
margins ; surface concentrically striated ; hinge margin inter- 
ruj)ted, with large sunken cartilage pit bounded by 2 marginal 
callosities, but no lateral teeth. The shell when perfect was 
Ijrobably larger than the last. 
Sab. — Mazatlan ; off Chama ; L'pool Col. 

Family CYCLADID^. 

GEsrs CYEENA, Lam. 
]64. Cyeena olivacea, >i. s. 

C t. compressd, suhtrigond, Icevi, vel stnis incre- 
menti haud impressis, epidermide olivacea indutd ; margine 
vetitraU exeurvato, piosticuvi versus i^l^riun que siniiato ; postico 
angulato, subrostrato ; latere dorsali antico dcclivo, vix alato ; 
■umbonibus satis prominentibus, ligamento elongaio ; epidermide 
umbones tegente, I a me II is par vis eorr ugat is pler- 
umquc indiitd, maxime angul am posticam versus ; intus pur- 
purea, maxime umbones et marginem versus ; dent. card, iii., 
qxiarum altera valvd antici duo, alterd postici duo, bifidi sunt ; 
lat. 2-2, 1-1, parvis, la>vibu^, extantibus, quorum antici pro- 
pinqui, postici remoti sunt ; sinu pallii parvo, triangulari, 
angustissimo. 
= C. Fontainei, Desk. ms. in B. M. ct Mus Cuming, et P. P. C. 

in Cat. Prov. -. non ]J'Orb.. ad fid. spec. tj-p. : nee P/iil. in 

Zeit.f. Mai. 1851, p. 70, no. 93. 

This shell has been freely distributed as C. Fontainei, 
D'Orb., on the authority of M. Deshayes, who having the 
original types to consult, was sixpposed to be correct. The 
true C. Fontainei, however, is a more regularly formed shell, 
vrith faint concentric ribs and a glossy epidermis, and appears 
identical with C. placens. Haul. 1811. The species which Philip- 
pi has described under the same name is distinct from either : 
it may prove to be the following. C. olivacea is known out- 
wardly by its flattened form, generally beaked posteriorly ; 



MAZATLAN BIVALVES 115 

and by the rich olive epidermis, covering the umbos, and rising 
into irregvdarlj' corrugated folds, which are very close on the 
posterior part. The interior disiilays a very dark piirple over 
the greater ijart of the surface. Anterior adductor very near 
the margin. The outhne varies considerably, but not so much 
as in the next species. 

The largest specimen measures long. 22, lat. 2*38, alt. 1'26. 

A transverse „ ,, „ 1-7, „ 2'05, „ 1'06. 

An inflated „ „ „ 1*62, „ 1*8, „ 1-16. 
Sah. — Mazatlan ; not common ; L'pool Col. 

Tablet 505 contains 3 specimens much produced ventraUj', 
slightly so posteriorly.— 506, 3 do. less produced.— 507, 3 do. 
very shghtly produced, normal shape. — 508, 2 do. margin 
regular, very transverse.— 509, 2 do. less transverse. — 510, 3 
do. very irregular outline. — 511, 1 do. orbicular, aberrant, 
approaching aberrant fonns of the next species. 

165. Cyeena Mexicana, Brod. and Sow. 

C. t. " C. ulivacea;" simulante, sed ventricosiori, forma maxime 
variante, suhorbiculari, nuhtrigond, sew elliptic a ; parte postica 
seu prolongata, sen sii,hcurinatd, seic rotundatd ; exttis albescente, 
umboiiihus plerumque mojcime erosis ; epidermidefusco-oUvaced, 
lamellis creberrimis, nan corrug atis , 2^lerumque detritis ; 
intics albd, marginibus plus minusve violaced ; dent. card, 
magis inmquaUbus, lat. magis extantibus ; sinio pallii minimo, 
marginibus pauliim divergentibus. 
Cyrcna varians, P. P. C. Cat. prov. 
Pars = C3Tena Mexicana, Zool. Journ. vol. iv. p. 364. — Hani. 

Bescr. Cat. p. 94.-5. M. Cat. Corbiculada, p. 260, no. 59. 
■Var. = Cyrena altilis, Gould, 3Iex. SfCal. Shells, p. 27, pi. 16, f. 5. 
.Jun. = CjTena fragilis, De.'ih. ms. in Mus. Cuming. 
? = C. Floridana, Conr. Proc. Ac. N. S. PJiil. iii. 18-16, p. 23, 

pi. 1, f. \.—B. M. Cat. Corb. p. 257, no. 49. 

The original tj^pe of this species "in Mr. Sowerby's collec- 
tion" appears to be lost, and the description is too meagre to 
separate it from its congeners: "C t. ellipticd, ventricosd, 
utrinque rotundatd, antice breviore ; dentibus parvis, obtusis." 
Nevertheless, as it is further stated to be "outside white, with 
an olivaceous epidermis ; inside whitish, varied with reddish 
violet ; " and as it came from Mazatlau, it is fair to conclude 



116 MAZATLAN BIVALVES 

that it is tlie same sliell. In. order, liovrever, to include the 
whole of the species, a new description is appended, which 1 
had drawn out under the name, C. variaus, which is certainly 
not inappropriate. A very extreme form, also found by Mr. 
Darbishire in the L'pool Col., has been named C. altilis by 
Dr. Grould, from specimens, one of which is marked "Mexico" 
hjMaj.Rich; another "PMazatlan" by CoZ. Je?(.Wf. Some 
of the young shells are ticketed C. fragilis in the Cumingian 
Collection ; but as the name does not appear either in the 
P. Z. S. nor in the Cat. Corh. it has probably been merged 
into another, perhaps C. Floridana. 

Although the general appearance of these shells is sufficiently 
distinct from C. olivacea, yet there are many points of resem- 
blance between individuals. This species however, is much more 
variable ; almost always more ventricose ; epidermis tliinner, 
more deciduous, of a du*ty bi'ownish olive, with the layers 
very close and thin, not corrugated. These layers are gener- 
ally abraded, as are the umbos. The anterior cardinal teeth 
are rather more elongated : the lateral teeth rather more 
elevated ; the pallial sinus is rather triangular, not so naiTow 
as it generally is in C. olivacea. The violet colour is also of a 
somewhat lilac tinge, and very rarely covers the whole shell. 
While the outside is anything'but attractive, the mside is often 
extremely rich and beautiful. The j'ouug shells (of which an 
abundance were S3nt, but very few of C. olivacea, jun.) vai'y 
quite as much as the adults. Of the most aberrant, suborbi- 
cular form, Mr. Darbishire possesses a fine swollen specimen, 
with the umbos not abraded, and greatly resembling (except 
in the eijidermis and the inequality of the teeth,) the speci- 
men, tablet 511, of the last species. A young suborbicular 
specimen measures long. '95. lai. 1'06, alt. '76. 

A voung transverse sp. ,, 1'13, ,, 1"5, ,, '81. 

The largest sp. „ 2-15, „ 2-52, „ 1-46. 

Mr. Darbishire's sp. „ 1-67, „ 1"74, „ 1'19. 

Hab. — Mazatlan ; not common ; L'pool Col. 

Tablet 512 contains 4 specimens, very'-regular outline, sub- 
orbicular. — 513, 4 do. slightly transverse. — 514, 4 do. a little 
more transverse. — 515, 5 do. very transverse. — 516, 4 do., the 
same, slightly swollen venti'ally. — 517, 4 do. rather more 
swollen. — 518, 5 do. loss transverse, normal state. — 519. 4 do. 
margin regular. — 520, 5 do. subtrigonal. — 521. 4 do. posterior 
part subangulated. — 522, 6 specimens shewing the interior. 



MAZATIiAN BIVALVES 117 



Family UNIONIDiE. 

Genus AJ^ODONTA, Cuv. 
Anodonta, Cuv. Tabl. Elem. 1798. — Anodon, Oken, 1815. 

166. Anodonta ciconia, Gould. 

Anodon oiconia, Gould Froc. Bost. Soc. Nai. Sist. vol. iv. 

p. 92, Nov. 1851 :— Ife.T. 4' Cal. Shells, p. 29. 
Anodon sinuata, Swains, (as of Lam. non A. sinuosa. An. s. 

Vert. vol. vi., p. 569, uo. 14.) Exot. Conch, p. 29, i)l. 16, edit. 

Sanl. 

Distinguished from A. anserina, (Brazil.) according to Gould, 
by being tliicter, more tumid on the posterior half, epidermis 
and nacre differently coloured. The nearest N. American 
species is A. implicata. It varies in shaj^e, but may generally 
be known by its somewhat solid growth, ventral gape, and 
salmon colour within. In the young shell, the tint is silvery, 
light or flesh colour. Long. 2-32, lat. 4>-'2A, alt. Vm. 

Sah- — ? Mexico, Lieut. Green. — Mazatlan ; not uncommon ; 
L'pool ^ Havre Coll. 

Tablet 523 contains 3 sp. elongated form. — 524, 2 s^). inter- 
mediate. — 525, 2 sp. produced ventrally, epidermis glossy with 
faint radiating lines of colour. — 526, 1 sp. with concentric 
striae near the umbos.— 527, 2 sp. distorted. 

Family MYTILIDvE. 

Dr. Dunker is at the present time engaged on a monograph 
of this family, of which the first part only (Monograph of the 
genera Septifer and Dreisscna) is as yet published. He has 
however most kindly identified the Mazatlan species with 
his own, and given me much valuable information concerning 
them. The young shells not oidy of different species, but 
even of different genera, very closely approximate each other. 

The measurements in this family are taken as follows ; long. 
from umbo to posterior extremity ; lat. fi'ora dorsal extremity 
of ligament straight across to ventral margin ; alt. thickness 
of closed valves. 



118 MAZATLAN BIVALVES 

Gentts MYTILUS, Linn. 

167. MyTILUS PALLIOPUNCTATrS, Dkr. 

M. t. subrectd, elongata, angusta, tumidiore, solida, plerumque 
vane detritd ; rugis inorementi concentricis sape instructa : 
epidermide crassd, cornea, fusco-olivaced, horridiore, radiatim 
fenuissime aratd, plus minusve indutd ; margine dorsali et car- 
dinali partim excurvato ; ligamento solido, extus umhones spira- 
liter ascendente ; pagind interna pulcherri me atro-purpured, 
■splendenie, apertiiram hi/ssalem versus pallidd, punctis 
sparsim valde i mp r c s s i s ; cicatricibus museularibus consjn- 
cuis, plerumque maxime corrtigatis. 

M. tenuiaratus, Dkr. ms., a prima manu. 

Shell long, swollen, rather straight, pointed, almost always 
rubbed at various angles, but when perfect exhibiting very 
fine radiating striidae, and sometimes much stronger concentric 
lines of growth. Interior of a lustrous dark purple, white near 
the byssus, punctured over the principal part of the siirface, 
as in many species of Semele. In the only adult specimen 
observed displaying the umbos distinctly, the ligament is seen 
to wind towards them outside the shell, presenting an appear- 
ance as in some Myoconchse. The muscular impressions are 
strongly marked, and often very rugose. The very young 
shells display neither striula; nor punctures, and are scarcely 
to be distinguished from the smooth varietj' of the next species. 
Long. 35, "hit. 1-38, alt. \Z. 
Hnb. — Mazatlan ; abimdant, but alwavs rubbed ; Lpool Sf 

Havre. Coll.—S. W. Mexico, P. P. C. 

Tablet 528 contains 7 sp., very yoimg, the smallest '04 
across. — 529, a sp. with numerous young outside, in situ. — 
530, 8 pairs and a valve of successive ages, normal form. — 531, 
5 do. elongated. — 532, 5 do. very narrow, elongated.— 533, 5 sp. 
curiously rubbed. — 534, 1 do. Avith one beak "20 shorter than 
the other. — 535, 1 do. persecuted by Litliophagi about the 
hinge. — 53(5, 3 do. distorted growth. — 537, 2 do. mantle cleft.— 
538, 4 sp. jun. shewing interior. — 539, 4 do. adult. 

168. Mttilus mfltifobmis, n. s. 

M. t. parvd, maxime variante, sed plerumque angusfd, 
prope cardinem tumidd, angulo perobscuro diagonali ; margine 



MAZATLAN BIYAIYES 119 

dorsali, prope cardinem perangulato, interne semper plus 
minusve crenato; margine ventrali planato seu incurvo ; 
siiperjicie modo liratd, liris plus minusve divaricantibus, modo 
striata, sen omnino Icevi ; colore pu rp ureo, ad marginem 
V entralem viridi: Ugamento curto, lato, effosso. 

Variat t. omuino viridi, j)lanata, liris tenuibus. 

"Crenarum indoles Modiolam sulcatam, Xf/w. aliasque 
species in mentem vocat ; statura similis est M. Lavalleano, 
D'Orh. (et M, Seuegalen3i = variabili, Krauss) sed satis ab eo 
differt," Dlr. M. glomeratus, Gould, (San Francisco) is about 
the size of this species, but more resembles M. edulis in form, 
and has no crenatious. 

This extremely changeable little shell might furnish materi- 
als for many species, if only a few picked specimens were 
examined ; but between the perfectly smooth and the deeply 
sulcated, the swollen and the flattened forms, there exists 
so regular a gradation that it is impossible to separate them. 
The yoxmg shell is shaped like Modiola. The smooth speci- 
mens closely resemble the young of M. palliopunctatus, but 
maybe distinguished by the presence of at least two or three 
denticles at the angle of the hinge line, and generally by 
a few more at the lunbos. These may often be seen in the 
closed shell by transmitted light. Frequently the entire 
hinge line, as well as the posterior margin, is crenated. The 
majority of yoimg specimens are smooth, and of adults sul- 
cated ; but often very minute specimens are plicated while 
those of (for the species) large size are smooth. The colour is 
generally purple, with a larger or smaller gi-eenish portion 
near the byssus ; but sometimes the purple is curtailed to a 
small patch, or is absent altogether. The shell is then gener- 
ally flat, with fine, branching fuiTOws : and might fairly be 
taken for a different and well-marked species, but for inter- 
mediate forms. The smallest specimen found measured scarcely 
"02 across ; an unusually large one, long. ''iS, lat. '^l, alt. '32. 

Some forms of the green variety might easily be taken for 
another species. Nevertheless they go through the same 
changes from nearly smooth to coarsely plicate, and often 
display puii)le at the commencement, or have purple at tlie 
margm. Occasionally a smooth purple shell suddenly changes 
to a plicate green one. The green shells are^enerally flatter, 
and often have the ribs somewhat nodulous ; in which state 
they are known from the young of Septifer Cumiiigianus by 
the absence of hairs on the epidermis. 



120 MAZATLAN BIVALVES 

Hah. — Mazatlan ; jun. abundant, rare adult, among sea weeda 

on Chamnp. Spondyli. Ostrese, Patella?, &c., or in the cavities 

of dead Litliophagi or Balani ; L'pool Sf Havre Coll. 

Tablet 540 contains 5 pairs and 6 pairs of valves, smooth 

form. — 541, 7 pairs and 6 pairs of valves, slightly Urate. — 542, 

11 pairs and 7 pairs of valves, lirate, jun. — 543, 7 pairs do. 

adult.— 544, 2 pairs and a valve strongly lirate. — 545, 2 sp. in 

crevices of Balanus and Lithophagus ; another Balauus has a 

crab in situ ; off Patella Mexicana. — 546, a group in situ 

among Balani, on M. palliopunctatiis. — 547, 2 sp. one ■with the 

surface in concentric layers, lilce Crepidula Lessonii ; the 

other with young Nullipore. 

Tablet 548 contains 5 pairs and 4 pairs of valves, greenish 
var., smooth form. — 549, 7 pairs and 4 pairs of valves, finely 
lirate. — 550, 4 pairs and 1 pair of valves, strongly lirate— 551, 
1 large valve, flat and broad. 

Tablet 552 contains 3 pairs and 2 valves, probably belonging 
to this species. 

Genus SEPTIFEE, Red. 

Vide Dunlc. Com. Sep. et Dreis., Marburgh, 1855. — Tichogonia. 
pars, Sossmassler, 1835. 

169. Septifee Cumingii, Eecl. 

Dimker, 3Io7iog. Sept. p. 8, no. IS. 

The few specimens found are too young to identify with 
accuracy. They are covered with fine, granulose ribs, with 
rather long bristly hairs rising up between. The umbonal 
plate is scarcely perceptible in the smallest shells. Hinge line 
crenate, as in M. multiformis. They closely resemble the 
yoxmg of S. bilocularis, but geographically agree better with 
the species quoted. The largest specimen nioasures only • 10 
in length. 
jj^7^ —Panama. Mus. Cuming.— Mazatlan ; extremely rare, 

jun. on Spondylus ; L'pool Col. 

Tablet 553 contains 3 pairs of different ages. 

Genus MODIOLA, Lam. 

Volsella, Scopoli, 1777.— Modiola, Lam. 1801.— Modiolus. 
Bisso, 1826. 



MAZATLAN BIVALVES 121 

170. MoDiOLA CAPAX, Conr. 

Journ. Ac. Nat. Sc. Phil. vol. vii. p. 242.— Hani. Descr. Cat. 

p. 236. 
Modiola spinifera, P. P. C, Cat. Prov. 
??Jun.— Mytilus spatula, 3n-e. in Zelt.f. Mai. 1848, p. 2. 

This species having been examined at every stage, from '03 
to 6 "5 in length, it is possible to give a tolerable account of its 
history. It begins life as a smaU white body, shaped Like 
Anodonta, but with the umbos very prominent and subcentral. 
The anteri,or part is then very large, the posterior very short 
in proportion. It soon however assumes the normal form, 
from which (in about 60 specimens examined) it varies but 
little. This differs from M. modiolus, in being slightly winged 
and strongly angled (about 130°) at the dorsal margin, and in 
being very much produced posteriorly. The epidermis when 
young is light green and smooth ; soon it changes to a dark 
chesnut colour, generally developing concentric rugose irregu- 
lar lines, and an abundance of hairs. These, in the very young 
shell are long, and not serrated ; but soon they become shorter 
in proportion, very strong and hard, and armed on one side 
with sharp, rather distant serrations. The cuticle is thin, 
smooth and glossy on the ventral part, and inside the margin. 
Colour at fii'st white, tinged with purple ; afterwards veiy 
iridescent and shaded with flesh colour and puce, with yellow 
near the ventral mai'gin. Ligamental pit deeply sunken, 
slightly bent, bounded by a strong ridge. IS'one of the Mazat- 
lan specimens were remarkable for size ; a valve however from 
La Paz in Dr. Gould's collection measures, lo?i(v. 6'5, lat.3' 
alt. 2-5. 

JIab. — San Diego ; in marshes and muddy shores ; Niittall — 
San Diego, Lieut. Green.— La, Paz, Col. Jewe^i!.— GaUapagos, 
Cumin</.^S. America, [?] Kellatt, in B. M.— S. W. Mexico, 
P. P. C. — Mazatlan ; rare, spinning a copious byssus, often 
attached to gravel or to each other, harbouring iMarginella. 
Ccecimi, Eulima, Odostomia, &c. ; L'iiool Col. 
Tablet 554 contains 10 pairs and a minute valve, various 

ages.— 555, 2 sp. adolescent.— 556, 1 do. adult'.- 557, speciitiens 

of the thorny hairs. 

171. Modiola Brasiliexsis, Chemn. 

Mytilus modiolus Brasilieusis, Chemn. Conch. Cah. vol. xi. 

pi. 205, f. 2020-1. 
Jan. 1856. «. 



122 MAZATLAN BIVALVES 

Modiola BrasOiensis, Hani. Descr. Cat. p. 234. — Dkr. in lit, 

Mj-tilus bicolor, Brug. Cat. 

Modiola G-uj-anensis, Lam. An. s. Vert. vol. vii. p. 20, no. 4. — 

Deles. Rec. t. 13, f. 9. 
Mytilus Guj'anensis, Desk. Enc. Meth. vers. vol. ii. p. 565, 

no. 24. 
= Modiola semifusca, Sow. (non Lam.) Gen. f. 6. — Mve. Conch. 

Syst. pi. 101, f. 6.— C. B. Ad. Fan. Shells, p. 251, no. 399. 

The typical form is remarkably constant in its characters, 
■while the ?var. is very changeable. Shell extremely thin, 
very rhombic, with the ventral and dorsal lines very straight, 
at an angle of about 30", a well marked diagonal ridge, and a 
somewhat straight posterior line, at a mean divergence of about 
105" from the dorsal line : with concentric furrows on the 
posterior part of the shell. This is coloured olive green ; while 
the anterior ventral i)art is smooth, and of an orange colour, 
with a narrow diagonal band of light orange, separating the 
two areas. Inside stained dorsally with reddish pui'ple. 
Umbos not decorticated. Long. 3"3, lat. 1'5, alt. I'l. 
Hah. — Brazils, Guyana, Dunlcer. — Venezuela, (Porto CabeUo 

et Caraccas,) Bay of Guasaqml ; Dr. Tarns, teste Dunker. — 

Mazatlan ; rare ; L'pool Sf Havre Coll. — Panama, rare, 

C. B. Adams. 

Tablet 558 contains 2 specimens, young and old. 



171 h. Modiola PBeasiliensis, var. mutabilis. 

Modiola semifusca, P. P. C, Cat. Prov. ; non Sow. ; nee 
Lam. An. s. Vert. vol. vii, p. 22, no. 11, (teste Hani.) 
M. 1 Brasiliensis, t. solldiore, epidermide atro-fusca indutd, 
apicibus pleriimque decorticatis ; stafurd mi nore :' forma ma- 
xime vanante ; margine ventrali recto seu ralde incurvafo ; 
plus minusiw elongatd ; angiilo diagonali indistinctiore ; mar- 
gine posteriore plus minusve cxcurvato. 

This shell suits exactly the description of Lam., but is 
distinct from the shell which Mr. Hanley states to be the 
true M. semifusca. According to Hanley, Dunker, and the 
first impressions I received from an examination of the speci- 
mens, this may be a rough Mater var. of M. Brasiliensis : there is 
however sufficient doubt to make it desirable that the varia- 
tions from other recorded localities should be accurately 



MAZATLAX BIVALVES 123 

investigated. Tlie IS". Zealand specimens appear intermediate 
between tliis and tlie tj-pical form, differing from tlie latter in 
being a flatter sbell, with, a well rounded posterior margin. 
This shell appears to take all allowable forms except the typi- 
cal one, the margins never being so straight and angular, and 
the diagonal keel being less impressed. The muscxdar impres- 
sions varj' sQmewhat, the posterior adductor being generally 
retort-shaped. The young shells display a fine olive spotting 
on a light groimd in the posterior part, which is always much 
produced. The largest specimen (distorted) measures long. 2 '5, 
lot. 1-2. alt. 1-1. 
Hah. — Mazatlau ; not common ; L'pool Sf Havre Coll. — P New 

Zealand, Si/icks. 

Tablet 559 contains 1 adolescent specimen, oval form. — 
560, 2 sp. broad, dorsal margin straight.— 561, 2 do. verj- 
long. — 562, 2 sp. slightly curved. — 563, 2 do. ventral margin 
much incurved. — 561, 1 large specimen, somewhat distorted. 

Tablet 565 contains a valve '05 long, of a oval form, with 
the concentric furrows clearly marked. 



Gencs CEENELLA, Brown. 

Crenella, Brotvn, 1827. — Lanistes, Stvains. 1840, (non Montf.) — 
Lanistina, G-ruT/, 1847. — Myoparo, Lea, 1833.— Modiola, sp. 
Lam. 

172. Ceekella coarctata, Dkr. 

Danker in lit.— No. 185, 190, Mus. Cuming. 

Comp. Modiola Chenuauus, i?ecZ. = Mytilus C, B. M. Cat. 

D'Orh.IIoll. -9.81, 754,. 
Comp. M. opifex, Sai/. 

Shell very A-ariablc in shape, but generally very tumid, with 
a medial constricting line, between which and the anterior 
part it is nearly smooth : the rest with rather fine radiating 
strise, divaricating on the diagonal angle, which in adult shells 
is clothed with a very coarse bristly epidermis. The stria; on 
tlie dorsal part, which is much hollowed by the protuberance 
of the umbos and tlie diagonal angle, are somewhat decussated. 
It appears to have the power of burrowing, like Lithophagus, 
'a specimen having been so found in the umbUical portion of 



12^1 5IAZATLAN BIVALVES 

Mxircx princeps. The youngest specimen measures "05 in 
length. A large specimen in Dr. Goidd's collection, (locality 
not recorded) measures (without taking into account the epi- 
dermis) „ long. -62, lat. "28, alt. -25. 

A long, narrow sp. „ '15, „ "OS, „ '06. 

A short, transverse sp. ,, *18, ,, *14, „ *12. 

Hah. — Gallapagos, Cinning. — Mazatlan ; in Spondylus calcifer, 

and burrowing in Murex regius, very rare ; L'pool Sf Savre 

Coll. 

Tablet 566 contains 3 sp. very young. — 567, 3 do. adolescent 
and adult, of which one display's concentric ridges of growth, 
like Crepidula Lessonii. 



Genus LITHOPHAGUS, Megerle. 

Lithophagus, Jfegerle von IFuhlf. 1811, JEntw. p. 69 ■.—Phil. 
Handb. Conch, p. 363: — Dk>\ Com. Sept. et Dreis. p. 2. — Lith- 
odomus, Cuv. 1817, Regne Anim. vol. iii. p. 136. — Modiola, sp. 
Lam. 

173. Lithophagus attenuatus, Desk. 

Modiola attenuata, Dcsh. in Lam. An. s. Vert. vol. \\\. p. 28, 

no. 25. Hani. L>e.9cr. Cat. p. 238. 
Lithodomus caudigcrus, var., Soiv. Gen. f. 3. — Rvc. pi. 99, f. 3. 

Known by its greatly produced, slender form, and by the 
incnisting beaks, which arc apprcsscd, smooth, closed exter- 
nally, but hollowed in the whole inner surface. Master 
Archer found a very large specimen, mcasiu'ing long. 4" 7, 
lat. 1-4, alt. -96. 
Hab. — Peru, ChUi, in .stones, Deshayes. — Mazatlan ; extremely 

rare, buiTowing in Spondylus calcifer, Imperator olivaceus, 

and Murex princeps ; L'pool Sf Havre Coll. 

Tablet 568 contains a sp. of Imperator olivaceus, broken 
across, and displaying a young L. attenuatus. with L. arista- 
tus.— 560, a very young sp. '13 in length. — 570, a di'awing of 
Mr. Archer's specimen, by Master John Jackson. 

174. Lithophagus calyculatus, n. s. 

L. t. tumidiore, eurta, in dorso valde angulatd ; umboni- 
bus apprcssis, inconspieuis ; parte' aniicd tumidd ; margine 



MAZATLAN BIVALVES 125 

ventrali incurvo ; epidermide fused, riigis concentricis parte 
posteriore instmctd ; incrustatione in parte posticd solidd, in 
lineas duas ah umhonihus decurrente,striis sagittiformihusincon- 
spieuis ad marginem directis ; in rostra solida prolongatd, 
appressa , maxim d parte non excav ata sed ad 
ap iee m alte effossa, quasi caly cem adhihentia. 

The only specimen found is in shape like L. arist. tumidior, 
but differs in the remarkable character of the incrustation. 
This lies in a solid triangular layer over the posterior part, 
with arrow-headed lines pointing away from the vertex of the 
triangle. At the sides, the coarse rugae of the epidermis are 
visible, ending in a diagonal line bounding the i)osterior part. 
The incrusting beaks are appressed, as in L. attcmiatus, but 
arc not hollowed within, as in that species, until the extremity, 
where there suddenly appears a deep cup, dividing the ter- 
mination into two knobs. This might at first appear as if bored 
into by another mollusk, biit (1) the excavation is not sideways 
but from the outer cud ; (2) the remains of the animal are 
fresh within ; (3) the lines of growth on the incrustation dis- 
play a simdar outline. Long. 'iQ, lat.'li, alt. '15. 
Sab. — Mazatlan ; 1 sp. in Spondylus calcifer ; L'pool Col. 

Tablet 571 contains the specimen. 

175. LiTHOPHAGUS PLUMULA, Hani. 

Proc. Zool. Soc. 1844, p. 17. 

Modiola plumula, Haul. Descr. Cat. p. 239. 

Comp. L. Isevigatus, B. M. non Quo?/ Sf Gaim. (Cape Upstart, 

Jukes.) 
Comp. L. rugiferus, Dkr. in lit. Mazatlan (teste Cuming) : 

"differt a L. plumula forma et incrustationis indole diversa. 

Margines cardinalis ct basalis baud paralloli, pars anterior 

minus inflata est. Latus basale rugis instructum est." Dun- 

Jcer. Spec. unic. in Mus. Cum. no. 172. 

The species is known by the remarkable character of the 
incrustation, which for the most part presents the arrange- 
ment of a feather in lines running out on each side from a 
midrib which joins the umbo to the posterior end. The in- 
crustations form beaks beyond the shell, appressed but not 
prolonged or hoUowed within. Its texture is sometimes 
tolerably solid, sometimes in a branching network. It does 
not present an organized structure under the microscope, nor 



126 MAAZTLAN BIVALVES 

is tlie pattern constant, tliougli there is a general adherence to 
a particular plan. It often presents the appearance of grains 
of detritus cemented together by animal matter, these grains 
also covering the body of the shell much more coarsely than 
in L. aristatus. It is thus that the yovmg shells can generally 
be separated ; the epidermal tubercles being much larger, and 
the concentric wrinkles stronger. The number of specimens 
however was not large enough to ascertain these points with 
precision. The differences in the pattern of incrustation do 
not accompany those in form. The shape presents the same 
two extreme varieties, gracilior and tumidior, as in L. aristatus. 
The parallelism of the margins also is not constant. The bur- 
rows are in most respects like those of L. aristatus, q, v. They 
are shaped like the shell, and allow very little space for the 
opening of the valves. The orifice is almost close to the ex- 
terior, and is not bilobed. The largest iierfect specimen 
measures long. 1'86, lat. '53, alt. '5. A very tumid sp. in 
Mr. Darbishirc's Col. measures long. 1'9, lat. "9, alt. '6. 
Hah. — Panama, in Spondyli, Cuming. — Philippines [?], Han- 
ley. — Mazatlan ; rare in Spondyli, verj' rare in Chamse and 
Patella Mexicana ; L'jipool Sf Havre Col. 
Tablet 572 contains 6 pairs young, the smallest '08 in 
length.— 573, 4 sp. adolescent and adult, typical form. — 574, a 
sp. in situ, burrowing in the attached part of the Spond3'lus 
calcifer : portions of the rock remain, which appear to have 
been bored by Pholads ; a burrow is seen of P. calva. — 575, 
2 fragments shewing the extremities of the burrows which are 
more nearly roiuid than in L. aristatus. — 576, fragments illus- 
trating shell structure. — 577, do. incrustations. 

Tablet 578 contains 3 sp. different ages, var. gracilior. 
Tablet 579 contains 1 pair and 2 valves do., var. tumidior. 
Tablet 580 contains a sp. with the anterior part less swollen, 
and the lines not parallel. 

176. LiTHOPHAGUS ABISTATUS, Sol. 

Mytilus aristatus, Dillw. Descr. Cat. 1817, vol. i, p. 303, no. 8.— 

Solander, ms..— Wood, Ind. Test. pi. 12, f. 8. 
Lithodomus aristatus, Forbes Sf Hani. Br. Moll. vol. ii. p. 212. 
Enc. Meth. Vers. pi. 221, f. 8, a, b. 
Le Ropan, Adans. Sen. p. 267, pi. 19, f. 2. 
Mvtilus lithophagus striatus, J. Soiv. Linn. Trans. 1804, 

vol. viii. p. 274, pi. 6, f. 2, 3-5. 



MAZATLAN BIVALVES- 127 

Modiola caudigera, Lam. 1819, An. s. Vert. vol. vi. p. 27, no. 23. — 

Hani. Bee. ShelU, p. 228.— Phil. Ahhild. Conch, vol. ii. 

p. 149, pi. 1, f. 5. 
^lytilus Ropan, Desh. in Lam. loc. cit. (note.) 
Lithodomus caudigerus, SotcGen. f. 4. — Eve. Conch. Si/st. 

pi. 99, f. 4. 
Lithodomus litkophagiis, Flem.' Br.' An. p. '414. — Br. Mar. 

Conch, p. Ill : (nou auct.) 

The Mazatlan specimens vary 'greatly among themselves, 
being sometimes nearly as narrow as L. attenxxatns, at other 
times apiDroaching iu form L. cinnamomeus ; yet they offer no 
marks by which they can be separated from the long known 
W. African species. It begins life, (as may be seen on tracing 
tlie lines of growth in the youngest specimen '035 long.) shaped 
like Unio margaritacea, but more swoUen. Soon however the 
anterior portion is shoi'tened propoi'tioually, while the pos- 
terior part is prolonged. The umbos from the earliest period 
are quite flat, and are soon covered by a slight reflexion over 
them from the anterior margin. The shell is extremely thin, 
and covered with a glossy chesnut epidermis, tui-ned in over the 
margin. Soon tubercles appear in regular rows on the epider- 
mis, which seem to furnish the foundation for the accretion 
which presently commences. This accretion appears under 
the microscope as if formed by the agglomeration of i)articles 
of the shell into which the creature has bored. It soon covers, 
more or less, the whole of the epidermis, and is deposited in a 
thick coating at the posterior end. Here, beginning to appear 
generallj^ when the shell is about ' 12 long in the form of small 
tenninal knobs, it gradually develops into two shelly spikes, 
which twist more or less round each other, and are somewhat 
but never wholly opposite at their bases. These spikes vary 
greatly in size and shape, sometimes attaining nearly half the 
length of the shell. They may generally be seen peeping out 
from the orifice, which is somewhat bilobed, though not ♦so 
distinctly as in Gastrochsna. "When the matrix in \\hich they 
burrow is not sufficiently solid, they line that part Avith shelly 
matter, which occasionally projects as a separate case, as in the 
British Gastrocha?na3. This lining is generally found where 
one burrow crosses another; it was not however imiversal 
when crossing the empty jyart of Imperator. Li this shell 
the creatiu-e generally has the instinct to burrow throvigh the 
thick sutural portion, or else down the axis. In old specimens, 
the burrow is often lined with a grayish deposit, apparently 



128 MAZATIAN BIVALVES 

intermediate in texture between the sliell and the calcareous 
incrustation. This deposit extends about half way down the 
burrow. This species and L. i)lunuda are always fouiid close 
to the outside of the matrix ; but they do not affect the same 
situations. In Patella Mc.xicana, L. aristatus is often very com- 
mon. In about one fifth of an aged limpet Mr. Darbishire found 
13 large specimens, without reckoning emi)ty biuTows. Here 
however, and in Chama, L. plnmula is extremely rare ; while 
in the thick lower valves of Spondylus it is not imcommon. 
The biuTows are shaped nearly as the shell, with no power of 
rotatory motion, and very little scoi^e for opening the valves. 
Traces of the foot mark are very rare. The shell, when adiilt, 
is more or less incurved ventrally, and angled dorsally ; tumid 
at both extremities. Shell (without epidermis and incrustation) 
extremely thiu. The largest specimen found perfect measures 
long, (with the beaks) 1"56, lat. "47, alt. "4. 
Hah. — Senegal and West Indies ; foimd in ballast, London 
roads (!), Forhcs. — Senegal, in shells of Balani, Adanson. — 
Abundant in Ostrea iridescens, W. coast Africa, Stutchhury : 
— do. do. Ajiamaboa, B. j\I. — Guinea, Tarns. — Eed Sea, 
DunJcer. — St. Thomas, Hornhecl-. — Mazatlan ; abundant in 
Chama?, Spondyli, Ostrea iridescens, Patella Mexicana and 
discors, Imperator unguis and oLivaceus, Strombus galea, 
&c ; Upool Sf Havre Coll, 

Tablet 581 contains 11 pairs, and 8 pairs of valves, extremely 
young. — 582. 5 pairs and 4 pairs of valves, a stage older. — 583, 
8 pairs, and 3 pairs of valves, do. — 584, 6 sp. adolescent. — 585, 
5 do. adult. 

Tablet 586 contains 6 young sp. in situ, burrowing in Patella 
Mexicana. — 587, 1 do. do. with the beaks detached, shewing the 
glossy epidermis beneath. — 588, 2 adult sp. in P. jNEexicana. — 
589, fragment of P. INIcxicana, displaying shelly lining to 
tubes. — 590, another fi'agment, in Avhich a Lithophagus had 
bored '6 beyond the inner surface ; the limpet having defended 
itself from its pursuer by fresh layers of shell. — 591, 4 sp. of 
Patella discors, variously distorted by Lithophagi. — 592. Fis- 
surella rugosa and F. alba, similarly attached. — 593. Mytilus 
tenuiaratus, with 3 Lith. in situ : part of the mussel being 
broken away displays its jasper-like texture, as well as the 
shelly lining of the tube. — 591. 3 sp. of Imperator unguis, with 
Lith. in situ ; in one, they have just reached the interior of 
the mouth ; anotlier is bored across the apex ; the other, not 
finding i-oom within, has increased its size by raising a tumulus 



MAZATtAN BIVALVES 129 

outside. — 595, Imp. olivaceus, mtli bore across tlie apex. — 596, 
do. with 5 Litli. in situ. — 597, do. witli upper part broken 
across, sliewing an inner partition made by the animal to 
avoid the attacks of 2 Lithophagi ; also a young Gastrochsena 
in situ. 

Tablet 598 contains extremities of sheUy tubes. — 599, a large 
number of posterior extremities, to illustrate the variations of 
form. — 600, fragments to shew the different laj^ers, viz. inter- 
nal shelly layer, medial epidei'mis, and external coating. 

LiTHOPHAGXJS AEisTATUS, var. GEACiLiOE : forvid exiUoH, 
"L. attenuatum" simulante, seel aijpendicihus curvatis. Long. 
1'15, cujus "22 a2wendix est, lat. '3, alt. '33. 
Tablet 601 contains 7 sp. of different ages. 

LiTHOPHAGXJS ABisTATCS, vav. TUMiDioR ; formd tumidiori, 
curtd, ad L. cinnamomeum prope accedente. Long. 1*54, cvjus 
*35 appendix est, lat. '53, alt. '58. 

Tablet 602 contains 3 pairs and 1 valve, very young. — 603, 
3 sp. yoimg and old. The extreme form of this ? variety was 
naturally regarded by Dr. Dunker as a distinct species. 



177. LlTHOPHAGtrS CINNAMOMEUS, CJiemn. 

Mytilus cinnamomeus. Conch. Cah. vol. viii. pi. 82. f. 731. — 
'i:nc?/cl. pi. 221, f. 4>.—DesL Enc. Meth. Vers, pi. 2, p. 566, 
no. 25. 
Modiola cinnamomea. Lam. An. s. Vert. vol. vii. p. 25, no. 18. — 

Hani. Descr. Cat. p. 238. 
Lithodomus cinnamomeus, B. M. Cat. Cub. Moll. p. 45, 

no. 539. 
Lithophagus cinnamomeus, Dlr. in lit. 

One perfect valve only was found that could be certainly 
identified with this species.- So weak however was the shelly 
matter, that on being placed in hot water the cuticle ran into 
shreds, breaking it to pieces. According to Dunker, the 
species is of wide distribution, and variable in colour, being 
brown, chesnut, or cinnamon. This specimen was blackish 
brown, about an inch long. 

Sab. — ^lauritius, Lamarck. — Philippines, Dunker. — Cuba, 
Sagra. — Central America. Dunker. — St. Thomas, Horn- 
beck. — Venezuela, (Porto Cabello,) Tarns. — Mazatlan ; ex- 



130 MAZATLAK BIVALTES 

tremely rare, burrowing in Chama ; Lpool Col. — Fossil, 

near Eome, Lamarck. 

Tablet 604 contains tbe remains of the valve. 

SuB-GENTJs LEIOSOLEISnTS. 

Animal profimde in matricem 'penetrans, came'ramcapacem. 
politam excavans, 'partem derelictdm explens prater tiihttm 
IcBvem partim hilohatum, ? siphones longos tenentem. Testa 
Lithophago sirn His. 

If the animal, when examined, proves to have long, excur- 
rent siphons, it must take generic rank perhaps in the neigh- 
bourhood of Mytilimeria, Conr. 

178. Leiosolenus spatiosi's, n. s. 

S. t. dactj/liformi, tenuissimd, curtiori ; postice concentrice 
undulatd ; umhonihiis celatis ; incruMatione calcaria, tenui, 
cequaliter totam superficiem tegente, plerumqiie pustulis trans- 
verse conjluentihus munita ; marginihus antice et postice rotun- 
datis, ventraliter suhexcurvatis ; Tinea cardinali pralonga, 
onargine dorsali curvato, subangidato, curtissimo. Camerd 
obovaU, spatiosd, nitidissimd : tiibo nitido xjl.us minusve elongato, 
juxta cameram contracto, postice bilohato. 

Several chambers of this remarkable shell were found b^' 
Mr. Darbisliire ; always in the lower valves of Spondylus, and 
generally open as if part of the buri'ow were excavated in the 
rock. This may account for the loss of the shells except in a 
single instance. In the largest specimen, presented by him to 
the Br. Mus., are seen two chambers, which, from the long 
bilobed pipe of one of them, might be taken for the work of 
an enormous Gastrocha?na. The pipes are however perfectly 
smooth»within, while in Gastroch.Tna they are corrugated. The 
bilobation is only at the extremities, the rest of the pipe being 
irregularly circidar, and much contracted at its jimction with 
the cell. As there is no evidence of paUial sinus in the shell 
(though it ma.y possibly exist,) it is probable that the con- 
traction of the siphons takes place outside the body of the 
animal. From an examination of a specimen broken in the 
line of axis of the cell and pipe, it appears that the creature 
begins life with the shortest possible tube and a somewhat 
conical cell : as it burrows deeper, it not only fills up the cor- 
responding posterior space with concentric layers of shelly 
deposit, pierced by the pipe ; but also proportionally shortens 



MAZATLAN BIVALVES 131 

the cell, leaving it of a produced ovoid. It is large enough to 
allow of considerable expansion and revolution of the shell 
within : but so far from showing marks of friction, the internal 
coating of both cell and pipe are very glossy. The deposit 
is sometimes '4 thick. 

The animal is gregarious : ten burrows having been found 
in one Spondylus valve, of which six appeared of more recent 
date than the rest, being carried across the others. One 
of these, in ci'ossing a burrow of its predecessor, had obhterated 
one half of 'the valves of the dead shell, and built-in the remain- 
ing portion with the wall of the new cell ; another had cut 
across and cemented a Ciimingia in the same way. 

The shell is short, bent, scarcely angled at the dorsal margin, 
well rounded at the ends, and slightly excurved in front. The 
hinge line is very long, with the usual shar^i ridge within. It 
is not sufficiently fresh to display the muscular impressions 
distinctly. There are no proj ecting incrustations ; the deposit 
being thin and equally diffused. The shape of the shell is not 
such as would have been j)redicated from the form of its habi- 
tation ; which had given rise to many sui-mises, before the 
shell now described was foimd entombed, without possibiUty of 
error. This shell, which is somewhat young, measures long. 1 " 5, 
lat. '55, alt. '47 ; its cell is "65 across. The largest cell measures 
Idnrj. 3'2G, lat. 1'2: its tube, long. 1'6, lat. (in the middle) *3, 
alt. -2. 

Hah. — ^^Mazatlan ; extremelv rare, in attached valves of Spon- 
dylus calcifer ; L'pool Col. 

Tablet 605 contains a young shell "06 in length, which may 
belong to this species, though its affiliation cannot be deter- 
mined without a series. It may possibly be a young L. cin- 
namomeus. ^ilso a fragment of a large shell. — 606, Spondylus 
valve, containing the two largest bui'rovvs, unfortunately broken 
in obtaining a cast : also burrows of Gastrocha;na truncata, &c. 

179. Leiosolenus , sp. ind. 

One specimen was found by Mr. Darbishire, differing from 
the rest in the following particulars. Shell much shorter, 
broader, and with the hinge line and dorsal margin at a much 
smaller angle. Cell not so smooth, with dark gray Avails, 
scarcely polished. Pipe emerging without any contraction, 
but with a raised ridge within the cell. The shell being very 
much decomposed was unfortunately broken to pieces in 
extraction. 



132 MAZATLAJI BIVALVES 

Hab. — Mazatlan ; 1 sp. in Spondylus ; L'pool Col. 
Tablet 607 contaius a sketch. 

Family ARCADE. 
Genus AECA, Linn. 

Area, pars, Liym. Lam. Area, Swains. 1840— Senilia, Gray, 
1848. 

The Area; appear to divide themselves into two natural 
groups, those which hve freely in sand or mnd. like cockles, 
whose name they commonly bear ; and those which live nest- 
ling in crevices or affixed to rocks by a horny byssoid pedal 
appendage. The former have stout, regular, strongly ribbed 
shells, and are considered by Swainson the typical species ; 
the latter have irregidar shells, generally with a' thin or shaggy 
epidermis, and a more or less developed ventral gape. These, 
which are the tj-pical species of most authors, form Swainson's 
genus Byssoarca. 

180. Aeca geaxdis, Bt'od. Sf Sow. 

Zool. Journ. vol. iv. p. 3G5.— i?ce. Condi. Ic. pi. 1, f. 4,.— Hani. 

Descr. Cat. p. 1(50.— i?. M. Cat. D'Orlj. Moll. p. 82, no. 729.— 

C. B. Ad. Pan. Shells, p. 259, no. 417. 

This species, the "W. Pacific analogue of the East Indian 
A. senilis, is known from it by the greater nimiber of ribs, 
(25-30) and by the teeth which are comparatively narrow. 
They are however wider than in A. tuberculosa. The shell 
in its young state is generally subaniuilateral, subquadrate, 
often slightly injequivalve, with the cpidemiis for the most part 
smooth and persistent, displaying here and there hairs, and 
cancellating scales across the grooves. The ribs are then often 
granulose. As it advances to maturity, the posterior part 
generally becomes much produced, till the aspect of the shell 
becomes very insequilateral, and not imlike that of A. tuber- 
culosa. It may however always be distinguished from it by its 
greater solidity, the smaller number of ribs, and by the grooves 
which nearly equal the ribs in breadth. The epidermis grad- 
ually becomes thick and rough, forming in concentric layers, 
wliich are very conspicuous across the grooves. The umbonal 
portion generally becomes decorticated. The ligament is 
coarse and solid, filling up the whole of the hinge area except a 



AIAZATLAN BIVALVES 138 

smooth border all round. The teeth are normally numerous, 
strong, and nearly straight, scarcely shewing the middle point. 
The extreme teeth are sometimes broken into tubercles. Often 
however they become very small or even obsolete. Sometimes 
long callous processes are formed inside the line of teeth, 
which, when much developed whUe the teeth are obsolete, 
present a striking resemblance to the fossil genus jMacrodo:.. 
.Uthough the JMazatlan shells are not so large as those from 
Panama (one valve of which weighed 2'25lb, C. B. Ad.), yet a 
single pair weighed 3' 6 lb. 

In the following measurements, the length is taken (1) from 
the umbo to the middle of the opposite margin, and (2) from 
the middle of the hinge to the nearest point across. The fifth 
column gives the distance between the umbos, 

long. (1) long. (2) lat. alt. umb. dist. 
Younge.st sp. transverse, "85, "73, 1'14, '7, "06. 
Young sp. produced, 1", "86, 1'18, "77, '1. 

Largest sp. o", 3-2, 5-8, 4'7, 1'3. 

Ovate sp. 3-65, 27, 4-9, 3-, bb. 

Inflated sp. 3-4, 2-1, 4-2, S'S, V7. 

Hah. — ^Eeal Llejos, Bay of Guayaquil, &c. Gaming, Hinds. — 
Ecuador, Guayaquil, Fontaine, D'Orbigny. — Panama ; rare 
hut large, half buried in mud and smaU alga?, under trees, a 
httle above half tide level ; C. B. Adams.— M&z-dXldiQ. ; very 
common ; L'pool Sf Havre Coll. 

Tablet 60S contains 5 specimens, square form, young. — 609, 
2 sp. do. adult. — (510, the largest sp.— 611, 4 sp. .voimg, sUghtly 
transverse. — 612, 1 do. adult.— 613, 1 do. large.— 614, 4 s]). 
young, produced, shape approachmg A. tuberculosa.— (31.5, 1 do. 
adult.— 616, 4 sp. transverse.— 617, 4 sp. gibbous, young.— 618. 
1 do. adolescent. — 619, 2 do. adult. 

Specimens exhibiting the inside. Tablet 620 contains 3 sp. 
young. — 621, 1 do. valves interlocking.— 622, 1 do. adult, broad 
teeth, "Macrodon" processes distinct. — 623, 1 do. hinge nar- 
rower, callosity within, running from umbo.— 621, 1 do. hiuge 
and processes developed, margin in layers, probal)ly from 
intrusion of dirt. — 625, 1 do. teeth obsolete, processes distinct. — 
626, 1 do. hinge line narrowed off, teetli only shewing at ex- 
tremities. — 627, 1 do. posterior hinge margin fractured and 
partially mended, shewing the teeth of an earHer age. 
Feb. 1856. n 



134 MAZATLAX BITALTES 

181. AeCA MrLTICOSTATA, Sou\ 

Proc. Zooh Soc. 1833, p. 21.— Ri-e. Conch. Ic, pi. 4, f. 23.— 

Eanl Rec. Shells, pi. 19, f. 12. 

One very fine specimen of this shell was found by ]\Ir. Archer. 
It differs from A. grandis in being much lighter, with more 
numerous ribs, and a squarer form. Long.'2'Qo, lat. Z'lQ, 
alt. 2 -36. 

Hab.—Gvli of Tehuantepee, 12 fm., C«/«/;?5r— Mazatlan ; ex- 
tremelj' rare ; IS pool Col. 

Tablet 628 contains a very small valve, "15 across, which 
may belong to this species.— 629, a drawing of Mr. Archer's 
specimen. 

182. AkCA ? LABIATA, SoiO. 

Proc. Zool. Soc. 1833, p. 2l.—Iive. Conch. Ic. pi. 1, f. 7.— 

minJ. Descr. Cat. p. 160.— J5. Jf. Cat. B'Orb. Moll. p. 81, 

no. 720. 
Gomp. A. labiosa, Soic. loc. cit. — Rve. Conch. Ic. pi. 10, f. 67. — 

Hani. Descr. Cat. p. 159, pi. 19, f. 3.— i?. JLT. Cat. B'Orh. 

Moll. p. 81, no. 720. 
Comp. A. incongrua, Sai/, Journ. Ac. xsat. Sc. Phil. vol. ii. 

p. 268.— B««Z. Descr. Cat. p. 159. 

The three species above quoted are veiy nearly allied. The 
two specimens found in the L'pool Col. by ^Messrs. Hibbert 
and Archer, before it fell into the dealer's hands, are exactly 
like the specimens brought from Florida, by J. J. Audubon. 
Shell with distant beats, and strong ligament filling up a large 
rhomboidal area. Shape subangular ; tubercles absent from 
the angular part, also from the front of the smaller valve. 
Teeth rather broad. Louff. (from umbo) 1"23, lat. 1'3, alt. 1"04. 
Hah. — Eeal Llejos and Tumbez, Peru, in sandy mud, 7 fm, 

Cuminf/. — ]\Iazatlan ; extremely rare ; L'jiool Col. 

Tablet 630 contains a specimen, presented by J. Hibbert, Esq. 

183. Abca bifeoxs, n. s. 

A. t. turgidd, subquadratd, tenui, maxlme inctqnivalvi, postice 
angulata, umbonihus hand di.ttantibus ; albd, epidcrmide leevi , 
olivaced indittd ; cosiis circiter xxx., in testa jitniore omnibus 
tuberculosis ; in adultd solum viii. — x. anticis, reliquis Iwvibus ; 
costis ventralibus in valvd minore par vis, rotundatis. 



MAZATLAN BIVALVES 135 

interstitia hand cequantihus ; in valva majore planatis , 
mbohsoletis, interstiiiis minimis ; ligamento solido, aream rhom- 
hoideam implente ; dent. card, in lined cnrvd,parvis ; margine 
valvcE majoris effosso, valvam alteram recipiendo ; costihus prop- 
ter temiitatem intus monstrantihus. 

The above description is written from three beautiful ex- 
amples in the Museum of Hugh Cuminjr, Esq. Fragments 
only of young shells were foimd iu the L'pool collection, which 
however probably belong to the same species. It is known 
from A. incongrua and its congeners by its hght structure, 
smooth epidermis, and especially by the ribs which are very 
narrow on one valve with wide interstices, on the other broad 
and flat, scarcely divided. There is a corresponding difference 
in the crenations of the valves. Long. 1'55, lat. 1"73, alt. 1'32. 
J2ai.— Mazatlan, Mus. Cuming.— Do ; fragments on Spondylus 

calcifer ; L'pool Col. 

Tablet 631 contains the fragments. 

184. AkCA TUBEECrLOSA, Sow. 

Froc. Zool. Soc. 1833, p. 19.—Milll. Sz/n. Test. Tiv. p. 179.— 
Phil. Ahhild. I. pi. 1, f. I.—Bve. Conch. Lc. pi. 3, f. 18.— 
Sanl. Descr. Cat. p. 161, pi. 18, f. 53.— C. B. Ad. Fan. 
Shells, p. 263, no. 425. 
Comp. Area similis, C. B. Ad. Fan. Shells, p. 262, no. 422. 

Shape varying from subquadrate, subfequilateral, to very 
transverse, with the posterior i^art much produced ; sometimes 
flattened, sometimes extremely swollen. Eibs very numerous 
(about 36), close, slightly and irregularly tuberculous, often 
shewing concentrie ridges of growth. Epidermis dark brown, 
coarse, deciduous near the umbos, with short scaly hairs in 
the intercostal spaces, and sometimes finer hairs on the pos- 
terior part. Inside white : teeth numerous, rather broad. 
Ligament coarse, solid, entirely filling up the rather narrow 
area between the beaks. Hinge line sometimes rounded off. 
The largest specimen measures /owf^. 2 78, lat.3'G7, alt. 2'5. 
A squarish „ „ „ 2', „ 2-35, „ 1-5. 

A swollen „ „ „ 2-45, „ S', „ 2-35. 

ffab. — Eeal Llejos, at roots of Mangrove trees, low water, 
Cuming. — Panama, in impalpable mud, under a Mangrove 
thicket, near high water mark, not uncommon, C. B. Adam^. 
— Mazatlan ; vcrj' common ; Lpool Sf Havre Coll. 



136 MAZATLAN BIVALVES 

Tablet 632 contains 2 specimens, squarisli form. — 633, 5 do. 
fine flattened pjrowth. — 634, 5 do. normal growth. — 635, 3 do. 
swollen, produced. — 636, 3 do. swollen, oval.— 637, 4 sp. shewing 
the inside, one normal, another with the anterior teeth irregu- 
lar, the third with the teeth neai'ly obsolete, the fourth do. 
quite obsolete, apparently from disease. 

185. Aeca eeversa, G-raij. 

Sow. in Proc. Zool. Soc. 1833, p. 210.— Mull. Sijn. Test. Viv. 

p. \m.—Rve. Conch. Ic. pi. 1, f. b.—B. M. Cat. UOrh. Moll. 

p. 81, no. 722.— C. B. Ad. Pan. Shells, p. 261, no. 421. 
Area hemicardium, Koch in Phil. Ahbild. pi. 1, f. 1. 1843. 

This aberrant species is known at once by the truncation of 
the anterior portion. The ligament is cut off at right angles 
between the umbos, (which are not distant) and is solid, occu- 
pying the posterior area. The posterior line of teeth begins 
from the umbo ; the anterior begins from a point nearer the 
middle, lying within the other, and is veiw short. There is a 
.slightly developed ridge bounding the anterior adductor, as in 
Cuoullani. Loiig.1'7, laf. 2'lo, alt. I'o. 
Hah. — Tumbez, Peru, in soft mud, 7fm., Cuminff. D'Orhiy- 

»//.— Panama, extremely rai-e, C. B. Adams. — Mazatlan ; 2 

line specuncns only were found by Mr. Archer ; L'lmol Col. 

Tablet 638 contains one specimen. 

186. Aeca Pbeevifeons, Soto. 

Proc. Zool. Soc. 1833, p. 22.— i?cc. Conch. Ic. pi. 1, f. 6. 

In consequence of the internal characters not being given, 
the species cannot be determined with accuracy, but it fits the 
description as far as it goes. Epidermis as in A. nuilticostata, 
very finely striated along the radiating ribs, coarselj' rugose 
between. Umbos approximate ; ligament very long and nar- 
row. Inside white, with a subumbonal stain as in A. emar- 
ginata. Posterior hinge teeth in a long slightly curved line : 
anterior somewhat twisted, in a short line at a decided angle. 
The teeth resemble A. reversa. Long. "59, lat. "48, aU. '33. 
Hah. — Tumbez, Peru ; in soft mud, 7 fin.; Ci'.ming. — Mazatlan ; 

l-flj). on Murex nigritus, witli A. emarginata ; L'-pool Col. 

Tablet 63!) (H)ntains the specimen. 



mazatlan bivaltes 137 

187. Aeca emaeginata, Sow. 

Proc. Zool. Soc. 1833. p. 20.— Mill/. S//>i. Test. Viv. p. ISO.— 
Eve. Conch. Ic. pi. 4, f. ^Q.-Sanl. Descr. Cat. p. 161, pi. 18, 
f. 60.— 5. M. Cat. UOrh. Moll. p. 81, no. 723.- C. B. Ad. 
Fan. Shells, p. 258, no. 415. 

Altliougli classed by Sby. among tlic rcquivalves, he rightly 
describes it as ina;quivalve, tbe posterior ventral part consider- 
ably overlapping, even in yonng sliells. Umbos separated by 
a narrow triangidar area. Ligament in very young sbells only 
adhering posteriorly : afterwards filling a triangular space to 
the beaks ; when adult displaying also a thin film on the 
anterior portion. Teeth strong, not very numerous, both rows 
forming a regular, slightly curved line, not reaching into the 
wing. Emargination not developed in young shells, variable 
in adult. Very young shell smooth : afterwards beautifully 
coloured with irregvdar dark chocolate undidating bands, and 
an interior spot radiating from the umbos. The smallest 
specimen is '03 across: the largest (valve) long. "5, lat. '9. 
alt. '35. 

Hah. — xitacamas, Real Llejos, XipLxapi, Panama ; in sandy 
mud, 6-8 fm. ; Cmninrj.—'Do. ; D' Orh/f/ii//.—Fa.niima, very 
rare ; C. B. Adams. — Gulf of California, Mus. Cuming. — 
Mazatlan ; young on Spondylus calcifer, adult on Murex 
nigritus, extremely rare ; L'pool Col. 
Tablet 640 contains 4 sp. young. — 641, the largest valve. 

188. Aeca tjun., sp. ind. 

Comp. Byssoarca alternata, Sow. Proc. Zool. Soc. 1833, p. 17. — 

(Area a.) C. B. Ad. Pan. Shells, p. 257, no. 413. (Hah. 

W. Columbia, Cuminy : Panama, C. B. Adams : Mazatlan, 

Col. Jewett.J 

Tablet &42 contains 2 small opposite valves, the largest 'Of? 
across, remarkable for the structure of the hinge, which is 
bounded not by one but by two lines, one of which radiates 
from the umbo, and between which probably the ligament is 
fixed. Outside are concentric irregular lines near the umbo, 
afterwards about 40 well rounded regular ribs, with equal 
interstices and strong plications within. It is clearly a young 
shell ; too young to determine even the generic section with 
confidence. 
Hah. — ]Mazatlan ; off" Spondylus calcifer, extremely rare ; 

Jj'pool Col. 



138 MAZATLAN BIVALVES 

Genus BYSSOAECA, Siaains. 

Ai-ca, sp. typ. Linn., awc^.— Cibota, Brown. — Daplme, Poll.— 
NavicuJa, Blainv. 1818 (teste Gray.) non Spix. — Byssoarca, 
Swains. 1835.* 

189. Btssoaeca Pacifica, Sow. 
Proc. Zool. Sor. 1833, p. 17. 
Area Pacififa, Pve. Conch. Ic. pi. 11. f. Ib.Sanl. Bee. Shells, 

pi. 18. f. 59.— i?. M. Cat. B'Orh. Moll. p. 8 2, no. 735. 

Tliis magnificent species is known from B. Noffi and its 
congeners by its very large size, extremely swollen develop- 
ment of the posterior portion, coarse ribs, large indentation 
near the posterior hinge-angle, and tbe strong laminated giU- 
like epidermis, which lies in verj^ conspicuous striated folds 
round the large byssal opening. It varies greatly in shape, 
sometimes not displaying the above characters, but presenting a 
tolerably imiform outline and small pedal oijening. The byssal 
foot has a hard horny case, grooved inside. It scarcely pro- 
jects "beyond the shell. Teeth extremely numerous, sharp, 
generally narrow, sometimes rather broad. Ligament very 
thin, distributed in a lozenge over the whole area except the 
margin, with coarser lines radiating from the umbos, and 
sometimes others irregularlj^ crossing these. The smallest 
of the specimens measures long. '77, lat.\'^, alt. '8. 

A narrow sp. „ 2*2, „ 3-fi, „ 2-8. 

The largest sp. ,, 3", ,, 5'5, ,, 4'. 

This sj}. measures inside from middle of hinge to ventral 
margin 1"3 ; from posterior end do. 2'4 ; projection of umbos 
1'2 ; distance between umbos 1'8. 
Hah. — St. Elena ; on rocky ground, 6-18 fra., adhering to 

each other in hxrge bunches ; Cuming. — Ecuador, St. Elena, 

D'Orhignij. — Bijooga Is. Capt. BeavJ'ort, B. M. — Mazatlan ; 

rare, but very fine ; L'pool Col. 

Tablet (513 contains 1 valve, "03 across, probablj' belonging 
to this species. 

Tablet 6-14 contains 2 sj). young. — 615, 2 sp. adolescent ; 
'Macrodon' teeth, brancliing from the centre, very conspicu- 
ous on one side ; in the larger sp. the hinge teeth are abnor- 
mally broad. — 646, sp. not produced, incrusted with coral. — 
647, the largest sp. — 6-18, stoue incrusted with Brj'ozoa, with 
byssal foot attached. 

• Mr. A. Adams names these shells Area, and the previous species Scapharca, Gray. 



MAZATLAN BIVALVES 139 



190. Btssoaeca mutabilis, Soio. 

Froc. Zool. Soc. 1833, p. 17. 

Area mutabilis, Hve. Conch. Ic. pi. 1.3 f. 85. — Sard. Descr. 

Cat. p. 156, pi. 18, f. 52.— J5. M. Cat. D'Orh. Moll. p. 82, 

no. 733.— a B. Ad. Fan. Shells, p 259, no. 418. 
Compare Area Americana, D'Orh. (uon Gray,) B. M. Cat. 

D'Orh. JIoll. p. 80, no. 714 (Brazils) : B. M. Cat. Citha Moll. 

p. 43, no. 521. — ? = A. imbricata, Briig. (Jamaica, C. B. Ad. ; 

Natal, B. M.) — A very similar, perhaps identical species is 

from Australia, Jukes. 

Shell greatly resembling the Enropsean B. tetragona, but dif- 
fering from it as follows. Epidermis in B. tetragona hairy, 
even on the angular ridge ; in B. mutabilis sublamellose, as in 
B. Paciiica, with the lamellar portions gill-like. Ligament in 
B. tetragona scarcely shewing over the area, but with numer- 
ous diamonds between the umbos ; in B. mutabilis darkly 
diffused over the whole area, with or without one or two dia- 
monds at the imibos. Teeth in B. mutabilis very numei'ous, 
as in B. Pacifica ; in B. tetragona larger and fewer, somewhat 
remote. Posterior portion in B. mutabilis strongly ribbed ; in 
B. tetragona, like the rest of the shell. It is distinguished from 
the young of B. Pacifica, which it very much resembles in 
form, by the jjosterior ribs and the epidermal ridge along the 
posterior angle. Pedal gape generally large. In young shells 
the structure vmder the glass is very beautiful. I am unable 
to find any constant character by which the West Indian 
specimens can be separated from it, though the shape some- 
what differs ; and the smaller ribs ai'e more imbricated. The 
same form is from Natal, B. M. Among the best characters to 
distinguish Byssoarks are the form and nature of the ligament, 
the hinge teeth, and the epidci^mis. The markings and outline, 
as well as the inter-umbonal space, often vary considei'ably 
in the same species. The more constant characters are how- 
ever often overlooked in descriptions. Long. "8, lat. 1'35, 
alt. -72. 

Hab. — Isle of Plata, under stones, Cuming. — Eciiador, D Orb- 
igny. — Panama and Taboga ; not imcommon uuder stones 
and in the crevices of rocks, near low water mark ; C. B. 
Adams. — jMazatlan ; rare : L'pool Col. 

Tablet 649 contains 7 specimens differing in age and shape. 



140 MAZATLAN BIVALVES 

191. Byssoaeca fcsca, Brug. 

Area fusca, Brug. Did. no. 10. — D'Avila, Cat. vol. i. pi. 7, 

f. ^.—Uncz/cl. pi. 308, f. o. — Dillio. Cat. vol. i. p. 231, 

no. 14. — Lam. An. s. Vert. vol. vi. p. 466, no. 14. — Bve. 

Conch. Ic. pi. 12, f. 82.-5. M. Cat. Cuba Moll. p. 43, no. 523. 
Area barbata, var. Gmel. p. 3307. — Schrot. Einl. vol. iii. p. 279, 

no. 2.— List. Conch, pi. 231, f. Qo.— Gualt. Test. pi. 90, f. B.— 

Chemn. Conch, vol. vii. pi. 54, f. 534. 
Area bicolorata, Chemn. Conch, vol. xi. p. 243, pi. 204, f. 2007. — 

milio. Cat. vol. i. p. 230, no. 11. 

Tke presence of this well-known East Indian shell in the 
Mazatlan faima is very suspicious. I took one fresh pair, and 
Mr. Darbishire another, out of the Byssoarca box, when I first 
examined the Collection. As it is said to reach the West In- 
dies, it may linger also in the Gidf seas ; or these specimens 
may have come over on ship bottoms or drifting timber, or in 
ballast ; or they may, in some unaccounted way, have found 
an entrance into their a^jpropriate box by an accident of the 
owner's. A smaU oyster attached is not distingiushable from 
the Mazatlan species ; but this does not prove much. Long. 
1-24, lat.VQS. alt. -97. 
Sah. — Madagascar and Barbadoes, Lamarck. — "Singapore," 

abundant, P. P. C. — Barbadoes, (young valves) ,'P. P. C. — 

Cuba, Sagra. — Mazatlan : extremelj' rare ; L'pool Col. 

Tablet 650 contains the specimen I found. 

192. Byssoaeca vespeetilio, n. s. 

B.t. oblongd, coniprcssd, postice tnmidiore, expansd ; valde 
incBquilaterali, margin/bus subrotandatis, hiatii ^jerf/s modico, 
margine ibi incurvo ; unibonibus subapprcssis, ligamento loiigo, 
angusto, aniice hrcvi ; superjicic radiatim striata, striis sub- 
impressis, lineis incrementi v i x dec u s s a t i s ; rubro- 
fwscd, intus maculis duabus ab unibonibus radiantibus ; epider- 
mide lamellis concentricis, antice squaniosis, postice brevibii-s ; 
setis interstitia decurrentibu^, in lamellis i nibutis ; hue 
et illuc lineis setarum validis, longis, maxime latere postice, 
ubi semitubulares sunt; den lib us 7<rtMC? jjjarr?,?, haud 
numerosis, lineis valde incurvafis, antica brevi. 
Compare A. setigera, Bve. Broc. Zool. Sor. 1841, p. 124 ; Conch. 

Ic. pi. 14, f. 94. (Zanzibar, under stones at low water, Thorn.) 



MAZATLAN BIVALVES 



141 



This species, belonging to the group of B. barbata, setigera, 
&c., appears peculiar in tbe structure of the epidennal lameUpe, 
in which are imbedded the rather strong haii's that run down 
each of the faint radiating grooves, presenting an appearance 
like a bat's wing, or the whalebones of an lunbrella. At 
regular intervals over the surface is a row of larger hairs : 
those on the posterior part are long and stiff, curling round 
almost into a tube. Only one specimen was found in the 
boxes : a very few others obtained from a shop were probably 
from the same collection. — Long. '76, lut. 1'3, alt. "57. 
Sah. — ^Mazatlan ; extremely rare ; L'pool Col. 

Tablet 651 contains the specimen. 

193. Byssoaeca illota. Sow. 

Proc. Zool. Soc. 1833, p. 18. 

Area iWota. Rve. Conch. Jc. pi. 12, f. 78.- Hani Eec. Shells, 

pi. 18, f. 41. 
Compare A. Tabogensis, C. B. Ad. Pan. Shells, p. 262, no, 424. 

Shell, as usual, varying in form and markings ; but generally 
Avith extremely fine sharp radiating ribs, and fainter concentric 
ones decussating on a smooth surface ; the ribs being nodidous 
at the sides, and in the adult on the whole surface, when they 
become much larger. Epidermis as in B. Tabogensis, between 
pilose and lamellar, except on the ligamental area, where it is 
smooth and shining. Shape generally of the B. lactea tjpe, 
but with very close umbos, infequHateral, and flattened at the 
ventral margin. Sometimes this is considerably' incuiwed. 
Hinge teeth fevr, rather small, in two unequal, sHghtly curved 
branches. Ligament solid, adliering only at the i^osterior part, 
whence it makes a fine curl round the iimbos. A few large 
specimens were obtained from shops (probably from this col- 
lection) but only three small ones from the boxes. A rounded 
specunen measures long. '64, lat. "9, alt. "55. 

A produced sp. ,, "7, ,, 1'2, ,, "58. 

Hah. — Gulf of Nicoya, under stones, Cuming. — Do. Sinds, 

B. M. — Mazatlau ; extremelj" rare ; L'pool Col. 

Tablet 652 contains a small pair from Mazatlan; and a large 
valve from a shop. 

194. Byssoaeca geadata, Prod, c^' Sow. 

Area gradata, Zool Journ. vol. iv. p. 365. — Cfrai/ in Zool. 
Beech. Vo7j p. 152, pi. 13, f. l.—Rve. Conch. Ic. pi. 14, f. 92.~ 



142 3IAZATLAN BIVALVES 

Hani Bexcr. Cat. p. 155, pi. 18, f. 39.— i?. M. Cat. B'Orl. 
Moll. p. 81, no. 725.— C. B. Ad. Fan. Shells, p. 258, no. 416. 
= (Teste Krauss, Sudafr. Moll. p. 16) Area squamosa, Lam. 
An. s. Vert. vi. p. 474;, no. 35. — Hani. Descr. Cat. p. 158. — 
= (teste Desh.) Area Domingensis, Lam. A. s. V. vi. p. 167, 
no. 16. (differing in colour.) — = (teste Desh.) Area elatkrata, 
Defi'. A. s. V. vi. p. 478, no. 6, (fossil.) 
Compare Byssoarca divaricata Soio. Proc. Zool. Soc. 1833, 
p. 18 :— (Area d.) Bve. Conch. Lc. pi. 16, f. 108. (Annaa or 
Chain Is. attached to stones, Cuming ; W. Indies, B. ]\I.) 
Comp. Bvssoarca pusilla. Soie. Proc. Zool. Soc. 1833, p. 18 • — 
(Area p.) P. M. Cat. P'Orb. Moll. p. 81, no. 717. (Iquiqui, 
Peru, on stones at low water, Cuming ; Bolivia, Cobija, 
Peru, Arica, P' Orhigny.) 
Comp. Area douaciformis, Pve. Conch. Ic. pi. 16, f. 104 : — 
Proc. Zool. Soc. 1841, p. 125, (Mozambique Channel, in 
Madrepore, Hanlcey.) 

This species varies considerably in the fineness or coarseness 
of the cancellated markings, in the projection or otherwise of 
the posterior rib, and in the shape, which often api^roxiniates 
B. solida. and is not unfrequently greatly appressed. Liga- 
ment very narrow, solid, onl}' adhering at the i^osterior part, 
whence it makes a slight turn round the umbos, as in B. illota. 
Hinge teeth rather few, slanting, on \inequal Unes slightly 
diverging. Muscular scars prominent, glossy white, as though 
on a single plate attached to the shell. The pedal chink is 
perceptible, but very small. These characters include speci- 
mens from the W. Indies, which are luuloubtedly A. squamosa, 
Lam. also quoted by Krauss from !Xatal. If, as is probable, 
the species are identical, the Lamarckian name has priority. 
Another W. Indian species, probably A. iimbonata, A. s. v. 
p. 462, no. 5., differs in the fineness of the cancellations, and in 
the ligament which fills a central pit, as in B. solida. The 
A. pusilla of D'Orb. may be a dwarf var. of the ^lazatlan sheU, 
but the Cumingian type appears distinct. A specimen of the 
tj'pical form measures long. '47, lat. "83, alt. '38. 
Hah. — Mazatlau, Pcechcifs Voyage : — Do. rare, nestling in 
crevices of large shells ; L'pool Col. — Sta. Elena, attached 
to stones, Cuming. — Ecuador. Sta. Elena, D'Orhigny. — Sta. 
Barbara, Col. Jewitt. — Taboga ; uuder stones near low water 
mark, very rare ; C. B. Adams. — Also given from Ld. Hood's 
la. and the Marquesas. — (A. squamosa.) "N. Hollande, a 
rUe King. Mus," Lamarck. — Natal, Krauss. — (A. Domia- 



MAZATLAN BIVALVES 



143 



gensis) St. Domingo, Lamarck :— W. Indies, Bristol Mus.— 
(A. clatlirata) Fossil near Augers, Menard. 

Tablet 653 contains 6 very j-oimg pairs and 7 pairs of valves, 
extremely young, tlie smallest measuring '04 by '02, greatly 
varying in'outline. The teetb are at first very few in number, 
and the internal ridge rather prominent.— 654, a yoimg pair 
nestled, in situ, in fragment of Spondylus calcifer ; also 2 
dried byssal feet.— 655, 6 sp. young.— 656, 8 adult sp., various 
shapes. Two sp. wiU also be found in situ on Chama (tablet 441.) 



195. Byssoabca solida, Sotv. 

Proc. Zool. Soc. 1833, p. IS.— 311111. S//ii. Test. Viv. p. 186. 
Area solida, Rre. Conoh. Ic. pi. 16, f. lOQ.Sanl. Bescr. Cat. 

p. 1.55, pi. 18, f. 54.-1?. M. Cat. JD'Orh. Moll. p. 81, no. 716.— 

C B. Ad. Pan. Shelh, p. 262, no. 423. 

This unpretending species greatly resembles our B. lactea, 
and a similar W. Indian species ; but differs from each by 
well marked characters. In this, the ligament is in a very 
narrow rhombus ; in B. lactea, in a broad one ; in the West 
Indian it fills nearly the whole area. In B. solida, the hinge 
teeth are nearly or quite obsolete within the ligament, even in 
young shells ; in the other two species the teeth are in an 
uniuteiTupted line. The surface also in B. solida is generally 
decussated with concentric tubercles ; but this character is 
not constant. Shape either flattened and produced, or short 
and much swollen. Epidermis brown, thin. Byssal foot 
extremely thin ; ventral margin not perceptibly gaping. — 
A finely grown specimen measvu'es lour/. "35, led. '56, alt. '28. 
A swollen sp. „ ,, '34, „ '47, „ '43. 

The largest sp. „ „ ■46, „ -67, „ '46. 

Hah—VnAer stones at Payta, Peru, Cuming, D'Orhigrty.— 

Panama and Taboga ; not uncommon under stones near low 

water mark ; C. B. ylc^a«t.9.— Mazatlau ; not uncommon ; 

L']}ool Col. 

Tablet 657 contains 5 pairs and 1 valve very young, the 
latter '03 across ; one pair is strongly decussated. — 658, 5 sp. 
scarcely decussated. — 659, 3 do. flat growth.— 660, 3 do. with 
former margins projecting. — 661, 3 do. swollen. — 662, 3 do. 
very much swollen, umbos distant. — 663, 3 sp. shewing the 
interior. 



141 MAZATLAK BIA'ALTES 

Genus PECTUNCULUS, Lam* 

196. Pectuxcultjs in^qualis, Sow. 

Pi'oc. Zool. Soc. 1832, pt. ii. p. 196 : [non Gra?/ in Beech. Toy. 

p. 152, pi. 42, f. 3 : (y. Rve. iu P. Z. S. 1843, p. 79 ;) nee 

Krauss, Sudafr. Moll. p. 18.] — Saul. Descr. Cat. p. 166. — 

Rve. Conch. Ic. pi. 4, f. 16. 

= P. Peetiniformis, Wood Suppl. pi. 2, f. 11, non Lam. (teste 

Hani.) 
? = P. assimilis. Sow. Proc. Zool. Soc. 1832, pt. ii. p. 196.— ilf«^/. 
S//)i. Test. Viv. p. 189.— i?2;e. Conch. Ic. pi. 4. f. lo.—B. M. 
Cat. B'Orb. Moll. p. 80. no.712.—C. JB. Ad. Pan. Shells, 
p. 256, no. 411. — Sa7il. Descr. Cat. p. 167, note. 
Only two specimens haruig been found adult of tkis ex- 
tremely beautiful shell, no opportuuitj- existed for ascertaining 
its power of variation ; but C. B. Ad. thus remarks of P. 
assimilis, "In respect of colouring (no two being alike) the 
species does not appear to be well distinguished from P. 
ingequahs : nor is the distinction in sculpture much more con- 
stant." Surface of the shell with a variable, smaU number of 
ribs, covered, as well as the interstices, with fine ribs decussa- 
ted in the "strung fig" pattern. Margin most beautifully 
crenated by each ; interior surface covered with fine lines ; 
anterior part short, ligament subtrimcated. A veiy young 
valve, '04 across, displays 3 teeth on each side, with the larger 
ribs only developed outside and decussated : ligament in a pit 
as in Limopsis. Long. 1'33, lat. 1'31, alt. '9. 
Hah. — Bay of Panama and Real Llejos ; in sandy mud, 10 fm. ; 
Cuminy. — Mazatlan ; extremely rare ; L'pool Col, — (P. as- 
simdis) Puerto Portrero, Bay of Guaj-aqiiil ; in sandy mud 
and gravel 8-12 fm. ; Ciuning. — Ecuador, Guayaquil, D'Orb- 
igny. — Panama ; under stones, in calcareous gravel, between 
one-quarter tide and low water mark, rare ; C. B. Adams. — 
Mazatlan, Lieut. Green. 

Tablet 664 contains the smallest valve. — 665, the finest 
specimen. 

197. Pectujtculus ? multicostattjs, Sow. 
Proc. Zool. Soc. 1832, 'pt. ii. p. ido.—Pre. Conch. Ic. pi. 5. 
f. 26.— Hani. Descr. Cat. p. 165, pi. 19, f. 26.— B. M. Cat. 
D Orb. Moll. p. 80, no. 711. 

• " The first name for these shells is Axinsei, Poll. If Pectnnculus, Lam. (aot 
Adanson) is to be used, it should be limited to the ribbed species." A. Adam*, ms. 



MAZATLAN BIVALVES 145 

Tablet 666 contains a young valve, '07 across, which may- 
belong to this species. It is however white, with about 30 
rounded ribs ; inside with a remarkably straight hinge line. 
Hab. — Ecuador, Guayaquil, UOrhigny, — ? Mazatlan ; 1 valve, 

off Chama ; Upool Col. 



Family NUCULID^. 

Genus jSTUCULA, Lam. 
Xucula, Lam. 1801.— Polydonta, Mccjerle, 1811. 

198. NUCULA ? EXIGCA, Soxu. 

Proc. Zool. Soc. 1833, p. \d9,.~Mull. Srjn. Test. Viv. p. 192.— 
Sow. Conoh. III. no. 31, pi. 16, f. 24i.—Eanl. Bescr. Cat. 
p. 172.— i?. M. Cat. BOrh. Moll. p. 79, no. 701.— C. B. Ad. 
Pan. Shells, p. 255, no. 409. 

Tablet G67 contains one very young valve, '03 across, which 
may belong to this species. The concentric grooves are just 
forming at the margin. 

Sab. — Bay of Caraceas, in sandy mud, 9 fm. ; Cuming, IfOrh- 
«5"*y-— Panama, 1 valve, C. B. ^f^aws.— Mazatlan ; 1 valve 
off Spondylus calcifer ; L'pool Col. 

Genus LEDA, Solium. 

199. Leda PElenensis, Sovo. 

Nucula Elenensis, Proc. Zool. Soc. 1832, p. \m.—Miill. Si/n. 
Test. Viv. p. 19i._5foro. Conch. III. no. 19 pi. 15, f. U.—Rve. 
Conch. Syst. pi. 85, f. U.—Hanl. Descr. Cat. p. 169.— 
C. B. Ad. Pan. Shells, p. 251, no. 408. 

Leda Elenensis, B. M. Cat. BOrh. Moll. p. 63, no. 554. 
Tablet 668 contains a minute valve, '06 by '04, which may 

belong to this species. Transparent, concentrically grooved, 

but (as in C. B. Adams' specimens) margin not crenulated. 

Hah. — St. Elena, in sandy mud, 6 fm. Cuming, B'Orhigny. — 
Panama, rare, C. B. Adams.— Hl^z^Wacsx ; 2 valves off Spon- 
dylus calcifer ; L'pool Col. 

Feb. 1856. 



146 mazatlan bivalves 

Family AVICULID^. 

Genus PINNA Linn. 

The remarkable similarit;\- in form between the young shells 
of Isognomon and those of this genus, confirms the opinion of 
Dr. AV. B. Carpenter (Br. Assoc. Eep. 1833, p. 20,) and, Prof. 
E. Forbes (Br. Moll. vol. ii. p. 250,) that it ranks in the present 
family. An abundance of large Pinnae, sent in the Liverpool 
Col., were imfortimatelj' sold off at once to the keeper of a 
tea garden, where they may be seen built up into the walls, 
and too much disfigiu'ed to allow of the species being identi- 
fied. To add to the confusion, an importation of large Piunfe 
from New Guinea having reached Liverpool at the same tune, 
were mixed with them, both in the shop, and in the garden 
walls ; and some have found their way into collections as 
though from ^lazatlan. A similar confusion seems to have 
attended the Pinnae sold in Loudon with the Havre Col., on 
some of which the attached Ycrmetida?, corals, &.c. clearly 
prove that they came from far distant seas. The three follow- 
ing species are all that can be quoted with certainty as having 
been found in the JMazatlan boxes. Another species, hke P. 
maura, but remarkable for its extreme breadth and thickness 
and for the shape of the anterior muscular impression wliich 
displays a series of ripples, was sent in the S. TV'. Mexican 
collection. Some species of this genus alter considerably in 
the shape of the posterior extremity, as they attain maturity. 
The measurements are taken as in Mytilidae. 

200. Pinna mauea, Soic. 

Proc. Zool. Soc. 1835, p. S-L—JIanl. Descr. Cat p. 255.— 

C. B. Ad. Pan. Shells, p. 250, no. 395. 

Adolescent shell dark brown, with about 18 rows of irregu- 
lar scales, here and iherc almost tubular ; dark brown ; pos- 
terior end produced, margin rather straight, ventral edge 
smooth, slightly inflated ; hinge line incurved near the umbos : 
anterior impression bilobed. Long. 8'5, lat. •1'5, alt. 1"58. 
Hah. — Panama, in muddy banks, Cuming, — Do^ extremely 

rare, C. B. Adams. — Mazatlau ; probably common, as Lieut. 

Belcher (Zool. Journ. vol. iv. p. 362) speaks of the large and 

dangerous shoals of Pinntc in the harbour, which cut boats 

with their sharp edges ; L'pool Col. 

Tablet 669 contains one of the verj- few specimens saved. 



MAZATLAN BIVALA'ES 147 

2<„U. Pinna lanceolata, Sotv. , 

Proc. Zool. Soc. 1835, p. %l.—Hanl. Bescr. Cat. p. 256. 

Shell, wheu extremely young, nearly smooth, -nith a very 
long liinge line, but much shortened posteriorly : gradually 
developing radiating ridges. 8-10 in the adult, which become 
furnished with regular rows of long, almost tubular spines, 
extremely thin, light horny brown, ventral part swollen and 
smooth, with the margin rounding off posteriorly till it meets 
the dorsal line at right angles. Hinge line often incurved 
near the umbos. The smallest specimen found is 1' 75 long; 
the largest, long. 4"2, Idt. 1"7, alt. (with spines "77, without) 
•28. 
Hab. — Puerto Portrero ; in sandy mud, 13 fm. ; Cuming. — 

Mazatlan ; in fine sand, not imcommon ; L'pool Col. 

Tablet 670 contains 3 sp. very young.— 671, 2 do. older, with 
few rows of spines develoi)cd. — 672, 4 do. orclinarj' state. — 673, 
2 do. crowded with tubercles. — 674, 1 do. distorted growth. 

202. Pinna Peugosa, Sow. 

Proc. Zool. Soc. 1835, p. S4>.Sanl. Descr. Cat. p. 256. 
P. rugosa, jun., teste Cuming. 

About a score of specimens were found with P. lanceolata, 
presenting the following characters. Shell extremely thin, 
verj^ light horn coloured, transparent, glossy, with the cell- 
structure so large as to be visible to the naked eye, giving a 
peculiar texture to the surface ; very long and narrow, ventral 
part not inflated ; with about 6 strong ribs, traceable from 
the umbos, and scarcely ceasing at the ventral part, armed 
with large, distant, nearly tubular spines. The smallest speci- 
men is 1"9 long; the largest, long. 4'8, lat. 2', alt. (with 
spines 1"2, without) '6^4. 
Hah. — Isle of Eey, Bay of Panama, on sand banks, Cuming. — 

? Mazatlan ; very rare ; L'pool Col. 

Tablet 675 contains the smallest and the largest specimens. 

Genus AVICULA, Klein. 

Avicula, Klein, 1753 -.—Brug. 1789 -.—Lam. 1799. 
Pteria, Scopoli, 1777 -.—Gray, 1847. 



148 MAZATLAN BIVALVES 

203. AviCULA STEENA, Go^lld. 

Proc. Bost. Soc. Nat. Risf. Nov. 1851, vol. iv. p. 93 -.—Mex. Sf 
Cal. Shells, p. 31, pi. 16, f. 7.— C. B. Ad. Pan. Shells, p. 250, 
no. 392. 

Aviciila Atlautica, Menke, Zeit.f. Mai. 1847, p. 187, no. 45 ; 
non Lam. 

"Has the general ai^pearance of A. semisagitta, Lam. but 
the wing is less oblique, and curves directly into the cauda 
Avithout any sinus ; the byssal sinus is deeper and much more 
acute, making a trapezoidal auricle. It most nearly resembles 
a Florida species ; but in that the bj^ssal angle is obtuse, the 
auricle triangular, and the cauda shorter." Gould.* The hinge 
line is generally extremely long, but sometimes so short that 
the anterior are rather larger than the posterior auricles. Shell 
very ina?quivalve. Outer layer of shell dark chocolate, rarely 
slightly rayed with white. Surface almost smooth, with very 
fine concentric lines of gi'owth. Epidermis in fine strongly ser- 
rated, closely folded lamina?. Hinge teeth, card. 2-1, lat. 1-1. 
The pallial line is traceable from the large bdobed i)osterior 
adductor to the small anterior, situated just below the cardinal 
teeth. A peculiar species of Balanus is commonly foimd on 
this shell, and on the related W. Indian species. Many speci- 
mens of Discoporaja intricata, and eggs of Gasteropods were 
also found attached. The smallest sp. is '05 in length ; the lar- 
gest 1"24. A normal sp. measures long. "98, lat. 2 "5, alt. '42. 

One with short hinge „ 1'23, ,, 1"7, „ "59. 

Hab. — Panama, Col. Jeicetf, — Do. ; very rare, attached to a 
small species of Gorgonia, at the low water mark of the 
spring tides ; C. B. Adams. — Mazatlan ; not uncommon ; 
TJpool Col. 

Tablet 676 contains a minute valve, "05 long, with the lateral 
tooth conspicuous. — 677, 7 young pairs of diflerent sizes, (one 
with egg cases) and a valve shewing spotted umbo. — 678, 4 sp. 
adult. — 679, 3 do. shewing interior.— 680, 4 sp. different ages, 
with the 'ear,' 'wing' or 'taU' very much shortened; the 
larger with Discopora;a intricata. 



* Dr. Gould's 'wing]' appears to be the body of tlie shell ; his 'cauda' what 
is by others called the wing or the ear. 



MAZATLAN BIVALVES 14fl 

Subgenus MAEGAEITIPHORA, Meg. 
Megerle v. MiUilfeld, 1811.— Meleagrina, Lam. 1819. 

204. Maegaeitiphoea Mazatlanica, Hani. 
Meleagrina Mazatlanica, Hani. Bee. Shells, pi. 2-i, f. 40. 

JSTo synonjTns of the Pearl-oyster are given, as the question 
of the specific identity of the local tj^e?, is not yet settled. 
The Gulf of California used to be celebrated for its pearl 
fishery, but it appears to have been exhausted, and very few 
oysters have been brought of late years. The specimens from 
S. W. Mexico appeared to belong to the Panama type, being 
small, produced and of a purplish brown. Of this shell in 1851 
a single vessel brought 340 tons to Liverpool (T. C. Archer.) 
The other local types are the silver-lipped from the Society 
Is. and the black-lipped from Manilla. Which of these is the 
true M. margaritifera of Lam. has not yet been settled. In 
Hani. Descr. Cat. are also quoted, p. 264, M. radiata from the 
? W. Indies, and M. albina from Australia. Mr. Nuttall found 
a pretty little species, quite distinct from the yoimg of M. 
margaritifera, at the Sandwich Is. Pearl-oysters are also found 
at Madagascar, Persian Gulf, Ceylon, Swan Eiver,_&c. Very 
few specimens were sent in the Mazatlan collection, and of 
these only the young ones were preserved. Shell in that state 
transverse, not produced ventraUy, one valve only pierced for 
the byssus, swollen at that part, else flat, spreading ; with 
closely set overlapping laminse, extremely thin, produced 
into foliations or flat spines ; inside silvery white, nacre bor- 
dered with green, margin broad, of a light tortoiseshell colour. 
Long. 3'55, lat. 4"05, alt. 1'27, (jun.) 
Hah. — Mazatlan ; very rare ; L'pool Sf Havre Coll. 

Tablet 681 contains a very young valve. "05 across, of nearly 
normal shape, known from the young of the neighbouring 
species by the enormous size of the prismatic cells. — 682, the 
specimen above measured. 

Genus ISOGNOMON, Klein. 

Isognomon, Klein, 1753 : — Dhr. in Moll. Gruin. 
Melina, Betz, 1788, Di.s-s. p. 28 -.—Schmn. 1817. 
Perna, Briig. 1792 -.—Lam. 1801 :— (non Betz.) 
Sutura, Meg. v. Miihlf. 1811. Entw. p. 65. 



150 MAZATLAN BIVALVES 

Some ooafusiou lias arisen in this genus as in Pinna from a 
large number of the Malleus-shaped species from New Guinea 
having been brought at the same time with the Mazatlan 
collection, and having found their way into musexims as though 
from this locality. The variations of form in these were most 
extraordinarj'. 

205. IsoGXoiroN CnEJiNixziAxrji, UOrb. 

Perna Chemnitziana, UOrl. Saqra, Cuba, vol. ii. p. 346.— 
B. 21. Cat p. 46, no. 547. 

Perna flexuosa, Soic. ms. in Coll. Kellett, Mus. Pract. Geol : — 
(do. Panama, Lieut. Wood, Bristol Mus.) 

= Perna, sp. ind. fa), C. B. Ad. Pan. Shells, p. 250, no. 393. 

Comp. Isognomon Perna, Linn, in Lhr. Moll. Guin. no. 116, 
pi. 8, f. 7-10: = (teste Dkr.J Ostrea perna, List. Conch. Tab. 
199, f. ■ii.— Chemn. Conch. Cab. vol. vii. p. 252, pi. 59, f. 580.— 
Schroet. Einl. vol. iii. pi. 9, f. 5. — Lam. vii. p. 78, Perna 
vulsella, excl. var. b. [Common at St. Vincent and Loander, 
Tarns. "'Omnia plane respondent iis, qua? ex AntiDis insulis 
et ex America centrali originem ducunt. = sine dubio, Concha 
semiaurita, var. Chcmn. vol. vii. f. 580. (?f. 579, = P. radiata, 
Anton Verz. p. 17).] 'Sovl O. semiaurita Schroet. loc. cit. f. 6." 

The Mazatlan shells arc cei'tainly the P. flexuosa of Soiv. I 
cannot detect the slightest specific difference between these, 
and specimens collected at St. Vincent's (W. I.) by Dr. W. B. 
"Carpenter. These are the P. Chemnitziana of D'Orb.. which 
name I have therefore adopted till the date of Sow.'s is known. 
Whether it is the shell quoted by Dh: from Central America 
and W. I. as well as from Guinea, cannot in so variable a 
genus be decided only from descriptions and figures. The 
Mazatlan shells are small, very variable in shape, normally 
suborbicular, but generallj- produced. Shell with concentric 
irregidar ridges of growth, but without sculpture on either 
valve. Beaks much produced, terminal; byssal portion'incur- 
ved ; ventral part flattened. Muscular impression extremely 
large : ligameutal pits deep, numerous and regidar. Colour 
ash, more or less stained with purple, especially at the ventral 
part, often very rich. The shell in its first appearance seema 
to be C^Tcna-shaped, then like an inflated Anodon, then like 
Inoceramus, then for some time like a broad Pinna ; then it 
gradually developes its true form, as far as is consistent with 
the crevice in which it has taken up its abode. One pit is de- 



MAZATIAN BIVALYES 151 

veloped (as a sinking in the otlierwise Avicula-shaped ligament) 
at a very early stage ; afterwards a second, and so onwards. 
TLe prismatic structure is not apparent at first, but soon 
develops at tlie ventral portion in ceUs intennediate in size 
between tbosc of Avicula sterna and M. Mazatlanica, making 
the transparent young valves verj' beautiful objects. Tke size 
of the shell when the ligament pits appear, varies greatly ; and 
the rapidity with which one individual will completely alter 
its form is most extraordinary. The largest valve measures "03 
across ; an enormous specimen, long. 2'1, lat. V, alt. '5. 
One of normal shape „ „ 1*, „ "7, ,, "24. 

A produced one „ „ 1'53, „ '51,,, '16. 

Hab. — Cuba, Sagra. — St. Vincent's, W. I.. W. B. Carpenter. — 
Conchagua, Sinds. — Panama, Lieut. Wood. — Mazatlan ; not 
uncommon in crevices of large shells, affixed by a short 
strong byssus ; L'pool Col. — (Perna a.) Panama ; common 
under stones and in crevices of rocks at Ioav water mark ; 
C. B. Adams. — La Paz ; Lieut. G7'een. 

Tablet 683 contains 7 pairs of valves, extremely young. — 
684, 4 pairs and 2 pairs of valves, a stage older. — 685, 6 pairs 
and 2 closed hinges, young.— 686, 3 pairs adolescent. — 687, 4 
pairs adult, greatly varying in shape. — 688, 2 sp. in situ, in 
crevices of Patella Mexicana, and in dead Balanus off do. 

206. IsoGNOMON Janus, 71. s. 

I. t. rhomboided, tenui, planatd, pallida ; valvd inferiori 
l(Bvi, stcperiori costis gracillimis, interdum obsoletis, testd juni- 
ore spinis semitubiilis imbricatd ; haud aurita, angulo ad 
umbones acuto ; marginibtcs ant. et post, suhparallelis, subrectis : 
cardine Ugamento ut in Aviculd longo,fossibus x>erpaucis, mini- 
mis, irrcgularitev dispositis ; imp. muse, haud magna. 

Shell known from all the fonus of I. Chemuitzii by its regu- 
lar lozenge shape without ears, thin texture without concentric 
ridges, light colour, aud by the sculpture of the valves of 
which the \mder is smooth, the upper ornamented with fine 
radiating stria?, which in the young shell are crowded with 
semitubular imbricated spines. The hinge line is narrow, 
without pits when young, when adult with a very- few (4) small 
ones at unequal distances. Muscvdar impression much smaller 
than in I. Chemuitzii. The youngest shells are very inajqui- 
valve, and display capped umbos, consisting of Venus-shaped 



152 



MAZATLAy BIVALVES 



fry. It probably resembles P. costellata, Conr. from the 
Sandwich Is., but that is described as having both beaks alike. 
The smallest specimen is ' (I5 in length ; the largest, long, (the 
diagonal of the lozenge) 1"12, lat. "68, alt. '17. 
Hab. — Mazatlan ; on I. Chemnitzii and Spondyliis calcifer, 
extremely rare : L'pool Col. 

Tablet 689 contains 1 pair and 2 valves, very young. — 690, 
the most characteristic specimen, in situ. 

Family PECTINID^. 

Genus PECTE:^, Miill. 

Of this (in most places) abundant genus only 3 very small 
valves were found. The neighbouring genus Lima was alto- 
gether absent. 

207. Pecten cieculaeis, Soiv. 

Proc. Zool. Sac. 1835, p. 110.— mod. Descr. Cat. p. 271. 

Dull ash, variegated with chocolate ; ears very large ; inter- 
stices near the umbo finely decussated. The opposite valves 
differ in sculpture. — Long. "28, lat. "26, alt. '12. 
Sah. — Guaymas ; in sandy mud, 7 fm. ; Col. Cuming. — St. 

Vincent's [?] Hanley. — Mazatlan ; extremely rare : L'pool 

Col. 

Tablet 691 contains the only valve I found. 

Family SPONDYLID^. 
Genus SPONDYLUS, Linn. 

208. Spondylus calcifee, n. s. 

S. t. maxima, ponderosd, solidd, plerumque orhiculari ; rubra- 
purpiireo ; valvA superiore cost is minimis aculeat is 
creberrimis tectd, hue et illuc costis irregularibns squamosis ; 
squamis curtis, ad basim arciiatis, supra foliatis ; valvd infer- 
lore plerumque fuU at d ; area I igamenti magna, ligamento haud 
tecto ; intus subnacred, limbo lato toto purpure o, seu 
nonnumquam Jlavesco-rubente ; inargine extremo ere- 
be r rime et m i nut e c re nulat o ; dentibus validis ; fossa 
ligamenti canalibus 2-6 parallelis, decussatis ; mu^c. imp. sub' 
orbiculari, magna. 



MAZATLAN BIVALVES 153 

Spondylus Lamarckii, Hanley ms. ; et ibi supra, passim : non 

Sow. 
Spondylus ? Lamarckii, C. B. Ad. Fan. Shells, p. 247, no 385. 
This species has been quoted in the earlier pages of the 
foregoing Catalogue \mder the name of S. Lamarckii. The 
type of S. Lamarckii, however, is a very different shell, more 
like S. ducalis, of produced shape, with edges interlocking 
as in Pecten, and very coarsely crenated in addition -.margin 
dark brownish purple, area not divided, teeth and ligament 
small. This shell most resembles S. dubius, Brod. Proc. Zool. 
Soc. 1833, p. 4: = S. pictorum, var. teste .Sow. in TJies. Conch. 
It differs however in the very crowded rows of prickles over 
the surface ; in the character of the spines, which are arcuated 
in S. dubius, spreading above in S. calcifer ; and in the interior 
crenations which are very small in this shell, and scarcely 
seen m the adult. Mr. Cuming first saw the species, on a 
small island in the Bay of Panama, where the natives dive for 
them, to biirn into lime ; of which they must furnish an excel- 
lent supply, being solid, not in chambers as in most large 
Spondyli. He broke up many specimens for their contents, 
but they were too cumbrous for removal, ''some of them being 
more than a foot high and a foot broad." The adidt valves are 
known at once by the "broad deep red purple finely wrinkled 
limb of the otherwise white interior," C. B. Ad. In its 
younger stages however, it occasionally displays a salmon 
colour or even the orange tint of S. dubius. The species was 
not seen by INIr. Sowerby in preparing his monograph ; but, 
Mr. J. S. jun., having directed my attention to many of the 
above characters, was satisfied of its distinctness. 

The Mazatlan shells, when young enough to display their 
characters, are attached by a portion of the lower valve to 
rocks, large Pinnaj, &c. The valve develops irregular folia- 
tions, to aid the adherence. The ligament area is long, rather 
slanting, and with the groove open to the summit. The upper 
valve and the unattached poi-tion of the lower are very finely 
radiatelj'' striated, the striff being granulose, or developing 
short prickles. At very irrregidar intervals, there are very 
irregular and gcncrallj'' ill-developed ribs, which are here and 
there armed with vaulted scales, not large even in the young 
shell. The white, rather nacreous interior displays a broad mar- 
ginal band, generally purple in the adult, very rarely reddish 
orange, which is the colour of the young shell. This margin is 
finely crenated. The muscular sear is very large, irregularly 



154 MAZATLAX BIVALVES 

suborbicular. The ligament has a variable number of longi- 
tudinal grooves, each broken up into portions like a necklace. 
The shell is generally suborbicular and massive (sometimes 
6 in. thick, Hani.), and affords a safe asylum not only for 
the ordinary boring and nestHng bivalves, but for numerous 
small Gasteropods, especially Coeca, Odostomidt'e, VitrineUa;, 
Naricaj, &c., which establish themselves in emptj^ bun-ows 
and in the gaUeries formed by numerous boring worms, in the 
coloured portion of the sheU. The possession of a single valve 
therefore is quite a treasure to a patient conchologist ; as, after 
working out the borers, he will find a plentiful supply of species 
among the debris. Most of the small shells described in this 
Catalogue were thus taken from the large Chama^ and Spon- 
dyli, by carefully passing the sheU-washiugs through a fine 
wire sieve, and examining the remainder under the glass. x\. 
single specimen of Spondylus was found to contain the follow- 
ing species : — Parapholas calva, Gastrochfena ovata and trim- 
cata, Petricola robusta, EupeUaria linguafeUs, Saxicava arctica, 
Sphasnia fragilis, Cumingia 3 sp., TeUina 2 sp., Veneridte 5 sp., 
Gouldia Pacifica and varians, Circe margarita, Cardita CaU- 
fornica, Cardium 2 s^)., Lucina, 2 sp., Kellia suborbiculai'is, 
Lepton 2 sp., Mytilus 2 sp., Crenella, Septifer, Lithophagus 
aristatus and plumula, Byssoarca gradata and solida, Chama, 
Isognomou, Avicula, Anomia, Discina Cumingii, Bullida^ 2 sp., 
Chiton, Patella 2 sp., Siphonaria (2 varieties), Crepidula 2 sp., 
Fissurella 2 sp., Hipponyx, Vermetus 2 sp., Torinia, Trochus, 
Narica, A^'itrineUa 6 sp., Fossar, Littorina 2 sp., Eissoidfe 5 sp., 
JeiFreysia, Cerithiada; 5 sp., Odostomia 6 sp., Chemnitzia 3 sj)., 
Eulima 2 sp., Scalaria, Cacum 5 sj)., Columbella 5 sp., Nassa, 
and MargiueUa 2 sp : in all 103 species, of which 7 only were 
fragmentary. It is impossible to say how many more might 
have been rescued from oblivion, had not the original pur- 
chaser of the collection immediately sold ofi" almost all the 
lai'ge shells to the keeper of a tea garden connected with a 
public house near Manchester, where they ma.y be seen, the 
Pinna; built up into grottos, and the Spondyli and large 
Patella; arranged alternately round the skirting board of his 
"Museum." These shells were carefully washed, by the publi- 
can's servant, and the precious dirt thrown away. Mr. Hanley 
was more fortunate, and obtained many fine specimens from 
the Havre Col. The largest spccunen I obtained measures 
loiui.l', lat.1', ali.G'Q. The measurement was however taken 
after the sheU had been decorticated to obtain the borers. 



MAZATLAN BIVALVES 165 

Sab. — Bay of Panama, in a few fathoms of water, Cuming ; 

C. B. Adams. — La Paz ; Lieut. Green. — Mazatlan ; not 

uncommon ; L'pool Sf Savre Coll. 

Tablet 692 contains a young specimen perhaps belonging 
to this species, but diflering from the rest in having the Uga- 
mental groove closed, and the scaly processes larger and more 
spathulate : /owf/. 2'3. 

Tablet 693 contains a very 5^oung, ^highly coloured valve, 
"22 across. 

Tablet 694 contains a young sp. from Pinna, with Ostreae, 
Vermetidse, &c. attached : long. 4". 

Tablet 695 contains a finely grown adult sp., with Verme- 
tida;, Chama &c. attached. 

Tablet 696 contains a sp. presented by F. Bacon, Esq.. 
displaying the interior. The outside contains burrows of 
Parapholas calva, Gastrochsna ovata and truncata, Lithopha- 
gus aristatus and phmiula, &c. Two Pholads remain in situ, 
having forced themselves against the interior of the shell. 

Tablet 697 contains a fragment of an attached valve, 2 ' 5 in. 
thick, with numerous burrows, displaying the white marble- 
like interior portion, and the coloured exterior bored by 
worms. — 698, 2 fragments displaying the colour layers. — 699, a 
fragment exhibiting the orange red colour. 

209. ? Spondylits , sp. ind. 

Tablet 700 contains a fragment with very large flattened 
tubercular knobs. 
Sab. — Mazatlan ; in Chama washings ; L'pool Col. 

Genus PLICATULA, Lam. 

210. Plicatula penicillata, n. s. 

P. t. albd, brunneo scepe tenue pcnielllatd, elongatd, hand 
valde eostatd, margine plerumque plicatd ; dcntibus cardinali- 
bus elongatis, rugosis, externis magnis valde exta)ttibus ; internis 
angicstis, liguinentum minimum tubulatum amplectentibus ; cica- 
trice musculari subcimulari seu suhovali. 

Plicatula dubia, var., Sow. ms. in Mus. Cuming. 

A small specimen in Mr. Cuming's collection did not present 
sufficiently marked characters, in the judgment of Mr. Sowerby, 



156 MAZATLAN BIVALVES 

to separate it from the aberrant sijocies from Ld. Hood's Island. 
The Mazatlan specimens are however distinct both m colour 
and habit of growth. A very young valve ' 15 across is not 
plicated : a larger flat specimen on Crepidula is ribbed, but 
scarcely plaited at the margin : a still larger one is but very 
indistinctly ribbed. A swollen, short specimen, grown on a 
spine of Murex nigritus, is rather strouglj^ plicated ; while the 
largest, in Mr. Darbishire's collection, grown between two 
folds of Chama, scarcely displaj's crenations, except near the 
hinge. The finest grOAvn specimen displays the following 
characters : margin scarcely plicate, internally finely crenated 
on each side of the hinge : a deep hollow in each valve running 
up inside the umbos : central teeth (on the attached valve) 
joined together for more than half their height, holding the lig- 
ament, which is extremely small, tubidar, only exposed at the 
extremities, and running up to the umbos, though not exposed 
(or scarcely covered) as in Spondylus, but nearer the interior 
of the shell. In the free valve, the ligamental tube rises up, 
separating the pits of the inner teeth. In this specimen the 
muscular scar is almost round ; in another, rather oval. The 
valves are held together by the interlocking of the large rugose 
teeth. No other species is described from the West American 
coast. Mr. Darbishii-e's specimen measures, lonj. 1"2, lat. '6, 
alt. -38. 
Sah. — Bay of Fonseca, Cuminc). — Mazatlan; extremelj' rare, 

on shells ; L'^ool Col. 

Tablet 701 contains the pair off Murex nigritus'; the young 
flat valve ; and the finest specmien, off Crepidula acideata, 
(white var.) 

Family OSTEEIDiE. 

Genus OSTREA, Linn. 

The usual discriminating marks between species are of little 
value in this genus. Neither the shape, amount of adherence, 
sculpture, character of the hinge, colour, direction of the 
umbos, dcnticulation or plication of the margin, nor even the 
shape of the niuscidar impression, afford unvarying characters. 
Geographical distribiitiou also is not of much help, the same 
forms appearing in widely distant seas. The study of the 
young shells dc^es not, as it is wont, bring fresh light ; very 
widely separated forms being scarcely distinguishable in early 



ilAZATLAN BIVALVES 157 

stages. The prismatic external layer, in rather large cells, is 
often beautifully apparent at this period. The naturalist has 
to rely on a balance of characters and the general habit of 
growth ; and even in these is liable to great error, unless he 
judge from a comparison of large series of specimens. Those 
from Mazatlan were nimierous enough to confuse, not to help ; 
and therefore the following descriptions wiU need verification. 

211. OsTBEA lEiDESCENS, Gray. 

Gray, ms. B. M. — Hani. Conch. Misc. Ostrea, pi. 2, f. 6, 7. 
Ostrea sp. ind. h, C. B. Ad. Fan. Shells, p. 245, no. 381. 
Compare O. prismatica, Gray, Ann. Phil. vol. xxv. 1825. 
Comp. O. spatliulata, Lam. An. s.- Vert. vol. vii. p. 225, no. 16. 
Comp. jun. O. margaritacea. Lam. loc. cit. p. 228, no. 26. 
Comp. jun. O. iEciuatoriahs, D'Orh. B. M. Cat. Moll. p. 88, 

no. 776: — ? + (teste Gray) O. Puelchana, D'Orh. loc. cit. 

p. 87, no. 775. 
Jun. ? = Ostrea rufa (pars), Gould ms,. (California.) 

As it is very doubtful whether the M azatlan shells belong 
to either of the imperfectly characterized Lamarckian species, 
and as they certainly belong to the O. iridescens of Gray, 
just published by Ilanley, I have adopted the latter name. It 
is recognized pretty distinctly (for an oyster) by its prolonged 
rectangular shape, long square hinge, laminated not undulated 
structure, and above all by the brUliant nacre, and rich brown- 
ish-purple, metallic lustre of the interior. A few flattened 
knobs appear on each side of the hinge in one valve, fitting 
into corrcspoudmg depi'essions in the other. Muscular scar 
large, reuiform, variable. This shell has long been known 
from a large series of very fine African specimens in the Bristol 
Museum, now, alas, for the most part lost. A valve which 
came into my possession in the year 1836 contained abundance 
of Lithophagus aristatus, and 2 valves of Placunanomia per- 
noides : I believe also that valves of Petricola robusta were 
out of the same oysters, as there was at that time scarcely a 
single West Coast shell in that Museum ; but of this I am not 
aertain. On finding the same Oyster and the same Placuna- 
nomia, along with the same Lithophagus, in the Mazatlan 
collection, I sought for further confirmation of so singular a 
fact in geographical distribution. I therefore not only referred 
to the Bristol Mus. Cat., in which the localitj^ was entered as 
"West Africa" in Mr. S. Stutchbury's own hand ; the em- 
ployes at the Institution bearing testimony to the same fact ; 
March 1856. p 



158 MAZATLAX BIVALVES 

but I disentombed the remaining valves, carefully collected 
the dirt from them, and examined their surfaces. I found 2 
perfect specimens of PL pernoides, and many of Lith. aristatus, 
as well as some red coral on the valves ; and among the dirt 2 
(well known African) species of Cardita, 2 of Area, 3 of Odos- 
tomia, a Chemnitzia, FissureUa, Margarita, Purpura and some 
fragments, none of them occurring on the Mazatlan coast, as 
well as KeUia suborbicidaris, which is supposed to be common 
to both seas. The locality is further confii'med by the constant 
trade from Bristol to the Senegambia coast, while there was 
none (at that time) to West America. Of the specimens in 
the British Mus., one is from Anamaboa, an island in the 
W. African seas ; it contains Lith. aristatus, Vermetus glom- 
eratus, and two young specimens of Placunanomia which 
agree with PL pernoides in all respects except that the colour 
is lighter. This is probably from youth and want of light, as 
I discovered them at the bottom of a Lithophagus burrow, 
tightly wedged. The other specimen from an unknown locality, 
(? Australia, Gray) appears to be from the same seas, from its 
having the same Lith. aristatus, the same Vermetus, 2 attached 
valves of the same Plaeimanomia, as well as a young Hipponyx 
(not W. Coast Am.), Saxicava ? arctica, and a^ead Lucina too 
imperfect for identification. 

The Mazatlan shells appear when young to be destitiite of 
denticles. Though normally very distinct from O. Virginica. 
yet they sometiiues approach it in form, developing a very 
long and waved ligament area, which is then somewhat hol- 
lowed out inside, though never so much as in O. Virginica. 
The smallest valve identified measures * 18 : the largest, (which 
being from an unknown locality, though probably from Mazat- 
lan, I have not ventured to include in this collection,) is of 
regular growth, adherent all over to a very flat surface, and 
measures loncj. y25, lat. 6 '3, alt. 2 '07. My African valve 
which is of more normal shape, measures long. 8' 3, lat. 4"2. A 
very bi'oad specimen measures Jony. 4'2, lat. 4'3. A curiously 
distorted one measures long Go, lat. 28; of the length almost 
(when perfect, quite) one liialf consists of hinge area, in lami- 
nated chambers ! 

^«^;.— Panama ; attached to ledges of rock by the greater part 
of the lower valve, near half tide level, not common; C.B. 
jlciawj.v.— West Coast America, ZT/wcZ^. — Guacomayo ; ou 
rocks at low water ; Cww/wflr.— Mazatlan ; very rare ; L'pool 
^ Mavre Coll.—W. coast Africa ; v. supra. 



MAZATLAN BIVALVES 159 

Tablet 702 contains 4 young valves, side denticles not deve- 
loped. — 703, an adult specimen, normal stape. — 704, do. very- 
transverse. — 705, do. with, very elongated Kinge, (from the 
Havre Col.) kindly presented by S. Hanley, Esq. 

212. OSTEEA ViEGINICA, Gmel. 

Gmel. p. 3336, no. 113, teste D/ZZzo. and Wood. — Dillw. Descr, 

Cat. p. 277.— Wood. Ind. Test. p. 52, no. 68.— iam. An. s. 

Vert. vol. vii. p. 225. no. 18. — Conr. in Journ. Nat. Sc. Phil. 

1829, p. 212, 216.— Sow. Gen. f. 2. 
Ostrea Virgiaiaua, Gmel. teste Lam. loc. cit. et Gould Inv. 

Jifass. 
Ostrea rostrata maxima, Chenin. Conch. Cab. vol. viii. p. 38, pi. 

73, f. 677. 
Ostrea elongata, Soland. ms. -.-Portl. Cat. p. 55. 
Sen. = Ostrea erassa, Chemn. loc. cit. p. 40, pi. 74, f. 678. 
Jun. = Grypb^a angidata, Lam. loc. cit. p. 203, no. 1., teste 

Sir W. C. Trevehjan in B. M., non auct. 
+ Ostrea Canadensis, Lam. loc. cit. p. 226, no. 19, teste Desh. 
? + Ostrea longirostris. Lam. loc. cit. p. 243, no. 17, teste 

Trevelyan ; sed v. Desh. in loc. 
? Ostrea sp. ind. d. C. B. Ad. Pan. Shells, p. 246, no. 383. 
Jun. ? = Ostrea rufa (pars), Gould, ms. (California.) 

As tbe few specimens of this sbell sent in the Mazatlan 
collection do not offer any marks by wbicb tbey can be distin- 
guished from the Atlantic O. Yirginica, I have followed Mr. 
Hanley in referring them to that very variable species. So 
like are they, that I have unfortunately distributed many 
specimens in Mazatlan collections, received from a trustworthy 
dealer as from there, which the detection of an entombed 
Mj'tilus, known to be a W. Indian and not a Pacific species, 
has proved to have come from the Atlantic waters, probably 
from Honduras. These differ from the authenticated Mazatlan 
specimens in being generally straighter, shorter, thick, with 
the museidar impression more deeply coloured and lower down : 
but these characters are not constant in either series. C. B. 
Adams remarks of his Ostrea d, which usually occui's in clus- 
ters, that the flavour is superior to that of O. Virginica or O. 
borealis : but the same may be said on comparing varieties of 
O. edubs with each other. The O. Virginica is thus described 
by Gould. " Shell elongated, narrow ; beaks pointed, not much 
curved ; Hgamentary eminence of the upper valve extending 
back to the apex. This is the common oyster of the Chesapeake 



IfiO MAZATLAN BIVALVES 

Bay : occasionally found near Boston, and also at Prince Ed- 
ward's IsL, St. Lawrence " : (? = 0. Canadensis, Lam.*) Conrad 
quotes it as fossil in Maryland and as common to the U. States 
and Europe recent : "Found at ISTissau, between Narbonne 
and Beziers in France, teste Brongniart." A similar sliell is 
in the Br. Mus. from Africa. Another specimen, from the 
mouth of the Tagus, with a fossil from Lisbon, are marked 
O. lougirostris. Lam. Thc.y are considered a var. of O. Yir- 
ginica by Sir W. C. Trevelyan, who also states that the young 
is the Grrypha^a angulata of Lam. The type specimen of the 
latter in the Br. Mus, and the young speciniens from Mazatlan, 
appear to me, though not to more experienced naturalists, to 
(^onfinn this opinion. The species is also from the Portugal 
Coast in the Bristol Mus. ; aud specimens which appear exactly 
like those from ? Honduras are in the Br. IMus. from China, 
on the authority of Tradescant Lay, Esq. The form is also 
from Australia ; Mus. Cumiug. The Mazatlan shells when 
adult are generally rather incurved, thin, with the attached 
valve convex, foliated, and undulated with very indistinct 
radiating furrows, which do not appear at all on the flat upper 
valve. Cartilage area in the lower valve long, deeply undu- 
lated, generally pointing to the left, sometimes to the right, or 
straight. Attachment sometimes only to a stick, sometimes to 
shells by a large part of the surface. When young, sometimes 
shaped like the adult, sometimes very broad and spreading 
lieyond the inner margin, as though in search of a firm founda- 
tion for future prolongation. The umbo is then often sub- 
spiral. In this state it may be generally distinguished from 
neighbouring species by the rich sub-nacreous orange and 
violet colouring, and absence of crenations near the hinge. 
Sometimes however it is nearly white, as it genei'ally is when 
adult. The musciJar scar is generally kidney-shai)ed, but 
varies in almost every s])ecimeu according to the breadth or 
prolongation. The hinge area is generally hollowed beneath. 
The youngest identified specimen is '93 long, of which '16 is 
spiral ligament-aroa ; anotlier, not so long within, has a straight 
area measuring "31. The largest specimen in Mr. Darbishire's 
collection, measures loiiff. 9 '5, lat. 2'1. 

Ifab. — Bay of Guayaquil ; in brackish water on mud banks ; 
Cuming. — Mazatlan ; very rare ; L'pool Sf Havre Coll. — 
[For localities in other seas, and fossil, v. .vwjjra.] 

* Lamarck's O. Virginica is oharaeterizecl b_v a violet stain on the rausculai- 
impression ; but Desh. states that the specimens ticketed in his own hand writ- 
ing have the unpressiou white, while iu his O. Canadensis it is violet. 



MAZATLAN BIVALVES 161 

Tablet 706 contains a young valve, '68 long, and a larger 
pair, broad spreading form, hinge straight.— 707, 1 do. hinge 
spiral. — 708, 3 pairs and a valve, different ages, forms and 
colours.— 709, Area grandis, with valves of O. Virginica at- 
tached. — 710, an adult sp. attached to a twig, with another 
valve, 4'o long, attached to it by its whole length.— Another 
of intermediate size will be found on tablet 20 ; and a valve 
with Crucibulum. 

Tablet 711 contains a very small Gryphaea-shaped shell, 
with spiral umbos, "11 in length, which is probably the young 
of this species. 

213. OSTREA COLUJIBIENSIS, Hani. 

Froc. Zool. Soc. 1845, p. 107 : — non Ostrea sp. ind. c, C. B. Ad. 

Pan. Shells, p. 246, no. 382. 

Shell inside without denticles, of a pure white, resembling a 
small O. edulis ; hinge area very small. Outside smooth, or 
with lamina3 of growth ; light ash, with numerous narrow raj's 
of purple. Eather thin, flat, attached by the whole surface. 
The largest valve (abnormally produced) measures lo7ig. 1 ' 55, 
lat. 1-24. 

Hab. — St. Elena ; adhering to rocks at half-tide ; Cuming. — 

Mazatlan ; on shells and barnacle-covered rocks, very rare ; 

L'pool Col. — Lower California, on Ai'ca grandis, Grould's Col. 

Tablet 712 contains a very young pair, detached, and a valve 

on Imperator unguis. — 713, 2 upper valves. — 714, 2 pairs, very 

flat and iinder valve spreading, probably belonging to this 

species, though approaching some forms of O. Virginica, jun. 

214. OSTKEA CONCHAPHILA, n. S. 

O. t. plerumque parvd, tenui, suhovaU, testis variis affixa ; 
purpurea, smpe aurantid tincta, interdum radiis una vel duahus ; 
cardine parvo, utroque latere denticuUs crenato ; area Ugam%nti 
angustd, triangulari, scepius sulco dcnticulato utraque parte 
extus oniatd ; plerumque totd valvd affixd, margine integro, 
sed interdum suhiter ascend.ente, margine undato, vix plicato ; 
intus suhnacreo, cicatrice modico, irregulari. 
? = Ostrea sp. ind. c, C. B. Ad. Ban. Shells, p. 246, no. 382. 

Shell, when delicately gro\m among Pinna; and Anomiae, 
closely resembling O. bicolor. Haul. (Broc. Zool. Soc. 1845, 
p. W7 -.— Conch. Misc. pi. 1, f . 2 : supposed to be from West 



162 MAZATLAN BIVALVES 

Africa ;) from wliicli it is known by tiie minute denticles on 
each side of tlie liiuge. One valve, of a rich orange within, 
lias a deep purple streak outside gradually shading off into the 
most delicate penciling, and another faint ray of clouded 
purple, leaving two orange areas ; the purple bordering the 
inner margin, and shading most exquisitely into the orange. 
Oysters are rarely seen of such surpassing beauty. Ordinarily 
it is a very small ijurple shell, fi'equenting other shells even 
when Hving, and often interfering with their growth. It is 
known by the very small triangular ligament area, with very 
fine denticles on each side. In addition to these, there are 
generally (in the attached valve) two Unes of denticles situated 
in furrows running outside the area to the umbos. It begins 
life as a swollen regularly formed body, of the shape of Astarte 
compressa. A specimen from S. W. Mexico, in a dead C3'praea, 
retains this regularity and general form : it is smooth, white, 
and convex. The hinge .of the attached valve, when extremely 
young, reminds one of Mesodesma ; the ligament being internal 
between two raised processes followed by pits ; the processes 
afterwards developing into the ligamental area. Sometimes 
the shell becomes rather thick, and, after continuing smooth 
and flat, suddenly rises, and waves (almost ])licating) the outer 
margin. The young of the stronger shells being brilliant in 
colour, might easily be taken for those of O. iridesceus : if 
however, (as I have supposed from the valves already quoted) 
the yoiuig of that shell is not crenated, the denticles afford a 
good distinguishing character ; and, at a later period, the 
crenated sulci round the area. I have specimens received as 
from W. Africa, at any rate inhabiting an Atlantic Pinna, 
which present the same colouring, habit of growth, and some- 
what remarkable liinge. They seem from the crenations not 
to be the j^oung of O. bicolor. The finest grown specimen 
measures lun<j. 1'0-i, ltd. 'd\i, alt. "12. 

Hah. — Mazatlan ; not uncommon, on various shells, v. infra; 
L'pool Col.—S. W. Mexico, do., P. P. C.—? Panama, at- 
tached to stones, rocks and shells, near half-tide level, C. B. 
Adams. — San Diego, very fine ; Lieut. G-recn. — San. Diego 
and Oregon ; Nut tall. — ? W. Africa, in dead Piima rudis, 

P. P. a 

Tablet 715 contains 1 pair and 7 valves, extremely yotmg, 
the smallest "(H across, chiefly from Chamre and Spondyli. — 
716, a sp. of Auomia lampe, with extremely young oysters in 
situ.— 717, 1 valves, a stage older.— 718, a young sp. opened, 



MAZATLAN BIVALVES 163 

on Auomia lampe, shewing the hinge.— 719, 3 valves approach- 
ing O. iridescens.— 720. 3 do. purple, one with the form of 
Modulus to which it had attached itself.— 721, 5 do. orange 
tinted.- 722, 3 do. stronger texture.— 723, very young speci- 
mens on Anomia lampe, with Vermilise, &c. — 724, do. on Cre- 
pidula and Imperator.— 725, a very regular valve on Conus 
regiUaris.— 726, a pair and valve on living Modulus. The 
latter must have been greatly in the way of the creature when 
it walked out : on coming to the extremity of the sheU, it has 
turned up and waved its margin. — 727, a very smooth sp. inside 
Trochus versicolor. — 728, 2 finely grown large valves. — 729, 2 
pairs and valves on Miu^ex nigritus, jun., margin turned up 
and waved. — 730, a paii- (and valves) on Area tuberculosa ; 
margin of both upper and lower valve very suddenly turned 
wg and waved. 

Tablet 731 contains 6 valves, solid white variety, known 
from O. Columbiensis by the crenations.— 732, valve on Vitu- 
laria salebrosa. — 733, crowded valves on Area tuberculosa. 
N. B. Dead valves, common on this shell, assume an ochre 
yellow coloui-.- 734, valve on living Modulus, with deep hinge 
cavity. 

214, b. OSTBEA ?? CONCHAPHILA, var. PALMTJLA. 

O. ?? conchaphila, t. satis maffnd, margine suhito ascendente, 
valvd inferiore su-perante, undidaio, Umbo piirpureo seu olivaceo 
irregulariter tessellato ; I'mea imstularum valvd superiore, in 
parte nacred, a margine remotd, circumeunte, in puncta conveni- 
entia valvd inferiore aptante ; i^ugind interna subnacred, auran- 
iio seu purpurea tinctd ; rarissine spinis ramosis paucis, tubulis 
ad marginem exteriorem arbor escentibus. 
Compare Ostrea Cumingiana, Dlcr. Zeit. f. Mai. 1846, p. 48. 

(Patria ignota.) 

Hemarkable for the palmated foliations in the outer margin, 
which has a distinct limb mottled with purple and olive ; and 
for the row of denticles within this limb and within the nacre- 
ous border, fitting into corresponding depressions in the other 
valve. As these seem to appear only in the adult shell, it is 
barely possible that O. conchaphila may occasionally develop 
itself into this form. Mr. NuttaU however agrees with me in 
regarding them as distmct. Long. 2 '3, lat. 1'6, alt. '54. 
JBTaJ.— Mazatlan ; extremely rare ; L'pool Col. — S. W. Mexico, 

P. P. C. — Upper California, NuttaU, 



164 MAZATLAN BIVALTE9 

Tablet 735 contains a young elongated specimen. — 736, 
another, rounded form, with a few tubular spines near the mar- 
gin of the upper valve. — 737, the largest sp. with Vermetidae, &c. 

215. OsTBEA , sp. ind. 

P = Ostrea sp. ind. e, C. B. Ad. Pan. Shells, p. 246, no. 384. 
Ostrea iridescens, jun. P. P. C. Cat. Prov. 

Agreeing with O. iridescens in its square form, straight 
hinge, and nacreous interior ; differing in the irregular radia- 
tion of the lower valve, and strong sharp plication of the mar- 
gin. This differs from the undulated margin of O. c. palmula, 
in not having a distinct limb, with remote line of denticles. 
These, if present, are very small, and rather near the margin. 
The characters are so variable that I should have continued to 
regard this as the j'oung of O. iridescens, but for finding 
specimens of the latter without hinge denticles, which in these 
shells are strongly marked ; and for the remark of Prof. Adams, 
with regard to what appears the same species, that the animal 
has a bitter flavour. Long. 2 '5, lat. 2 '5, alt. 1'35. 
Hah. — Mazatlan ; very rare, on shells ; L'2)ool Col. — ? Pan- 
ama ; very common, attached to rocks and stones from one 
to three-quarters tide level : small var. on Nerita scabri- 
costa; C.B.Adams. — '^SlVl Diogo, Lieut. Green. 
Tablet 738 contains 7 verj' young vah'es, oiF Spondj'li and 
Chamse. — 739, 1 do. on Imperator olivaceus. — 740, 1 do. on 
Imp. unguis, distorting the shell. — 741, 1 yoimg, white valve, 
resembling O. Virgiuica, but Avith crenated liinge. — 742, 2 
valves approaching O. iridescens. — 743, 4 paii-s strongly plicate, 
green within. — 711, 1 large pair, attached by portion of the 
valve to Piima. 

Family .iJS^OMLlDyE. 

Genus PLACUNANOMIA, Brod. 

Brod. in Proc. Zool. Soc. 1832, p. 29.— Gra// in B. M. Cat. 

Anom. p. 8. 
Subgenus INIouia, Gray, Proc. Zool. Soc. 1849, p. 121. 

216. Placcnanomia peknoides, n. s. 

P. t. forma ma.vime variante, interdum transversA, inferdum 
maxime elongata, valva inferiori maxime perforata, cuneo intus 
liris haud tcnuihus instructo, fulcro ligamenti valde extante, 



MAZATLAN BIVALVES 165 

spatkuloso : valva superiori muse, cicatr. duahus, quarum una 
magna, centralis, radiatim temdssime striata ; alter haiidparva, 
alteri attingens ; lined pallii perdistincta unam alteramque 
amplectente ; colore atropurpureo, seio atrofusco, suhnacreo, 
splendente ; extus interdum radiatim tenuissime striata; um- 
hone a margine suhdistante. 

Comp. Tedinia pernoides, Gray, Proc. Zool. Soc. 1851, p. 197-8. 
Jim.=Anomia, sp. 3. P. P. C. Cat. Prov. 

Tliis shell lias long beeu known to me from two attached 
valves on an African specimen of Ostrea iridescens ; v. supra : 
but not being aware that it was undescribed, Dr. W. B. Car- 
penter destroyed one of them for examination into the shell 
structure. On finding the same species on Chama at Maz- 
atlan, and comparing it with the types in the B. M. and 
Mr. Cuming's Collection, it appeared new, diifering from all 
described species in colour, which is peculiarly dark and 
lustroiis. On the Mazatlan ChamaB and Spondyli were found 
the specimens below enumerated, also a small ovate valve, and 
a beautiful pair in the collection of Mr. Darbishire. On the 
African oysters in the British and Bristol Museums I also 
foimd specimens as above stated. Mr. Archer has in his col- 
lection a magnificent upper valve, measuring 2' by 2' 4 in., 
wluch he found among the rubbish from a ship laden with 
pearl oysters from Panama : all the other shells from the same 
rubbish were known to be from that coast. The Tedinia 
pernoides of Gray, described from an extremely distorted 
specimen in Mr. Cuming's Collection, is so very like this shell 
in its leading characters that I am strongly of opinion that 
they are identical. jMr. Woodward, who had not felt sufficient 
confidence in Dr. Gray's genus to admit it into his Manual, 
examined the shell with me, and we were both doubtful 
whether the supposed additional musciilar scar near the hinge 
was more than a peculiarity of growth. There were so many 
lines traceable on the inner surface that a naturalist so disposed 
might have arranged almost as many muscles as he thought 
desirable. The point must await the amval of fresh specimens. 
To pro\Hde for the case of my suspicions being correct, I have 
given the same specific name to this which is a veritable 
Placunanomia. The structure of the inner surface of the plug, 
Avhich is large and coarse, does not appear horny under the 
microscope ; but composed of parallel shelly plates with much 
animal matter interlying. The largest Mazatlan specimen 



166 MAZATLAN BIVALVES 

measures lo^iff. l'34i, Iat.1'82, ait.'SQ: an elongated valve 
from the hole of a Lithodomus, long. 1"52, lat. '6. 
Hah. — West Coast of Africa ou Ostrea iridescens, Stutchhivry. — 
Mazatlan ; extremely rare, on Chamse and Spondyli ; L'pool 
Col. — Panama, among pearl oysters ; F. Archer. 
Tablet 745 contains a young perfect pair, both valves detach- 
ed, with hole like Anomia. — 746, a broken attached valve, 
shewing the hinge and i^ortions of the plug. — 747, the elongated 
valve. — 748, the large^ x^air, detached, nearly perfect. 

217. Placunanomia foliata, Brod. 

Brod. in Proc. Zool. Soc. 1834, p. 2. — Gray in Proc. Zool. Soc. 
1819, p. 121 :—B. M. Cat. Aiiom. p. 10.—^. M. Cat. B'Orb. 
Moll. p. 88, no. 778. 

+ P. echinata, Brod. loc. cit., teste Gray. 

+ "P. pectinata, Brod." in Mus. Cuming, teste Gray. 

Subgenus Pododesmus, Phil., Gray in B. M. Cat. Anom. 
loc. cit. 
Only two young and transparent valves were found of this 

species. White. Avith central brown stain ; outside with 

l^rickly longitudinal stria?. They seem to agree with a very 

characteristic valve found in the S. W. Mexican collection. 

Long, "75, lat. "57. 

Sab. — Guayaciuil Bay ; on dead Pinna in sandy mud, 11 fm. ; 
Cuming. — Ecuador, Guayaquil, D'Orhigny. — Isle of Muerte, 
Broderip. — Martinique, no. 6, and Brazils, no. 7 ; Mus. Cum- 
ing. — St. Vincent and Jamaica, Rev. L. Gnilding in B. M. — 
S. W. Mexico P. P. C. — Mazatlan ; 2 valves in Spondylus 
calcifer ; L'pool Col. 
Tablet 71'9 contains the larger valve and fragments. 

218. Placunanomia claviculata, n, s. 

P. t. suhorhiculari, tenuissimd, planatd,\l(evi, sen striis in- 
crementi exiUiniis : albd, macula brunned, discam candidam 
j)ynformem hand distinctam circumeunte ; valvd inferiori hya- 
lind, perforaiione magna, fulchro yj-formi : lamelld albd acutd 
jjrope pierforutionem intus decurrente : valvd siiperiore muse, 
cicair. majore .suhovali, minore rotundatd, viodice ncparatd. 
Subgenus Monia, Gray, loc. cit. 
Anomia, sp. 2, P. P. C, Cat. Prov. 



MAZATLAN BIVALTES 167 

It is SO easy in tliin Anomiadse to see tlie muscular scars one 
expects, that I had sketched 3 scars for this species to shew 
the difference in arrangement from those of A. lampe, of which 
many conchologists had considered my valve a varielj-. Having 
however found a pair, and being struck by the V-sliaped notch 
at the cardinal end of the hole, I re-examined the scars, and 
found the supposed third to be only one of those non-muscidar 
impressions which are very liable to deceive beginners till they 
have learnt from books what they ought to look for. Shell 
extremely like Anomia lampe (smooth var.) ; from which it is 
known at once by the brown disk, inside which is a very faint 
white disk, with the extremity rounded, not triangular. It is 
known from P. foliata by the entire absence of radiating 
strige, which are very conspicuous in yoimg shells of that 
species. A remarkable feature in this shell is the sharp white 
lamina, (or clavicle,) which runs from the hinge in the lower 
valve, near the hole but not parallel with it, losing itself in a 
thin white deposit in which is the muscular scar. This clavicle, 
or lengthened support to the cartilage plate, is also seen in P. 
Cumiugii, large, rounded, and I'unning in a straight line to the 
muscular scar. It is more or less developed in some other 
species of the genus ; but is remai-kable in this for its length, 
direction and sharpness. Long. 1"12, lat. 1"4.6, alt. "16. 
Sab. — Mazatlau ; one pair and a valve with Anomiae; L'pool 
Col. 

Tablet 750 contains the pair. 

Genus ANOMIA, Linn. 

219. Anomia lampe, Gray. 

Ft'oc. Zool. Soc. 1849, p. 117 ;— -B. 3L Cat. Anom. p. 19, sp. 

14,.— C. B. Ad. Pan. Shells, p. atl, no. 377. 

This shell in its ordinary state would hardly be known by 
the meagre description in the B. M. Cat. ; but tlie very numer- 
ous finely grown specimens sent in this collection give oppor- 
timity to record its leading features. Many hundreds were 
sent carefully packed ; but most have been broken since they 
came to this country. There was also a box of valves, many 
of them extremely brilliant, from which I picked the valve of 
P. claviculata ; doubtless there were many other treasures in 
it, but it was unfortunately sold off to make ladies' fanc}- work 
before I had an opportunity of examining it. 



168 MAZATLAN BIVALVES 

Shell extremely thbi ; lower valve white, smooth ; iij^per 
whitish, more or less stained with golden yellow, rarely salmon 
coloured, extremely rarely greenish, most rarely with a slight 
touch of pink ; smooth, generally developing irregular radia- 
ting ribs near the margin, sometimes strong ones all over. 
Occasionally concentric waves of growth are developed. Lower 
valve dead white within near the somewhat large (sometimes 
small) hole, gradually becoming transparent ; upper valve 
with a defined white spathula, somewhat in the shape of an 
isosceles .triangle with an excurved base, radiating from the 
light green ligament, and enclosmg the scars. The plug scar 
is not much larger than the others, and is rounded subquadrate. 
The others are round, slightly separated, and at a variable 
angle according to the shape and age of the shell. In different 
specimens examined, the lines joining the centres of the ter- 
minal scars with the centre of the middle one, are inclined at 
angles varying from 105° — 133" ; shewing hoAV necessary it is 
to be cautiou-S in founding species merely on the i^osition of 
the scars. If this divergence of central angle were given in 
descriptions, it would greatly aid the student. The subcardi- 
nal scar is small and very slightly impressed. There is a short 
support from the hinge fidcrum in the lower valve. The plugs, 
of which a few were fortunately preserved on the outer valves, 
are very different in appearance from those of A. ephippium ; 
being large and spreading at the base, but short and small in 
the attached portion. Extremely fine lines run down the raised 
l^art to the margin of the base , but the rest of the base is not 
grooved. As the shell grows older, it appears to increase the 
raised part near the umbo, withdrawing from the grooved part 
of the base, which is no longer covered by the hole. The hole 
is very much larger than the raised part, which fills only the 
middle of it. One plug has a large tail, like the expanded foot 
of a Cyclas, from the gradual shifting of the animal. The raised 
part has generally a horse-shoe extremity, sometimes built up 
with very loose shelly matter. The plug under the microscope 
appears essentially sheUy, though with much animal matter. 
Very young sliells are generally orbicular, beginning life as an 
irregular body without prominent apex, shaped like Discina. 
The smallest valve is ' 09 across ; the largest specimen measures 
hmg. 1'9, lat. 2-41, alt. -14 

Hah. — California Ladi/ Ulf/ram, B. M. — Monterey, 60 fm., Ma- 
jor Rich. — La Paz, do. — Panama ; at low water mark ; 1 sp. : 
C. B. Adams. — Mazatlan : common and very fine ; L'pool Col. 



MAZATLAN BIVALVES 169 

Tablet 751 contains 4 valves, extremely young. — 752, 6 sp. 
usual state. — 753, 2 do. concentric furrows developed. — 754, 
6 do. radiating ribs strongly developed. — 755, 4 sp. finely 
grown, ribs slightly developed. — 756, 3 do. concentric linos 
marked. — 757, 3 do. almost smooth.— 758, 2 do. waxen aspect, 
like Placunanomia claviculata. 

Tablet 759 contains 3 sp. bright yellow. — 760, 2 do. greenish, 
? from Conferva?. — 761, 2 do. with tinge of pink. 

Tablet 762 contains 3 sp. salmon tint, radiated. — 763, 1 do. 
with concentric waves. — 76ii, 1 do. with greenish. — 765, 1 do. 
grown over with Vermilia;, which indent it throughout. — 766, 
1 do. square form, with Vermilias attached : (a beautiful little 
species, often found on this and other delicate shells.) — 767, 4 
lustrous valves, shewing changes in the central angle of scars. 

Tablet 768 contains 2 sp. distorted growth, inflated. — 769, 3 
do. corrugated surface. — 770, 3 do. transverse growth. — 771, 2 
do. indented. — 772, 3 do. right side cut off at various angles. — 
773, 4 do. left side do. — 774, 3 do. vertex, distant from margin. — 
775, 2 do. hole small. — 776, 1 do. with remarkable rows of egg 
cases. 

Tablet 777 contains 3 sp. with variously formed plugs attach- 
ed. — 778, a sp. with young attached : both valves are removed, 
shewing its own plug, and another small one near without 
corresponding shell. — 779, another sp. with young attached ; 
the upper valve only is removed, shewing the lower in situ. — 
780, 9 pairs and valves shewing interior. 



220. ? , sp. ind. 

Tablet 781 contains a minute valve, (foimd since the first part 
of this Catalogue was printed,) of which it is hard to tell even 
the generic place. The outside has the general appearance of 
Sphaenia fragilis ; extremely thin, transparent, covered with a 
copious epidermis with rather distant concentric layers ; very 
insequdateral, with an obscure angle from the very projecting 
umbos to the posterior end. Hinge with two long lamellar 
teeth, one going posteriorly from the umbo, the other parallel 
to it, nearer the anterior end. Ligament apparently external, 
very thin. Long. "05, lat. "027, alt. '007. 

Hab. — Mazatlan ; one fresh valve off Ostrea iridescens ; 
L'pool Col, 

March 1856. „ 



170 KAZATLAN UNIVALVES 



CLASS PTEROPODA. 

Omnia adhuc iguota. 



CLASS GASTEROPODA. 

The knowledge of this class of MoUusks has rapidly increas- 
ed since attention bas been paid to their mouths and teeth. 
The main divisions here adopted are probably well founded. 
In the smaller sections we do not as yet know enough to 
stereotype an arrangement. Whatever character be taken as 
the 'guide, families are united, unlike in other respects, or 
separated when many points of structure indicate aflinity. The 
science being in a transition state from the old conchological 
arrangements, all dogmatism, on any side, is clearly out of ptace. 

Sub-class OPISTHOBRANCHIATA. 

Obder TECTIBEANCHIATA. 

Family CYLICHNID^. 
Genus CYLICHNA, Loven. 

221. Cylichna luticola, C. B. Ad. 

Bulla (Cylichna) luticola, C. B. Ad. Pan. Shells, p. 215, no. 

320 : do. p. 319. 
Haminea luticola, H. Sf A. Ad. Gen. vol. ii. p. 16. 

Shell remarkably constricted in the middle, swelling an- 
teriorly. Tlie surface is extremely finely decussated between 
the weU-marked stria; of grewth. Long. '1, lat. "04. 
Sah. — Panama ; crawling on liquid mud, near low water mark, 

at the bottom of a steep sand beach, rare ; C. B. Adams. — 

Mazatlan ; 2 dead specimens off Chama ; L'pool Col. 

Tablet 782 contains a characteristic specimen. 



MAZATLAN UNIVALVES 171 

Gentjs TOENATINA, A. Adams. 

Distinguislied from Cylichna, Loven, by the head being de- 
veloped behind into tentacular lobes. Shell with the spire 
distinct. Columella with a spiral plait. 

222. TOENATINA INFEEQUENS, C. B. Ad. 

Bulla (Tornatina) infrequens, C. B. Ad. Pan. Shells, p. 214, 

no. 319 ; do. p. 319. 
P = Bulla (Tornatina) gracilis, like, (non A. Ad.) Zeit.f. Mai. 

1850, p. 162, no. 3. 

Menke's species being white, not horn-coloured like T. gra- 
cilis from the China Seas, and being identified from a single 
specimen wedged in the mouth of a dead Conns puncticulatus, 
is almost certainly the same as that described by C. B. Ad. 
from Panama. T. infrequens is distinguished by the Oliva- 
like sj)ire, more or less elevated and deeply channeled along 
the suture. The body whirl is not swollen anteriorly, and the 
fold lies slanting on its base. Long. '14, long, spir.' 03. lat. '05, 
Sab. — Panama; extremely rare; C. B.Adams. — Mazatlan; 

very rare,. on Spondj'lus calcifer ; L'j^ool Col. 

Tablet 783 contains the finest specimen ; and the smallest 
measuring, '07 in length. 

223. ToENATINA CAEINATA, 71. S. 

T. t. cylindraced, alba, Icevi, infra suturam appressam acute 
carinatd ; inter suturam et carinam excavata ; anfr. v. quarum 
duo primi discoidales, ad spiram verticaliter affixi ; spird plus 
minusve extante ; aperturd prcelongd, labro acuto, in medio 
producto, postice ad suturam vix canaliculato ; labro tenui ; 
pariete ad basin tumidd ; columella plied infra parietem robusta 
spiraliter munitd. 

Known from T. infrequens (1) by the smaller size, and more 
irregular spire ; (2) by the suture, which is not channeled ; 
(3) by the shoulder, which is sharply carinated, with the space 
hollowed between the keel and suture ; (4) by the swelling of 
the body whirl at the base ; and (5) by the plait which runs 
more transverselj'', below the body whirl, instead of obliquely, 
almost on it, as iu T. infrequens. By some of the above char- 
acters it is further distinguished from T. cerealis, Gld. (Mex. ^ 



172 MAZATLAN TTNIVALVES 

Cal. SJiells, p. 5, Sta Barbara, Jcwett,) wMcli resembles T. 
infreqiiens mucli more closely tliaii tbis species. All the three 
forms begin life as a small discoidal body, like a tumid Planor- 
bis. After making about two turns of this, they proceed in the 
regular way, affixing the disk vertically, or sometimes in a 
slanting direction, at the top of the spire. The length of spire in 
this species, which is not so rare as T. infrequens, is extremely 
variable. The smallest specimen is '037 long. The largest 
measures long. 11, long. spir. "02, lat. '05. The discoidal apex 
is "005 across. 

Sab. — Mazatlan ; on Chama and Spondylus, very rare ; 
Upool Col. 

Tablet 784 contains 5 sp. varying in age and shape, and a 
fragment to shew the apex. 

Family BULLID^. 
Genus BULLA, Klein, 

224. Bulla Adamsi, ISIke. 

Zeit.f. 3f(d. 1850, p. 162, no. 1. (syn. excl.) 

Dr. Menke regards this shell as that figured in So7v. T/tes. 
Conch, f. 64, 65, under the name of B. australis. Li this he is 
probably mistaken, but not in regarding the species as distract 
both from that and from B. Panamensis. Phil. It greatly 
resembles B. media, Phil, and still more B. major, Phil., both 
from the West Indies. It differs from the Upper Californian 
B. nebulosa, when adult, in being much smaller, more sofid 
and contracted, and in having a much larger umbilicus. Shell 
chocolate coloured, very variously dotted with white, shadowed 
off" in dark. Lip at the ])aso strongly reflected, in the young 
shell distinct from the lalnum, whicli is well marked, white. 
Apex deeply umbiiicatc, shoM iug the whirls and with the inside 
spirally striated. The whole surface (described by Menke as 
smooth) is covered with extremely fine spiral microscopic striae, 
irregular, sometimes broken into dots by the stria; of growth. 
Epidermis horny, thin. Long. 1'38, lat. '91. 
Hab. — Mazatlan, Menke. — Do. : not common ; L'pool Col. 

Tablet 785 contains 3 specimens approaching B. nebidosa 
in texture.— 786, 2 do. normal form.— 787, 2 do. more tumid, 
strong. 



MAZATLAN TJNIVAITES 



173 



225. BtTLLA Pnebulosa, Gould. 

U. S. Expl. Exp. Moll.—Mke. in Zeii f. Mai. 1850, p. 162, 
no. 2. 

A very few thin, subglobose sliells were found, with a small 
Timbilicus, wliich are undistiaguisliable from the young of B. 
nebulosa ; a species wliich, along with other points of simil- 
arity, shews the spirally striate Timbilicus, and traces (though 
faint) of the rugosely striulate siu-face, of B. Adamsi. B. 
nebulosa is quoted from Guaymas, and may be one of the very 
few Californian species which cross the Gulf. I strongly sus- 
pect however that these are but aberrant forms of the young 
B. Adamsi; which varies not a little in outlme, sohdity, and 
size of umbiHcus. The adult shells are sufficiently distinct. 
Long. 1', lat. '7, 
Sab.— Sta. Barbara, Nuttall — San Diego, Lietit. Green.— 

Guaymas ; in sand, 12 m.; Mus. Cuming.— Mazatlan ; Menke. 

— PDo. jun. extremely rare ; Upool Col. 

Tablet 788 contains the most characteristic specimen. 

226. Bulla ? Quoth, Graij. 

Sow. Thes. Conch, sp. 48, pi. 173, f. 71. 

A very few small specimens were found, differing from B. 
Adamsi'in the following points. Surface much more strongly 
and closely striulate ; outlhie flattened towards the umbilicus, 
at an angle of about 00°. Umbilicus strongly striate, bounded 
by a blunt angle. Lonr/. '5, lat. "B. 
jffai.— Gallapagos, Cuming. — ? Mazatlan ; extremely rare; 

L'pool Col. 

Tablet 789 contains 3 minute sp., probably belonging to this 
species. — 790, the ? adult specimen. 

227. Bulla exarata, n. s. 

B. t. parvd, elliptic^, compressd, apeif'tura elongata, angusta ; 
fused, epidermide teniii cinctd ; spiraliter tenuissime exarata, 
lineis plus minusve distantihus, in medio plerumque evanidis ; 
spird haud alte umhilicatd, intus striulis transversis divaricatd ; 
lahro postice producto ; luhio eolumellam versus rimulam umbi- 
licalem sinnolanie. 

Distinguished by the acuminated form, fine, rather distant 
spiral gi'ooves, narrow produced aperture, and slight iimbilical 
chink formed by a fold of the labium. The small spiral umbUi- 



174 MAZATLAN UNIVALVES 

ous appears slightly denticulate within, from the stria? of 
growth being there well marked. The labrum extends 005 
beyond the spire. Long. ' 125, lat. "055. 
Sab. — Mazatlan ; 2 sp. on Spondylus calcifer ; L'pool Col. 
Tablet 791 contains the larger specimen, slightly imperfect. 

228. Bulla , sp. ind. 

Tablet 792 contains a small fragment, remarkable for the 
sharp angle round the spiral umbilicus. This is furnished 
within with spiral grooves so strongly marked as to cause the 
produced labrum to be serrated on the outer side at its junc- 
tion with the body whirl. 

Sab. — Mazatlan ; on Spondylus calcifer ; L'pool Col. 

Genus HAMINEA, Leach. 
Bulla (pars) auct. Shell horny, elastic, colourless, semi-interna. 

229. Haminea cymbifoemis, n. s. 

S. t. tenuissima, albidd, axi contortA, maxime inflatd, spird 
minore, celatd ; aperturd antice ventricosd, postice productd ; 
striulis spiralibus creberrimis omatd, rugis incrementi subex- 
tantibus ; labio tenuissimo. 

Only one rather imperfect specimen was found of this 
beautiful species, which resembles in form a small inflated 
Cymbium. Long. "07, lat. "05. 

Hab. — Mazatlan ; 1 sp. on Spondylus calcifer ; L'pool Col. 
Tablet 793 contains the specimen. 

SuB-cLAss PULMONATA. 
Obdee GEOPHILA. 
Family TESTACELLID^. 
Gray in B. M. Cat. Pulm. p. 9. 

Genus GLANDINA, Schum. 

Essai Syst. p. 202, 1817. 

Oleacina, Bolten, Mus. (1798) ; ed. 2, 1819, p. 77. 
Cochlicopa a. Ferns. Tab. Syst. 1821. 
Achatina, pars, auct. 



MAZATLAN UNIVALVES 175 

Dr. Gray unites Oleacina, Glaudina and Halia under the 
former name, {B. M. Cat. Pulm. p. 13 ;) H & A. Adams con- 
sider tkem distinct : Gen. vol. ii. p. 107. Ordinary students 
have no power of ascertaining whether generic names given 
with an early date are accompanied by a diagnosis, and there- 
fore of authority, or whether they are only names which have 
been attached to certain species, and not entitled to take pre- 
cedence of a regularly defined genus. — The animal of Glandina 
is said to be carnivorous, and to resemble Testacellas with the 
spiral part developed. 

230. Glandina Albeesi, Pfr. 

Achatina Albersi (Glandina) Pfetf. in Proc. Zool. Soc. 1854, 

p. 295. 

A very few specimens of this impretending species were 
found among the Physse. It appears to take the place of G. 
rosea, foimd lower down the peninsula. The shape is extremely 
variable, being sometimes elongated like G. turris ; sometimes 
very much swollen, with a short spire. A turreted specimen 
measures . . . long. 1-2, lo7ig. spir. -59, lat.'5. 

A swollen sp. . . „ 1", „ "42, „ .5. 

Sab. — Mazatlan ; extremely rare ; L'pool Col. 

Tablet 794 contains 3 sp. : one turreted, one swollen, one 
curiously mended after fracture. 

231. Glandina tueeis, Pfr. 

Achatina turris (Glandina) Pfr. Si/mb. iii. p. 91, no. 126 : — 

Mon. Selic. ii. 2%S.—Rve. Conch. Ic. pi. 13, f. 45.— DesA. I. c. 

186, no. 51, pi. 134, f 1, 2.—B. 31. Cat. Pulm. pt. i. p. 25, no. 29. 
= G. Albersi, var. turrita, P. P. C, Cat. Prov. 
Acicula turris, S. Sf A. Ad. Gen. vol. ii. p. 109. 

This species is kept separate provisionally on the authority 
of Dr. Pfeiffer. As only one specimen was found in the Maz- 
atlan collection, it would not be fair to decide without further 
evidence. It appears to differ from the elongated var. of G. 
Albersi, simply in the still greater elongation, greater arcuation 
of the columella, and greater fineness of the stria;. But all 
these characters are variable in the other species. Long. 1"2; 
long. spir. '61, lat. '48. 
Sah. — Mexico, Liebmann. — Mazatlan ; 1 sp. among Physse ; 

L'pool Col. 

Tablet 795 contains the specimen. 



176 MAZATLAN r^'IVAIVES 

Family HELICID^. 

Genus OETHALICUS, Beck. 

S. Sf A. Ad. Gen. vol. ii. p. 154 Tlie animal differs from that 
of Bulimiis proper, according to Troscliel in Zeit. f. Mat- 
1»47, p. 50, (note.) 

Bulimus, pars, auct. 

232. Oethalicus zebea, Miill. 

Buccinum zebra. Mull. Verm. p. 138, no. 331. — Lisi. Conch. 

pi. 580, f. U.—Fav. Conch, pi. 65, f. M- 2.—Seha, Mus. 3, 

t. 39, f. 54, bo.—Gualt. Ltd. pi. 5, f. N. (Zebra Mtilleri,) 

Chemn. Conch, vol. ix. pt. 2, p. 24, pi. 118, f. \Olo-Q>.—Kam- 

merer, Cah. riid. pi. 80, f. 4. 
Bulla zebra, Gmel. p. 3431, no. 31. — Schroet. Fliissconch. p. 325, 

pi. min. A, f. 4, + no. 123: — Einl. vol. ii. p. 216, no. 143. — 

Dillw. Descr. Cat. vol. i. p. 494, no. 52. 
Bulimus zebra. Desk, in Lam. An. s. Vert. vol. viii. p. 223.^- 

A)iton Verz. p. 43, no. 1577.— B' Orb. Moll. Cub. vol. i. p. 174, 

pi. 6, f. 9. 10.— P/y. Si/mh. no. 372.— Ml-e. in Zeit. f. Mai. 

1850, p. 163, no. 4. 
Achatma zebra, Pfr. Si/mh. ii. p. 135 : non Chemn. nee Lam. — 

Kammcrer, p. 126, pi. 10, f. 4. 
Orthalicus undatus et zebra, Beck. Lnd. p. 59, no. 5, 6. 
Ortbalicus zebra, H. Sf A. Ad. Gen. vol. ii. p. 154, pi. 75, 

f. 6, 6 a. 
Helix undata, Daudeh. Sist. des Moll. pi. 114, f. 5, 8 ; pi. 115. — 

Wagn. in Spix. Test. Braz. p. 9, no. 12, pi. 9, f. 2.—Morie. 

Mem. de Geneve, vol. vii. pt. 2, p. 423, no. 14. — (PZS^onH. 

undata, Dillw. p. 958.) 
Helix (Cocblostyla) nndata, Fer. Sist. p. 337, pi. 114, f. 5—8. 

pi. 115, f. 1— 6.— D'Ori. S>/nops. p. 8. 
Bulunus undatus, Brucj. Diet. no. 38 i-Fnc. Meth. p. 320, 

no. 38. — Lam. loc. eit. no. 5. — Valenc. in Humh. Zool. vol. ii. 

p. 245, pi. 55, f. l.—Kust. Bui. p. 6, pi. 2, f. 4, b.—B. M. Cat. 

B'Orb. Moll. p. 13, no. 134 -.—Cuba Moll. p. 10, no. 93. 
Var. = Bulimus melanochedus, Val. in Sumb. 2^ol. vol. ii. 

p. 21(5. pi. 55, f. 3. 
Var. = OrtbaUeus livens, Beck. lnd. p. 59, no. 7. 
+ Bulimus ziczag. Lam. loc. cit. no. 4, teste Desk. 
+ Bulimus priuceps, Brad. Proc. Zool. Soc. 1832 : — Sow. Conch. 

111. f. 18, 



MAZATLAN TJNITALTE9 177 

Helix (Cochlostyla) princeps, jyOrh. Synops. p. 8. 
Orthalicus princeps, Beck. Ltd. p. 59, no. 3. 
Achatina pulcliella, Spix. 

Tliis well known and widely distributed species is the only 
land shell which appears at all common at Mazatlan. It varies 
greatly in pattern, as wUl be seen by the following list. Most 
of the shells were young, but characteristic. The first 3 or 4 
whirls rarely display any painting. Long. 2'1, led. I'l. 
Hah. — BrazUs, Peru, Columbia, D'Orbigny. — Cuba, Sagra. — 

Conchagua, Broderip. — Mazatlan ; common ; U-pool Col. 

Tablet 796 contains 5 sp., with very large dark patches. — 
797, 4 do. patches diagonal. — 798, 3 do. patches smaller. — 799, 
1 do. patches clouded. — 800, 5 do. gathering into knots. — 801, 
7 do. normal painting, knotted in spiral bands. — 802, 4 do. very 
fine, scarcely zigzag stripes. — 803, 3 do. irregidarly crowded. — 
804, 4 do. knotted pattern extremely faint. — 805, 3 do. yellow- 
ish, with spiral brown lines at the base.— 806, 1 sp. yellowish, 
without pattern.— 807, 5 sp. elongated form. — 808, 1 sp. with 
winter epiphragm. — 809, 3 sp. broken and mended by the 
animal. 

233. Oethalicus Zieglebi, Pfr. 

Bulimus Ziegleri, Pfr. Proc. Zool. Soc. 1846, p. 113, no. 25 :— 

Symb. no. 472. 
Leiostracus Ziegleri, S. 8f A. Ad. Gen. vol. ii. p. 151. 

This shell is placed by Messrs. Adams in a subgenus of 
Otostomus. It has however a sharp, non-reflected lip ; as well 
as a very^ small, scarcely covered umbilicus. A very few speci- 
mens were found with the Physa?. An unusually large one, in 
which the linear patches of colour are almost evanescent, 
measures long. '69, long. spir. '35, lat. '34. 
Hah. — Central America, Largilliert. — Mexico, Liebmann. — 

Mazatlan ; extremely rare ; Upool Col. 

Tablet 810 contains 2 sp., one of normal colouring, the other 
the pale variety-. 

234. Oethalicus PMexicanus, Lam. 

Bulimus Mexicanus, T^am. An. s. Vert. vol. viii. p. 232, no. 23.^> 

Val. in Humh. Hec. Zool. 
Leiostracus Mexicanus, S. Sf A. Ad. Gen. ii. 150. 
?=Helix vittata, Baud. Hint. Moll. no. 397. 



178 MAZATLAN UNIVALVES 

Tablet 811 contains a sketch of a solitary specimen which 
was found by Mr. Archer among the small shells. It was 
referred by Mr. Cuming to Bulinus Broderipii. Sow. in Proc. 
Zool. Soc. 1832 -.—Conch. HI. f. 1. ( = Plectostjlus Broderipii, 
S. ^' A. Ad. Gen. ii. 155 :) but as it does not accord with the 
figures of that Chilian species, it was perhaps an oversight. 
Lamarck's description might also serve for B. Ziegleri, which 
this shell very greatly resembles. It is however more inflated 
and thinner. Long. '65, long. spir. '35, lat. '4. 
JIab. — Mexico, Humholdt Sf Bonpland- — ? Mazatlan ; 1 sp. 

with B. Ziegleri ; L'pool Col. 



Oedee LIMXOPHILA. 

Family AUEICULIDyE. 

Genus MELAMPUS, Montf. 

Melampus, Montf. Conch. Si/st. 1810. 

Conovulus, Lam. 1812. This genus was afterwards suppressed 
by its author, and united to Auricula. 

235. Melampus olitaceus, n. s. 

JkT. t. parvd, suhlcevi, conoided, spird depressd, infra suturam 
indistinctam obscure angulatd ; albidd, fusco-purpureo irregu- 
lariter tessellatd, epiderinide adhcerenfe olivaced indutd ; anfr. 
vii. vix monstrantibus, planatis ; aperturd longd, angustd, ad 
narginem fusco-piirpured, intus alba ; labro ad marginem acuta, 
intus dentato, dentibus in liras acutas, in aduUd sctpe obsoleta.i, 
deeurrentibus ; labio tenui, plied und panetali transrersd, inter 
denticiilas diias sitd, in jiinlore denticulis numerosis intus 
canditis ; columella plica und obliqud, ad basin excurrente ; 
parietibus internis in adultd absorptis. 
Melampus bidentatus, Moerch in Mus. Cum. : non Say. 

Moerch mu.st surely have been in error in regarding this 
species as a variety of ^I. bidentatus. It is much more nearly 
allied to the Voluta coffea of Linn. The specimens, of which 
many hundreds were sent, are very constant in the characters 
above given ; of which the most distinguishing are the oUve 
green epidermis, with the irregular purplish brown tessellated 



MAZATLAN UNIVALVES 179 

patches often shewing througli ; tlie sharp purplish outer lip, 
well armed with white ridges within, in the young shell, which 
afterwards develope strong teeth at the ends, and are last of 
all absorbed ; and the thin inner lip, which developes one 
strong transverse pai-ietal plate between two small denticles 
(others being just discernable in the young sheU), and one 
large slanting columellar fold, which winds round the base of 
the pillar, making an umbilical chink. A few extremely faint 
spiral stria; are sometimes seen on the epidermis, near the 
base and above the bluntly angled shoulder* Long. '65, 
long. spir. '11, lat. '38, mean div. 110". 

Hab. — Mazatlan, Lieut. SJiipley. — Do.; not uncommoa; 
L'pool Col. 

Tablet 812 contains 9 sp. normal state. — 813, 4 do. dark 
variety. — 814, 4 do. Ught var. 

Family LIMNEIDiE. 
Genus APLEXA, Flem. 

Eist. Br. An. 1828, p. tl^.—Gray, Proc. Zool. Sac. 1847, 
p. 180 -.—do. Turt. cd. n.—Bech in Phil. Sandh. Conch. 
p. 255. 

Bulinus, Adanson, teste Gra?/ Fig. Moll. An. 1850, p. 119.— 
S. Sf A. Ad. Gen. vol. ii. p. 259.— Non Bulinus. Adanson, 
teste Gray, Proc. Zool. Soc. 1847, p. 180, nee Beck in Phil. 
Sandh. Conch, p. 255 : — nee BuHnus, Sow. 

Physa, pars, and. Mantle simple edged. The shells of this 
section radicate affinity with the A. hypnorum, the animal 
of which is sufficiently distinct from the typical Physa;. The 
species in this genus are extremely difficult to distinguish, 
especially in the young state. The naturalist has to rely 
principally on the general habit, individual characters being 
subject to variation. 

236. ApLEXA AUEANTIA, n. s. 

A. t. tenui, ovatd, Imvigatd seu striis i?icrementi exillimii. 
nifidd, aurantio-corned, ad spiramfuscd ; spird parvd, in adtdtd 
semper erosd ; anfr. nrciter vii., suhplanaiis, tumidis ; apcrturd 
■satis dilatatd ; labio tenwissimo arcuato ; columella vix plicatd. 
Physa Peruviana, Mke. in Zeit.f. Mai. 1850, p. 163, no. 6 :— 

P. P. C. Cat. Prov. : non Gray, Spic. Zool. p. 5, pi. 6, f. 10. 



180 



MAZATLAN UNIVALVE9 



This fine species, which, is generally named P. Peruviana in 
collections, is quite distinct from the types in the Br. Mus. It 
much more nearly approaches A. Maugerte, which is believed 
to be a Caribbsean species, (not Californiau, as stated by 
Woodw. Man. ii. 171.) It differs in shape, which is never so 
elongated, and in colour which is almost always orange horn, 
with a tendency to darker shades, iu rays, below the suture. 
Shell swollen, thin, glossy, with an extremely thin coliuneUar 
lip, projecting beyond the aperture, and indented at the base 
of the body whirl. The length of the spire varies La different 
specimens, as does also the amount of convexity. The true 
A. Peruviana has a very prominent apex, with shoiddered, 
swollen body whirl. Allowance must be made in the following 
measui-ements for the constant erosion of the apex. A slender 
specimen measures long. 1'23, long. spir. '27, lat. '63. 
A sMoUen sp. „ 1'25, „ '24, „ "7. 

The largest specimen must have measured 1"43 : mean div. 60". 
Sab. — Mazatlan ; not common : L'pool Col. 

Tablet 815 contains 5 sp. slender.— 816, 5 do. swollen.— 817, 
5 do. normal state. — 818, 5 do. dark variety, approaching A. 
Maugerse in texture. — 819, 2 sp. of distorted growth. 

237. Aplexa elata, Gotcld. 
Physa e., Gould Cal. ^ Mcx. Shells, p. 6, pi. 14, f. 4. 

It is almost impossible to draw the line between this species 
nnd the yoimg of A. aurautia. Nevertheless, as a vast number 
of this sliell were sent, and very few of the other, it is presumed 
that it is adult. It differs considerably from the adult form of 
A. aurantia, being very much smaller, thinner, more pointed, 
of a light horn colour, with the whirls extremely smooth, and 
the apex never eroded. In shape it is more like A. Maugera?. 
Exactly at the suture there is generally an iU-defined line of 
lighter colour vdth. one of darker colour below. It varies 
somewhat, like the last species, in the comparative length of 
the spire. An unusually large specimen measures long. 1'08, 
long. spir. '28, lat. "5, mean div. 50°. 

ITab. — Lower California, 3fajor Rich. — Mazatlan ; very com- 
mon ; L'pool Col. 
Tablet 820 contains 10 sp. normal state.— 821, 6 do. more 

swoUen. — 822, 9 do. colour approaching A. aurantia. — 823, a 

distorted sp. slightly angled at the suture. 



MAZATLAN UNIVALVES 181 

Genxts PLANOEBIS, auettard. 

238. Planoebis tumens, n. s. 

P. t. rapide tumente, parva, corned sew ritfo-fuscd ; anfracti- 
bus iv.-v., concentrice tenue striaiis, striis undulatis ; suturis 
valde impressis ; latere altera prope suturam subangulato, seu 
interdum subcarinato ; altero rotundato ; umbilico aUissimo ; 
apertura margine sinuato, latere altero supra extante, infra 
compressd, altero supra planatd, infra productd, capad, rotun- 
datd ; labio tenuissimo. 

Planorbis affinis, P. P. C. Cat. Prov. ; non C. B. Ad. in 
. Contr. Conch, no. 3. p, 44 
Planorbis tenagophilus, JMlce. Zeit.f Mai. 1850, p. 163, no. 5 : 

non nOrb., B. M. Cat. Moll. p. 25, no. 234. 

This species is so variable that it is difficult to describe it so 
as to include all the specimens and yet separate it from its 
congeners. Aberrant individuals on the one side closely 
approach P. affinis, on the other P. lentus, Bay. The three 
may hereafter be proved identical : but the general habit of 
P. tumens, as gathered [from repeated examinations of many 
hundred specimens, is sufficiently distinct from the Jamaica 
species. The whirls are more rapidly enlarging, more swollen, 
and the lip more shouldered. An unusually large specimen 
measures lomj. '63, lat. '58, alt. "17. 
Hah. — Mazatlau ; not uncommon ; L'pool Col. 

Tablet 824 contains 3 sp., deep narrow umbilicus. — 825, 5 do. 
ordinary state.— 826, 4 do. umbilical suture large— 827, 4 do. 
umbilicus flattened.— 828, 3 do. base rounded. 

Tablet 829 contains 3 sp. reddish brown var., spi'eaduag. — 
830, 3 do. ordinary state.— 831, 3 do. keeled. 

Tablet 832 contains 7 sp. distorted growth. 

Oedee THALASSOPHILA. 

Family SIPHONAEIAD^. 

Genus SIPHONAEIA, Gray. 

G-ray in Sow. Gen. part xxi. ISM.— Blainv. Diet. Sc. Nat. 

vol. xxxii. p. 207. 
Mouretia, (Gi-aij) Sow. 1835.— Trimusculus, Schmidt, 1832. 
April 1856. r 



182 MAZATLAN UNIVALVES 

This remarkable genus does not appear to be rich in species 
at Mazatlan. The magnificent S. gigas (? + characteristica), 
though traveling as far north as S. W. Mexico, where it is not 
uncommon (P. P. C), was entirely absent (adult) from this 
collection. 



239. SiPHONAEiA Lecanitjm, Phil. 

8. t. parvd, jilerumque ovata, interdum subcirculari, ad cana- 
lem projiciente ; subconicd, sett valde depressd ; cinered, fused 
varie pictd ; epidermide tenui, adhoBrente ; costis aqualiter seu 
incequaliter distantibus, subacutis sen valde rotundatis, inter- 
stitiis scepitis costulis instructis ; costis major ibus xii. -xxii. ; 
costis et costulis tenuissime striatis, striulis radiaiitibus, sub- 
rugulosis ; costis et margine interno interdum albidis ; vertice 
subcentrali, Icevi, planatd ; pagind \internd seu atrd, seu fused, 
rarius pallida, rarissime virescente ; margine seu irregulariter 
crenulato seu stellato ; costis rotundatis excurrentihus ; canali 
declivi. 

Phil, in Zeit. f. Mai. 1846, p. 51, no. \%.—Menl'e in Zeit.f. 

Mai. 1847, p. 177, no. 1. diagnosi aucta. — Nunc diagnosi 

valde aucta. 

It cannot be expected that any one should recognize this 
species from so comprehensive a description ; and yet any 
narrower definition would shut out shells that I am unable 
to separate from the typical fonns. In its ordinary state the 
shell is subconical, thin, with a variable number of irregularly 
disposed, rather sharp ribs, somewhat projecting, and generally 
rubbed, shewing a white surface underneath. Between these 
ribs are an equally variable number of riblets, not projecting ; 
and over the whole surface, ribs included, are microscopic 
stri;e. When the creature grows in sheltered situations, it 
spreads out, becomes flat and large, the ribs swell, become 
rounded, and develop at the margin into beautiful palmations. 
So different is this form from the usual one that if they were 
each at all constant in their characters, no one would suspect 
them of being identical. Yet the variations in each are so 
extraordinary, and the intermediate forms so numerous, that 
I have found it impossible to separate them. Often, both in 
the flat and conical forms, the riblets develop into principal 
ribs, until all are nearly of the same size. It then closely 
approximates the next species. Interior of a rich iridescent 
brown or brownish black, generally light at the margin, some^ 



MAZATtAK tJNIVALVEa 183 

times througliout. Tlie apes in the adult is always flattened. 
TTie smallest specimen found, "03 in length, has much the 
aspect of a Navicella. The apex is terminal, spiral, of a very 
few Avhirls, involute, like a tumid Planorbis, turned a little 
from the middle, away from the canal, and apparently sinistral. 
The head mark is at the opposite end of the shell. A partition 
is soon placed across the spiral part, which then drops off at a 
variable period, leaving a horse-shoe cicatrix. In the speci- 
mens examined, the angle of adherence varied somewhat, as 
did the degree of revolution of the spire. The family is thus 
separated by another character from Patellidse, in which the 
apex is never spiral, and from the true Calyptrseidse in which it 
is persistent. The first portion of the normal shell which is 
formed is smooth. Presently fine striae are developed ; after- 
wards, often quite suddenly, large ribs. There is nothing in 
the juvenile shell to shew whether it will develop into the 
flat or the conical form. The channel is not apparent in the 
very young shell ; but soon becomes developed to an abnor- 
mally large size. The largest shell of the flattened form 
(includkig palmations) measui-es long. '96, lat. '89, alt. "IS. 
A subcorneal sp. „ „ "76, „ "65, „ '24, 

The flattened form, which is rare, may be distinguished as 
S. L. var. PALMATA : t. planata, costis magnis, rotundatis, ad 
marginem projicientihus, intus cavatis, quasi palmatis. — It is 
probably the S. denticulata of J/X-e. (non Quoy Sc Gaim.) Zeit. 
f. Mai. 1851, p. 38, no. 136. 

Hah. — Mazatlan, PhOippi ; — do. Melcliers ; do. abundant; 
Upool Col. 

Tablet 833 contains the youngest specimen, Navieella-shaped, 
and an older one with the scar from the detached spiral part. — 
831), 8 sp. jun. difierent ages, with spiral part visible.— 835, 
9 sp. do. spiral part detached. 

Tablet 836 contains 3 sp. var. palmata, very few (11 + ) ribs. — 
837, 4 do. large and regular.— 838, 5 do. irregular.— 839, 4 do. 
ribs very numerous, (22,) smaller.— 810, 4 do. interstices of 
palmations slightly crenate.— 841, 5 do. interstices crenated. — 
842, 4 do. greenish tiuge.— 813, 5 do. light brown.— 844,. 4 do. 
very dark.— 815, 3 do. nearly black. 

Intermediate form ; slightly palmated margin. Tablet 846 
contams 3 sp. approaching var. palmata.— 847, 3 do. dark 
brown.— 8 IS, 3 do. white margin.— 8-19, 3 do. light brown.— 
850, 2 do chocolate colour. 



181 MAZATLAN UKIVALVES 

Ordinan/ state. — Tablet 851 contains 3 sp. liglit brown. — 
852, 4 do. darker. — 853, 4 do. whitish margin. — 854, 4 do. broad 
white margin. — 855, 4 sp. blackish brown, white margin. — 856, 
4 do. penciled.— 857, 4 do. tesseUated.— 858, 4 do. nearly black. 

Specimens shelving exterior. — 859, 3 sp. fine growth, with 
epidermis.— 860, 4 do. principal ribs few. — 861, 5 do. more 
numerous. — 862, 5 do. principal ribs scarcely developed. — 863, 
1 do. with verj- fine crowded riblets, here and there developing 
into principal ribs. — 864, 2 sp. very conical. 

Tablet 865 contains 4 sp. probably belonging to this species, 
but approaching S. sequilirata. Principal ribs scarcely traceable. 

240. SiPHONABIA ^QTJILIEATA, 71. S. 

S. t. suhconicd, ovali, regulari, liris numerosis suhrugxilosis, 
(Bqualihus, radiatim ornatd, interstitiis haud latis, Icevibus ; 
fusco-olivaced, liris altis ; epidermide tenui, adka;rente ; pagind 
interna fused, vix iridescente ; margine crenulato ; canali sicb- 
centrali, extus hand prominente. 

One specimen of beautiful growth in the Mazatlan collection 
agrees with a larger but somewhat irregular one in that of 
Mr. Cuming, in characters \\hich appear to sei)arate it from 
all varieties of S. Lecanium. Eiblets equal, interstices smooth, 
channel nearer the middle and not conspicuous either by 
swelling or si)ecial marking outside. The Mazatlan specimen 
has much broader interstices thau that of Mr. Cuming ; but as 
the riblets are bifurcatmg, it is probably not fully grown. 
There is no trace of striula?. The examination of more speci- 
mens may possibly merge it into the polj-moi-phous S. Lecanium, 
from the extreme variety of which the non-prominence of the 
oanal appears to separate it. Mr. Cimiing's specimen measures 
long. "83, lat. '57, alt. '3. 
Jfah.—G\A^ of California, Lieut. Shipley. — Mazatlan ; 1 sp. 

only ; Upool Col. 

Tablet 866 contains the specimen. 

241. SiPHONABIA sp. ind. 

Tablet 867 contains a very young specimen, "07 by '05, of 
Navicella shape, with a large spu-al apex, extremelj' thin, and 
evidently belonging to a very- much larger species than S. 
Lecaniiun, possibly to S. gigas. 
Hah. — Mazatlan ; 1 sp. in shcU washings ; L'pool Col. 



MAZATLAN UNIVALVES 185 

Subclass PEOSOBEiJNCHIATA. 

In those families in wliicli the first whirls are abnormal 
as compared Avith the rest, as compared with the rest, these 
are called the nucleus, although they may be more than the 
part so formed in the egg, and their first whirl the apex. 
The measurements marked dlv. represent the mean divergence 
of the outlines of the spire. 

Oedee HETEEOPODA. 

Family lANTHINIDiE. 

This aberrant group is ranked with Carinaria in the Subclass 
Heteropoda by H. Sf A. Adams, Gen. vol. ii. p. 85 ; between 
Scalaridee and Stylinidaj by PhiUiipi, Handh. Conch, p. 179 ; 
next to Ampullariadse, Gray, 1847 ; with the Heteropoda in 
Order Plem-obranchiata, Gray 1850 ; between Neritopsidse 
and Scalariadse, in the Suborder Proboscidifera, Gray, 1855 ; 
next to Ti-ochida?, Forbes Sf Hani. Br. Moll. vol. ii. p. 547 ; 
in the Family Haliotida?, Wbodw. Mem. pt. 1, p. 148. It has 
affinities in all these groups. The vertex is not sinistral as in 
Pyramidellidse ; but dextral, fixed slanting from the future 
axis of the shell. 

Genus IANTHINA, Lam. 

It is necessary that more materials should be collected, and 
the animals observed, before a decided opinion can be expressed 
on the species of this genus. Some would reduce most of the 
forms to one or two species, Dr. Gray even hazarding the 
conjecture that the two forms usually found together (I. fra- 
gilis and I. prolongata) are the sexes of one species, (B. M. Cat. 
D'Orb. Moll. p. 35.) Mr. M'Andi-ew however found them in 
the Canaries separate, and miles apart. Others will believe 
that many difierent species have been confounded. In the ab- 
sence of information respecting the animals, it has been thought 
best to describe the Pacific species as distinct ; although it is 
highly probable that they may hereafter be identified with 
those from the W. Indies. The smaller Atlantic form is repre- 
sented, in the Pacific waters, by the beautiful I. bifida, Nutt. 
from the Sandwich Islands. 

^42. Ianthina STEiULATA, nom. prov. 

I. t. " I.fragili" simillimd ; nucleo Jiatid valde olliqtie sito, 
anfractihus iv., globoso, apice planato, suturis nullis ; anfracti' 



186 MAZATLAN UNIVALVES 

bus primis lirvlis concentricis acntis pulcherrime insti'vctjs, 
postea lineas incrementi monstrardibus ; Uneis spiralihtts jjIus 
minusve distinctis ; angulo mediano distincto ; superne pallidis- 
simd, inferne violascente ; columella tenuisstmd, plica acuta 
instructa, ad hasim plus minusve extorta ; lahro plus minusve 
sinuato, sinu angulato ; labio vix projiciente, tenuissimo. 

Comp. lanthina fra<;ilis, D'Orb., B. M. Cat. Cuba Moll. p. 23, 
no. 258 -.—B. M. ^Cat. B'Orb. Moll. p. 36, no. 316 -.—B. M. 
Cat. Can. Moll. p. 15, no. 107 •.—( = 1. communis, Lam. An. s. 
Vert. vol. ix. p. 4, pars.) 

This shell may hereafter prove to be identical with one of 
the various Atlantic species. There are two forms called 
I. fragilis from the W. Indies ; one agreeing with this in the 
separation of colours and sharp columella, but with more pink 
in the violet tinge ; the other agreeing in tint, but with the 
colour diffused and the columella coarser. All differ essentially 
from the British I. communis, (of which there are two very 
different ? varieties) in the very fine concentric liration of the 
upper whirls, and in the character of the nucleus. Tliis, in 
I. communis, is sunken, but not flattened at the apex ; in the 
tropical species it is rather prominent, but flattened at the top. 
It is not so horny as in the next species, and is always persis- 
tent. The shape is tolerably constant ; but the amount of 
sinuation in the outer lip somewhat varies. The very young 
shell is globular, without angular keel. Long. "78, long. spir. •44, 
lat. 1-, div. 100". 

JECab. — Mazatlan ; abundant ; L'pool Col. 

Tablet 868 contains a very young sp. '(M across, broken, but 
shewing the transition between the oblique and straight por- 
tions.— 869, a young sp. with fry adhering to the suture.— 870, 
3 sp. depressed form.— 871, 5 sp. normal state, jun.— 872, 5 do. 
adult.— 873, 4 sp. spire elevated.— 874, 3 sp. basal angle pro- 
duced.— 875, 4 do. shoulder cui-iously swollen.— 876, 7 do. 
broken and mended by the animal. 

242, b. Ianthina striulata, var. contobta. 

J. Utriulata, columcUd maxime contortd, ad basim productd, 
rq/lexd, sinu magna, hand angulato. 

This shell when taken alone would certainly be regarded as 
a distinct species : but as several specimens of I. striulata shew 



MAZATLAN UNIVALVES 



187 



somewkat of an approach to it, it is presumed (in the absenoe 
of knowledge of the animal) to be an aberrant variety. 
Hah. — Mazatlan ; extremely rare ; L'pool Col. 

Tablet 877 contains the extreme specimen, and a younger 
one, intermediate. The larger sp. is but slightly waved in the 
outer lip : another, however, with the same twisted columella, 
presented the ordinary indentation in the labrum. 

2d<3. Ianthina decollata, nom.prov. 

I. t. glohosa ; spira plus minusve extante, pallide violacea ; 
anfractu ultimo pallidissimo, hasini versus violacea ; apice 
cornea, deciduo ; nucleo ohliquo, haud extante ; sutura profunda ; 
lahro varie sinuato ; columella vix contortd ; labia liaud par- 
recto, umhilicum sccpe tegente. 

Comp. Ianthina globosa, Swains. Zool.Ill. vol. ii. pi. 85, fig. med. 
Comp, lanthiaa prolongata, D'Orh., B. 31. Cat. Cuba Moll. 

p. 23, no. 259 ; B. M. Cat. D'Orb. Moll. p. 35, no. 317 ; non 

Desh. in Lam. An. s. Vert. vol. ix. p. 5, no. 3. 

This shell is most closely related to the West Indian species, 
differing from the specimens examined simply in colour, which 
instead of being equally diffused on the sheU, is confined to 
the base and spire. It differs from I. prolongata of the Medi- 
terranean and Canaries in the very slight contortion of the 
columella, which in the Europsean species resembles that of 
Lymnaea (Desk.) If the I. globosa of Swains, represents the 
W. Indian shell, and not the I. prolongata, as Desh. and Gray 
suppose, this shell may prove identical with it, when more 
specimens have been found from other localities. The Mazat- 
lan specimens, though very few, differ considerably in the 
greater or less exsertion of the spire, inflation of the shoulder 
and base of the body whirl, and conceahnent of the umbilicus. 
The sinuation of the outer lip varies not only in diflerent speci- 
mens, but in the same shell at different periods ; being some- 
times scarcely waved, at others strongly angulatcd as in I. fragi- 
lis, sometimes with a semicircular medial sinus. The nucleus 
is sunken, rather oblique, with the apex horny and always de- 
collated. In I. prolongata, it is exsertcd and persistent. The 
largest sp. measures long. 1"02, long.spir. '3, lat. "87, div. 105°. 
A swollen sp. measures „ '83, „ '13, „ '81, ISC. 

Bai.— Mazatlan ; with I. striulata, extremely rare ; L'pool Col. 

Tablet 878 contains 3 specimens. 



188 MAZATLAN T7NIVALVE3 

Oedee LATEEIBEANCHIATA, Clark. 

Family DENTALIADiE. 

Genus DE:?^TALnBI, Linn. 

The fullest account of tke animal of this remarkable tribe, 
will be found in Clarlc, Moll. Test. Mar. Brit. pp. 225—238. 
It has only a faint analogy -vvith Fissm-ella ; and differs so 
much from even the most aberrant of the Scutibranchs that 
the Order, proposed by Clark, is adopted. There are many 
points of analogy with the Lamellibranchiate Mollusca, and 
some with the Annelids. Individuals appear to be very rare 
at Mazatlan, perhaps in consequence of the scarcity of For- 
aminifera, on which these blind, almost headless creatures 
voraciously feed. 

244. DENTALIUil LlEATUil, 11. S. 

D. t. solidd, alba, tereti, liris longitudinalihus tenuissimi'S 
creherrime indicia ; liris in juniorem circiter xii., in adultam 
circiter xxx., acutis, haud cequalibtts ; parum arcuatd, aperturd 
hranchiali simplici. 

One perfect, though rather small, specimen was found en- 
tangled in the byssus of Modiola capax ; fragments occurred 
of a much larger size. Long. '25, lat. 'Oil— 'OS. 
Sab. — Mazatlan ; off" ]\Iodiola capax, Chamse and Spondyli, 

very rare ; Z'pool Col. 

Tablet 879 contains the perfect specimen, a small do. wedged 
in the mouth of Tri\na sauguiuea, and a fragment of a large 
one, '065 across. 

245. Dentalium hyalixum, P/iil. 
Zeit.f. Mai. 18i6, p. 55, no. 2". 

Tablet 880 contains a minute shell of a hyaline texture, with 
an opaque line running along the inner curve, which may be 
accidental. It probably belongs to the above species des- 
cribed by Philippi from Mazatlan, although that is said to be 
"versus apicem tenuissime striata," while this, which is ex- 
tremely young, is smooth. Long. '07, lat. "01 — "025. 
Sab. — Mazatlan ; 1 sp. off Spondylus calcifer ; L'pool Col. ' 



MAZATLAN UNIVALVES 189 

246. Dentalitjai coebugatttm, n. s. 

D. t, alhiclo-corncd, subdiaphanu, pantm arcuata, gracili, 
superjicie concentrice irregiilariter corrugata, rugulis minimis, 
confertissimis ; apertiird hranchiall simplici. 

One very young specimen only was fonnd of tliis species, 
remarkable for its concentrically -vn-inkled surface. Long. '05, 
lat. • 005— -01. 
Hab. — ]Mazatlan ; 1 sp. off Spoudylus calcifer ; L'pool Col. 

Tablet 881 contains the specimen. 

24,7. Dextalitjm; ? peetiosum, Kutt. (teste Hds.) 

Tablet 882 contains a fragment of a smooth species. It is 
affiliated to the above, because a specimen in Mr. Darbisliire's 
collection, brought along with Lyonsia diaphana, seems to have 
come from Mazatlan. This latter, a very small one for the 
species, measures long. 1'56, led. '05 — '15. 

Hab. — ? Mazatlan ; extremely rare, off Chama ; L'pool Col. 

Oedee SCUTIBEAJS^CHIATA, Gf-ra?/. 

Scutibranchiata + Cj'clobranchiata + Pectinibranchiata (pars) 
Cuv. 

Family CHITONIDiE. 

Our knowledge of this most aberrant family is verj- incom- 
plete. Many genera have been proposed by Dr. Gray in the 
Proc. Zool. Soc. 1847, pp. 63, 126, and others by H. Sf A. 
Adama, Gen. vol. i. pp. 467-484 ; and others by Dr. Shuttle- 
worth of Berne. This fullest account of their physiological 
structure will be found in "Middendorff's Malacozoologia 
gia Rossica, St. Petersburg, 1847, Part I ; Beschreibung und 
Anatomic ganz neuer oder fiir Russland neuer Chitonen ;" in 
which 152 large 4to pages, and 14 plates are devoted to the 
elucidation of 21 species. Additional information is given in 
his " Iteise in den Ausnersfcn Nor den und Osten Sibinens, 
Part II. St. Petersburg, 1851." pp. 163-183, pi. 13-15.— Most 
of the Mazatlan species are extremely small. None of them 
are known to inhabit any other district, except Lophj-rus 
sanguineus, about which there is still some doubt. Throughout 
the world, they appear to be among the most local of sheUs, 



I90 



MAZATLAN TJNIVALVES 



In the following descriptions, as far as practicable, the terms 
are employed as proposed by Midden dorfF, 3Ial. Boss. p. 36. 
By thejuffum is meant the ridge running along the middle of 
the valves ; the mucro is the apex on the posterior valve : the 
valve-lohes are the prolongations of one valve which fit under 
the uext ; the sinus lies between them. 



Genus LOPHYEUS, Poll 

H. Sf A. Ad. Gen. vol. i. p. 469. — Hadsia + Gymnoplax, Gray. — 
Chiton, pars, auct. — Plates of insertion in denticulated lobes ; 
integument tessellated with smooth scales. 

248. LopnYETJs aeticulatus, Sow. 

Chiton articulatus, Sow. in Froc. Zool. Soc. March, 1832, 
p. 59 •.—Conch. III. no. 29, f. 18.— Zool. Beech. Voy. p. 150, 
pi. 41, f. 16. 
Lophyinis articulatus, S. ^ A. Ad. Gen. i. 470. 

The figure in the Conch. HI. is very accurate ; but that in 
Beech. Voy. represents much too strong a scvdpture. The 
Mazatlan specimens' rarely display any sculpture at all, being 
almost universally eroded, even in young specimens. The 
plainness of the exterior is however abundantlj" compensated 
for by the great beauty of the inner structure of the valves, 
which the large number of specimens sent allow to be freely 
examined. The form is sometimes broad, with nearly straight 
sutures ; sometimes elongated, with arched back, and sutures 
bent, occasionally into the form of a - — , — ' . Very rarely 
the shell is indented on each side of the jugum, rudely present- 
ing a likeness to a Trilobite. The surface of the valves, when 
perfect, is crowded with minute pustules ; diagonal lines 
scarcely marked. Colour olive green shaded into reddish 
brown at the ridge, with irregular longitudinal streaks of 
brown olive on each side : fiiint narrow rays of the same tinge 
on the terminal valves, and irregularly waved penciling over 
the surface of the diagonal areas. Inside bluish green ; valve- 
lobes long and flattened, with a broad medial sinus. The 
surface within, under the mici'oscope, is extremely finely cor- 
rugated. The margin is formed of fine, irregular plates, each 
sometimes branching into a plume ; these are interrupted in 
the medial valves by one slit on each side, in the terminal ones 
by 14—20. From these proceed rows of punctures to the axis 



MAZATLAN UNIVALVES 191 

of the shell ; in the young state visible within, in the adiilt 
concealed, but generally traceable in the eroded surface. At 
the junctions of the valves, close above the valve-lobes, may 
be seen rows of large open cells, with smaller ones above, 
somewhat resembling the parenchyma of a leaf cut across. 
Along the sinus is another row of plates as in the margin. The 
structure of the shell presents many points of analogy with the 
Cirripedes : as does the animal with others of the Articulata. 
The integument is crowded with very deciduous, hard, green 
scales, sharply jointed, having 3 sides, of which one is corru- 
gated, the others smooth. They are somewhat of the shape of 
a pistachio nut. The following measurements are not perfectly 
exact, in consequence of the curvature of the specimens. 

A broad specimen measures long. 2 '7, lat. 1'7, div. 12(y. 

The largest specimen „ „ 4-2, „ 2-2, „ 105". 

Sab. — San Bias, under stones, Beechey. — Mazatlan ; abundant, 

but much worn ; L'pool Col. 

Tablet 883 contains 4 sp. in the usual condition. — 884, 1 do. 
very perfect. — 885, 3 sp. broad form. — 886, 2 sp. elongated. — 
887, 2 sp. surface eroded, displaying the inner structure. — 888, 
1 sp. with very irregular margins, and Conia attached. — 889, 
1 sp. obscurely trilobed.— 890, 2 sp. with head valves abnor- 
mally large, perhaps from limpets attached. — 891, valves of 
very young sp. — 892, 2 sp. valves separate to shew structure. 

Tablet 893 contains an extremely young specimefl, "16 in 
length, which probably belongs to this species. The valves 
are more sti'ongly pustulose, and the marginal scales much 
larger in proportion than in the adult. There is also a row of 
hairy processes at the mantle margin, below the scales, which 
may be connected with the gills. It has more the aspect of 
C. lajvigatus, Soto. Proc. Zool. Soc. 1832, p. 59 : Couch. III. sp. 
30, f. 18*, which is from the same locality, and may prove to 
be only a variety of C. articidatus. 



249. LOPHYRUS ALBOLINEATUS, Brocl. ^' Sow. 

Chiton albolineatus, Zool. Journ. vol. iv. p. 308. — Soto. Conch. 

III. sp. 42, f. 39.— Zoo/. Beech. Voy. p. 149, pi. 40, f. 4.— JSre. 

Conch. Ic. 
Lophyrus albolineatus, M. ^ A. Ad. Gen. i. p. 470. 

This beautiful species is remarkable for the different appear- 
ance of valves on the same specimen, which may be either 



192 MAZATLAN UNIVALVES 

albolineate or quite black. Normally there is a black line on 
the ridge, bounded by two white ones ; diagonal areas and 
terminal valves white, penciled with brown in finely waved 
transverse lines. Besides the colour, shax^e and delicate tex- 
ture, it differs from the young of L. articidatus in the following 
particulars. Surface (under the microscope) regidarly granu- 
lated in diagonal rows ; granides larger in proportion. Radia- 
ting lines of punctures almost alwaj's visible within. Plates of 
insertion in simple rows, not plumed. Sinus with irregular 
transverse incisions internally. Substance of valves next the 
lobes with a row of larger cells. Scales of margin more grey, 
rounder, more deciduous. — In the young sheU, the granules on 
the diagonal areas are much larger in proportion. In addition 
are seen extremely fine striae, diagonal over the areas, longi- 
tudinal over the rest. The marginal scales are much larger in 
proportion, and are bounded by a row of gill-like hairy pro- 
ceses, as in the young of the last species. — The largest specimen 
measures long. 1"8, lat. '9, div. 115". 
Hah. — Mazatlan ; Belcher. — Do. ; rare ; L'pool Col. 

Tablet 894 contains 3 extremely young specimens, the small- 
est ■ 18 in length. In one, most of the valves are separate, 
displaying the same structure as in the adult. The mantle 
shews clearly the marks of insertion ; and, with the dried 
remains of the animal, is so transparent that the lingual ribbon 
is clearl;f traceable within, 'Ol by '0075 in. 

Tablet 895 contains thi-ee specimens : the largest, one with 
the margin perfect, and one with black valves intercalated. — 
896, 2 sp. with the valves separate, and 2 nearly black valves 
to shew structure. 



250. LOPHYETJS STHIATO-SQTTAMOSTTS, n. S. 

L. t. subrof/icndatd, depi'essd (ad anqulam 140°^, pallidefu.sco- 
olivaced ; valvis totd superjicie dense granulatis ; areis laterali- 
bus satis distinctis ; valvis latis, vix curvatis, vix muo'onutis ; 
jugo vix distincto, tenmssime longitudinaliter stn'ato ; marginihus 
lateralihls 2}lanatis : mucrone superim'e, vix distincto ; Umbo 
pallii squamis solidis, vvalibus, magnis, hand confertis, instructo, 
squamulm cujusque dimidio alie striata ; tnarginibus valvarum 
serratis,fissv,ris in valvis intermediis und in latere utroque,in 
valvis tcrminaUhus circiter xii. ; valvarum lobis magnis, valde 
arcuatis. 



MAZATLAN UNIVALVES 193 

The serrations of the margin in the only perfect specimen 
found are distinctly visible through the dried cuticle, as they 
are also in some dead valves ia other respects agreeing with 
the shell. Below the large scales of the mantle margin appears 
a row of gill-like flattened hairs, as in the young of L. articu- 
latus and albohneatus. Long. '17, laf. '12, alt. 'Odi. 

Hab. — Mazatlan ; 1 sp. off Spondylus calcifer ; L'poo^ Col. 

Tablet 897 contains the specimen. 

Genus PTONICIA, Grat/. 

Proc. Zool. Sec. 1847, p. 65— iT. ^ A. Ad. Gen. vol. i. p. 473.— 
Chiton, pars, auct. Plates of insertion as in LophjTus : mantle 
smooth. 

251. ? TONICIA FORBESII, 71. s. 

? T. t. ovatd, subelevata (ad angulam 115"^ brunned, olivacen 
varie pictd ; valvis mtermediis mucronatis, sulcis injugo ^-for- 
mibus a mucronibus projicientibus decwrrentibus ; lineis diagon- 
alihus valde tuberculaiis ; areis lateralibus sparsim punctafis, 
ad valvarum inierstitia tuberculato-corrugaiis ; areis centrali- 
bus rugis curvatis diverg&iitibus, in valvis terminalibus circitej' 
xiii. ; mucroiie conspicuo ; limbo ^>aZZ«z suhlcBvi, ienuiori ; 
valvarum lobis intus declivibics, sinu alto, lato ; jugo intus roseo : 
marginibus valvarum et sinus dense set'raiis,Jissuri.'i in valvis 
intermediis und, in latere uiroqiie, in valvis terminalibus rugis 
externis convenientibus. 

Two specimens were found of this very beautiful species. 
which is dedicated to the memory of the learned and deeply 
lamented Prof. E. Forbes, whose promised assistance, had lie 
lived, might have prevented many errors in the present work. 
Neither of the specimens shew any trace of imbricated scales, 
though they may possiblj^ exist. The structure of the marginal 
plates closely resembles that of Lophyrus albolineatus. Lonq. 
•78, [lat. -45, alt. 'U. 

ifai.— Mazatlan ; extremely rare ; L'pool Col. 

Tablet 898 contains the finest specimen ; the other is in 
Mr. Darbisliire's cabinet. 

April 1856. s 



194 MAZATLAN UNIVALVES 

Genus LEPIDOPLEUEUS, Risso. 

H. Sf A. Ad. Gen. vol. i. p. 471.— Ischnocliiton, Gray, Proe, 
Zool. Soc. 1847, p. 126. Mantle scales very minute, grooved : 
insertion-plates thin, smooth-edged. 

252. Lepidopleueus sanguineus, Rve. 

Chiton sanguineus, Rve. Concli. Ic. pi. 17, f. 98. 

Comp. Chiton limaciformis, Soto. Pruc. Zool. Soc. 1832, p. 26 : — 
Co?w//. III. sp. 58, f. ■iS.—Rve. Conch. Ic. pi. 8, sp.'42. (Co- 
lumbia, Sow. : Inner Lobos Is., Peru, and Guacomayo, under 
stones at low water, Cuming.) 

This is probably not the Ch. saugoineus of Guilding, from 
St. Vincent's, which is quoted by Eeeve in the Conch. Ic. ; 
and is certainly not the Ch. sanguineus of Dr. Cutting, from 
Barbadoes, in the Bristol Museum. It is however identical 
with the specimens in the Cumingian collection, and most 
cleselj' resembles Ch. limaciformis. There may be a difference 
in the integument, whicli the imperfect state of the specimens 
has failed to display. The Mazatlah shells are more generally 
tuberculated on the terminal valves than on the tj^ical speci- 
mens of the species. 

The mode of attachment is quite different in this shell from 
that of Lophj'rus. The valve margin has an outer and an 
inner rim ; the outer being a simple continuation of the exter- 
nal shell layer ; the inner being a white, sharp ridge, cut by 
10—14 slits in the terminal valves ; so as to give the appear- 
ance of a lip with a row of incisor teeth within. The central 
valves have one slit. The radiating punctui'cs are elongated. 
Inside rose coloured ; outside brownish pink, or dark olive 
green, or brown, or .yellowish irregularly spotted with green. 
Surface deeply furrowed with irregidar longitudinal lines, 
waved at the sharply angular diagonal lines. The terminal 
valves are tuberculose, finely so above, coarsely below. Interior 
surface finely coiTugated and ridged for the muscular attach- 
ments. V^alve lobes small, arched ; sinus very large. The 
valves are easily loosened from the membrane, which is 
generally thin and smooth, sometimes with an irregiilar whitish 
deposit, apparently not of organic matter. Long. 1'04, lat. "4, 
dh. 105". 
Hah. — Mazatlan ; very rare ; L'pool Col. 

Tablet 899 contains 4 sp. various colours.— 900, 2 sp. opened 
to shew the valves. 



MAZATLAN UNIVALVES 195 

253. Lepidopleurus clatheatus, n. s. 

L. t. subrofundatd, depressa, (ad angulam l^QfJ fusco-oliva- 
ced ; valvis latissimis, marginibiis lohatis, interstitiis subrectis ; 
valvis iyitermediis, injugo et (plus minusvej totd superfine granu- 
latis; costis duahiis, tubercuUs prcevalidis munitis, und diagonali, 
alierd supra marginein decurrente ; areis lateralibus parvis, 
gramdatis ; areis centralibus clathris iv. utroqiie in latere 
longitudinalihus munitis, clathris tuberculatis, interstitiis gran- 
ulatis ; valvd untied costibus radiatitibus circiter xi. rotundatis, 
subtiiherculatis ; limbo pallii latissimo, squamulis minimis, 
molUbus, conferto ; marginibus valvarum simplicibus, antico 
Ussuris ix. ad castas hand convenientibit^, testa externa, quasi 
subgnmdd, circumeunte. 

One very small specimen was discovered on a stone to wHch 
a Crucibulum had been attached, beautifully perfect except in 
the loss of the anterior valve. A dead anterior valve was found 
of a much larger specimen, displaying a marginal structure like 
that of L. sanguineus. The shell is remarkable for the strong 
bars across the ventral areas, and the stout rows of tubercles 
which run, the one diagonally, the other along the interstitial 
margin. The mantle is very broad, and crowded with minute 
scales. Long. -17, lat. '12, alt. •02. 
JIab. — Mazatlan ; imder stones, extremely rare ; L'pool Col. 

Tablet 901 contains the specimen. 

254. Lepidopleueus BCLLATrs, n. s. 

L. t. subovata, elevatd (ad angulam 110",^ olivaced ; valvis 
intermediis lineis diagonalibus bullis extantibus arnatis ; areis 
lateralibus angustissimis, tuberculatis, interdum bullis munitis ; 
areis centralibus lineis tubercularum, in titrdque parte circiter 
vu., lineis diagonalibus perpendieularibus : interstitiis ubique 
granulatis ; valvis terminalibus lineis bullarum radiantibus 
circiter xi., mucrone suhconspiciio ; limbo pallii lato, pilulis 
minimis in.strucfo ; valvarum lobis biangulatis, sinu alto ; 
7narginibus valvarum simplicibus, in valvis intermediis fissurd 
uno, terminalibus circiter vii., margine externo tegente. 

One fresh specimen (somewhat crushed in extraction) and a 
few perfect valves were found of this species, which is charac- 
terized by the very strong row of tubercles, (like pebbles) which 
lie on the diagonal line ; by the rows of somewhat strong tuber- 
cles on the central area, running perpendicidarly from the 



196 MAZATLAN UNIVALVES 

diagonal towards the jugum ; and the granules over the whole 
surface, somewhat corrugated on the jugum. The internal 
plates of all the valves have an external projection from the 
outer surface, as in L. sanguineus. Long. "17, lat. '12, alt. '03. 

Sab. — Mazatlan ; oflf Spondylus calcifer, extremely rare ; 
L'pool Col. 

Tablet 902 contains the sp. and 2 odd valves. 

254, h. Lepidoplettkus bullatus, var. calcifeetjs. 

L. 1 bullatus, areis lateralibus 'tuberculatis, sine hullis, lined 
diagonali quasi calculis instructd ; areis centralibus lineis tuber- 
cularum irregularibus, tuherculis inmoribus ; pilidis pallii 
majoribus, co nfertissimis. 

Tablet 903 contains one specimen which presents the above 
diJBFerences. Whether they be specific, cannot be determined 
without other and older specimens. 
Hab. — Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 

255. ? LEPiDOPLErrBTJS Mac-Andeei, n. s. 

? L. t. '' Lophyro stnato-sqttamoso" valvis et Umbo pallii fere 
omnino simulante, sed marginibiis valvarum aciitis, haudserratis. 

A smashed specimen in fresh condition was found on a 
Spondylus, not distinguishable externally from Loph;\TUs 
striato-squamosus, but unexpectedly presenting the sharp in- 
sertion-plates of Lepidoplcurus, at the same time that the scales 
agreed exactly in the remarkable character of the former 
species. Not daring to build on such imperfect data, I sus- 
pended my judment -. but when examining some specimens of 
Margaritiphora Mazatlanica in the collection of T.NuttaIl,Esq., 
I was fortunate enough to discover between two lamina; a per- 
fect little Chiton, which on examination tui'ned out to be exactly 
identical with the smashed specimen from the Spondylus. 
Having loosened a terminal valve, and subjected it to repeated 
examinations imder a half-inch acliromatic, I am unable to dis- 
cover any trace of serration,* while in L. striato-squamosus it 
is unmistakably evident. In the absence of further evidence, 
we are obliged to conclude, either (1) that the same species 

* In oiamining young Chitons, it is necessary to guard against being misled 
by the giU-Uke lamina, which, passing over the insertion-plates, is apt to give 
them (under a low magnifier) a serrated appearance. 



MAZATLAN UNIVALVES 197 

may adopt both forms of marginal insertion at different periods 
of growth, which is contrary to our observation in the young 
of other species ; or (2) that a different creature, belonging by 
its plates to one genus, puts on the exact appearance of a species 
in another, even to the very conspicuous scales, which are for- 
bidden by the diagnosis to Lepidopleurus, and are also striated 
which is equally forbidden in Loph3Tus. Under either suppo- 
sition, it would appear that we have not j'et attained a correct 
knowledge of the principles of division to be adopted in this 
most remarkable family". Long. "13, lat. '08, alt. .025. 
Hab. — Mazatlan ; on Spondylus calcifer, extremely rare ; 

L'pool Col. 

Tablet 904 contains the perfect specimen, kindly presented 
by T. Nuttall, Esq. Of its habitat nothing is certainly known. 
The Avicula to which it adhered was exactly like the Mazat- 
lan shells ; and there were also found on its surface several 
specimens of Septifer Cumingianus, and two of a species of 
Caecum, both identical with those from Mazatlan. 

256. .?Lepidopleueus Beanii, n. s. 

1 L. t. ovatd, elevatd fad angulam Y\£P), fusco-olivacea, seu 
alhido ccBruleoque maculatd ; valvis intermediis valde mucrona- 
tis, interstitiis curvatis, marginihus suhrotiindatis ; valvd pos- 
tica depressa, excavatd, mucrone minimo, superiore ; jugo et 
areis lateralihus indistinctis : stiperjicie tot a granulis instructd, 
et punciulis minimis covfertim ornatd : valvaruni lobis magnis, 
curvatis, sinu planato ; marginihus acutis, Jissuris circiter x. 
valvis terminalihus, tmd in utroque latere, i)ttermediis ; margini- 
hus externis prominentihus ; limho pallii piluloso, spinulis par- 
vis, erectis, planatis. 

Differs from L. Mac-Andrei in being longer, with the valves 
mucronated and roimded at the extremities, the posterior 
being hollowed out, and the rest much elevated, without con- 
spicuous middle portion or lateral areas. The only perfect 
specimen found (on Acmrca fascicularis) displays no trace of 
solid scales. The account of the interior is taken from a large 
central and small anterior valve supposed to belong to this 
species from their agreement in other respects. Long. '23, 
lat. ■ 13, alt. -04. 
Sah. — Mazatlan ; extremely rare ; L'pool Col. 

Tablet 905 contains the perfect specimen off Acma;a, and 
the two valves. 



198 StAI^ATLAN trKIVAI,V£S 

Gi;nus chiton, Linn. 

Chiton, pars, auci. — H. ^- A. Ad. Gen. vol. i. p. 474.— Acan- 
thopleura, Guild. ; Gray in Froc. Zool. Soc. 1847, p. 67. — 
Margin spinose : insertion-plates in terminal valve ruany- 
lobed, in middle valves bi-lobed. 

257. CniTox flavescens, ??. s. 

Ch. t. ovafa, valde depressd (ad angulam 150*^ jlavida, 
auranfio maciilata ; valvls latis, marginibus suhrotundatis, 
interstitiis curvatis, valde nmc?'Oiiatis ; areis lateralihus et jugo 
indistinctiorihus ; mucrone parvo, superiore ; tot a superficie 
granulis rugulosis confertim instruct a, haud, punctulatd ; limho 
pallii crasso, suhlcevi, ad marginem spinulis tenuibus, erectis, 
planatis histructd ; valvarum lobis, magnis, arcuatis, sinu 
maximo ; marginihus valvarum intermediarum fissurd duas in 
lohas divisis, quarum iina 'jiarva, lineis pimctorum utrdque in 
parte adjugum decurrentibus ; valvarum uUimarum marginihus 
suhacutis, fisswris circiter x. 

This is the least uncommon of the small Chitons, six speci- 
mens having been found of it. It is distinguished by its yellow 
colour, great depression, and small strong mantle margin, 
without covering, except at the margin where a ftne row of 
transparent flattened hairs may be seen. The smaller lobe on 
the margins of the inner valves is bounded by two rows of 
holes which proceed to the jugum. Long. "16, lat. '11, alt. '3. 
Another specimen, rolled into a ball, is larger. 
ffah. — Mazatlan ; on shells, very rare ; L'pool Col. 

Tablet 900 contains the largest specimen ; another in situ 
on a broken crevice of CrepidiUa ; and 2 separate valves. 

Genus ACANTHOCHITES, Bisso. 

Gray, Froc. Zool. Soc. 1847, p. 66 : H. 4' A. Ad. Gen. vol. i. 
p. 482.— Chiton, pars, auct. Mantle -R-ith tufts of bristles. 

258. AcANxnocHiTES Abeagonites, n. s. 

A. t. elongafd, elevatd (ad angulam \W), pallido-fuscd, 
olivaceo et rosea variepictd : valvis intermediis valde mucronaUs, 
interstitiis a mueronibus valde divcrgentibus ; jugo lato, pallida. 



^- MAZATLAN UNIVALVES 199 

tenuissime longitudinalUer granulato-striato, transversim minu- 
tissime cormgato ; areis lateralihus indistinctis ; mperficie 
tota valde granulatd, tuhereulis sphceroidalibus et granulis 
catenatim in lineis a jugo suhdivergentihus elegantissime in- 
structa ; mucrone subconsjncuo, subcentrali ; intus rosed seu 
alha ; marginibtis acutis et lobis valvarumnon sej^aratis, mag- 
nis,fi^surd in utroque latere una, lobis angT.latis, sinu maximo, 
X>lanato ; ad jugum temdssime corrugatd, ad mucronem lamin- 
atd ; valvd posticd hexago7iali, duabics fissuris ad terminum 
divisd ; limbo pallii spictdis erectis translucidis copiose ornato ; 
postice, antice, et adsuttcras, spicularum quasi acicularum cristis 
pulcherrime munito. 

"WTiether the varied colouring of tliis shell, its elegant sculp- 
ture, the bird-like form of the medial or hexagonal shape of 
the bifissured terminal valves, or the adornment of the mantle 
with transparent needle-like hairs, rising now in tufts, now in 
irregular crystals, be examined under the microscope, it would 
be difficult to find any shell of such surpassing beauty. Only 
one pei'fect specimen was found, but fresh valves belonging to 
several other individuals were detected among the Spondylus 
washings. The valves in the same shell greatly differ in colour, 
as in L. alboliueatus. The posterior valve is peculiarly exqui- 
site in its form, colour and sculpture. There is considerable 
variation in the size of the tubercles, and in the striation of 
the jugum. The outer margin does not enclose the plates of 
insertion, as it does in Lepidopleurus. Long. '16, lat. '06, alt. "02. 
^aJ.— Mazatlan ; oiF Spondylus calcifer ; extremely rare ; 

L'pool Col. 

Tablet 907 contains the perfect specimen and 4 valves. 

Family PATELLID^. 

Genus PATELLA, Unn. 

As the shells in this genus can scarcely be distinguished 
from those of Acma?a, the location of many of the following 
species in this and the next family is doubtful. 

259. Patella Mexicana, JBrod. Sf Sow. 

Zool. Journ. vol. iv, p. ^Q^.—Menke in Zeit.f. Mai. 1851, p. 37, 

no. 132. 
=Lottia gigantea, B. M. : Gould ms. 
= PateUa maxima, B. M. Cat. JD'Orb. Moll. p. 53, no. 449. 



200 MAZATLAN UNIVALVES 

Shell extremely large ; white, or of a yellowish, or greenish 
tinge, occasionally orange ; with a broad marginal band of a 
semidiaphanous hue, very conspicuous in the young shell. 
Muscular scar in adult raised, irregularly lobed and corrugated. 
The outside is frequently covered with Algx and bored by 
Lithophagi. Its surface is a favourite place of adherence for 
smaller limpets. In the young sheU may be traced about 10 
very indistinct principal ribs, with a profusion of radiating 
lirulaj. These however very soon disappear. The yoimgest 
ascer tamed specimen measures long. 1' 65, lat.l'4i, alt. '42. 

The:iargest sp. „ „ 9-2, „ 6-9, „ 4-5. 

A flatter do. „ „ 9', „ V'!, „ 3-6. 

JTab. — Mazatlan, Beecheys Voyage. — Do., Menke. — Do. ; 

abundant, L'pool Sf Havre Coll. — Monterey, Col. Jewett, 

(Gould ms. : uon ]Viitt.)—7sijtsi, Peru, Z)' Orhigny. 

Tablet 908 contains 3 young sp. different ages. — 909, 1 sp. 
finely grown, adolescent, margin flattened.— 910, 1 do. margin 
sharp, muscular scar thick, brownish red. — 911, the largest sp.> 
outside riddled by Lithophagi. 

260. Patella pediculus, Phil. 

Zeit.f. Mai. 1846, p. 21, no. 8. 

= P. corrugata, Bve. Conch. Ic. sp. 132, pi. 40, f. 132, a, b. (1855.) 
Comp. P. Araucana, B. M. Cat. D'Orb. Moll. p. 53, [no. 448 : 
( = however P. zebrina, var., teste Gray m loco.) 
Shell normally flat, oblong, solid, with 10 stout roimded ribs 
projecting at the margins, of which 2 arc in the axis of length 
with 4 on each side : ribs and interstices radiately striated : 
yellowish white, generally with more or less of black or brown 
tortoise-shell markings witliin, sometimes with the black be- 
t«veen the ribs as described by Phil, and Rve. Sometimes the 
shell is more rounded and the ribs rather angular, ia which 
state it might be taken for the young of P. Mexicana. Occa- 
sionally a few other intercalary ribs appear. In a very few 
unusually large specimens, the ribs are nearly obsolete at the 
margin and the shell is much lengthened. The body mark 
varies as usual ; when plain, it is gathered into points as in P. 
discors. The very young shells appear not to develop the ribs 
marginally, in which state they might be talcen for the yoimg 
of P. discors. The stout ribs of the adult shell however bear 
no analogy with the very finely marked surface of the latter 
■with its curiously puckered circum-umbonal portion. With the 



MAZATtAN tJNiVALTES 20l 

young of P. Mexicana it has mucli closer analogies. The 
largest specimens of P. pecliculus however do not at all run 
into the smallest of P. Mexicana. They have all the appear- 
ance of being old shells, with the margin narrow and the 
shape long and irregidar ; whde P. Mexicana, as it is traced 
upwards, displays a very wide semitranslucent margin, and a 
broad regular shape, with the ribs not rounded and prominent 
but simply giving an angular form to the shell. To settle the 
point satisfactorily will require a series of P. Mexicana from 
its earliest stage, as well as a knowledge of the animals. Of 
this species I have carefidlj^ examined nearly 300 specimens. 
The youngest shell that has its ribs developed and clearly 
belongs to this species is '17 long. Tablet 912 contains two 
smaller ones without distinct ribs, which probably belong to it. 
Even when very young, they are almo.st always incrusted with 
corallinous matter. The largest specimen measures ?oh(/. 1' 3, 
lat. 1', alt. '4. The ordinary size however is very much smaller 
an'd flatter. 

Hab. — Mazatlan, Philippi. — Acapidco, Eeeve. — Mazatian ; not 
imcommon ; L'pool Sf Havre Coll. 

Tablet 913 contains 3 young specimens. — 914, 3 sp. ordinary 
state.— 915, 3 do. ribs well developed. — 916, 3 do. light tortoise- 
shell withia. — 917, 3 do. dark tortoiseshell. — 918, 3 do. broad 
variety. — 919, 4 do. ribs numerous. — 920, 4 do. elongated, ribs 
small. — 921, 1 sp. abnormally elongated, with very small ribs. — 
922, Patella discors, with place of attachment of P. pecliculus. 

261. Patella discors, Phil. 

Abbild. und Besch. Conch, pi. 2, f. 6. — Rve. Conch. Ic. sp. 78, 

pi. 29, f. 78, a, h. 

The peculiar characteristic of this species, viz. the crumpling 
near the umbo, is very seldom seen without careful cleaning, 
as the shell is almost always thickly coated with vegetable 
corallinous deposits, algae, &c. The surface is extremely finely 
ribbed throughout, but at a little distance fi-om the black apex 
the shell is gathered into irregular undulations, about 15 (more 
or less) which soon disappear, and leave the shell henceforth of 
a regular growth. It goes through all tlie changes common to 
limpets, being sometimes high, sometimes depressed ; some- 
times suborbicular, generally oval. The margin is extremely 
finely crenated, and is generally more or less dotted with black. 
The prevailing colour is a greenish white, with more or less 



2(>2 MAZATLAIf rNITALTES 

distinct radiating black lines. Sometimes tlie internal siirface 
is beautifully mottled witli i)iirple or brown. Tlie animal 
mark is by no means constant in shape ; but, when well defined, 
shews the body gathered pretty regularly into points with 
curves between. The smallest specimen is about '25 in length : 
the largest measures long. 2 '15, lat. 1'7, alt. '72 
.H??5.— Mazatlan, Lieut. Sliwley.—'^. W. Mexico, P. P. C— 

Mazatlan verj- common ; L'lmol ^' Havre Coll. 

Tablet 923 contains 4 sp. A-arious ages. — 924, 4 specimens 
white. — 925, 5 do. greenish tinge. — 926, 4 do. coloured within. — 
927, 4 do. tortoisesholl.— 928, 8 sp. yellowish tinge.— 929, 4 do. 
very faint appearance of marginal dots.— 930, 7 do. a shade 
more developed. — 931, 8 sp. black rays coated over. — 932, 7 sp. 
black dots distinct. — 933, 7 do. more distinct. — 934, 7 do. well 
developed. — 935, 5 sp. faint black dotted margin. — 936, 5 do. 
distinct black margin. — 937, 6 sp. with brown tortoiseshell 
markings. — 938, 5 do. purplish tinge. — 939, 4 do. black and 
brown. — 940, 3 sp. body mark distinct. — 941, 3 sp. margin 
abnormally indented. — 942, 5 sp. irregular internal growth. — 
943, 1 do. T\ith large Balanus, Lithophagus, &c. 

Genus NACELLA, Schum. 
Patella, pars, and. 

262. Nacella, , sj). ind. 

Tablet 944 contains a solitary specimen of a JS^acella, of the 
shape and size of Ancylus fluviatilis, with the apex spirally 
recurved, and of a dark hornj' coloiu-. It is not perfect enough 
for description. 
Kah. — Mazatlan ; off Chama, 1 sp. ; Upool Col. 

Family ACM^ID.E. 

Genus ACM^A, Esch. 

Esch.<tcholtz Zool. Ail. ed. Rathke, 1833, p. 16, (di^gnosi copiosa.) 

— Forbes Sf Hani. Br. Moll. vol. ii. p. 434. — Woodw. Man. 

Moll. p. loo.— Phil. Handh. Conch, p. 199. (Non Acme, 

Hartm. 1821.) 
Lottia. G-raii in Phil. Trans. 1833. and in Sow. Gen. 1833. 
Patelloida, Quoi/ Sf Gaim. 1834, Toy. Astr. vol. iii. p. 349. 
Tectura, Audouin ^- Milne Edw. Ann. Sc. JS'at. 1830, vol. xxi. 

p. 226, (Gray: p. 325, Phil.J—H. ^ A. Ad. Gen. vol. i. p. 458. 



MAZATLAN UNIVALVES 203 

263. ACM^A MESOLEUCA, Mke* 

A. t. "Acmceis 2iatin<s et testudinali" simili ; tenui, subdia.' 
pJianci, rarius solidiore : extus, apicem versus lcBvi,postea lirtdis 
tenuihiis suhdistant'tbus irreciidaribus ornatii, sape mimdissime 
granulatis, inierdum crassiofi'bus, appj'ophquantibus ; fusco- 
oUvaced, interdum fusca, rarius nigro-fuscA ; varie tessellatd, 
lineatd sen maculata, interdum unicolore : intus, margine fusco 
et albido, sen nigro-fusco ; medio x>Tus mimisve viridi, seu alhido- 
viridi, interdum Jlavescente seu flavido-viridi ; spathuld ftiscd. 
seli fusco-olivaced, capite stibtriangulari, corpore interdum ir- 
regulariter pectinato. 

Mice, in Zeit.f. Mai. 1S51, p. 38, no. 135, (diagn. supra auct.) 
? + A. mutabilis, pars, 3Ike. loc. cit. p. 37, no. 133. 
= Patella diaphana, Rve. Conch. Ic. pi. 24, sp. 61, f. 61, a, b, 1854. 
? = Patella diapliana, Nutt. in Jai/'s Cat. no. 2813, (sine diagn.) 
? = Lottia patina? C. B. Ad. Pan. Shells, p. 241, no. 367 (non 

A. patina, Esch.) 
Pars ? = Patella (Acnisea?) personoides, Midd.- Mai. Eos. pt. ii. 

p. 37, no. 10, pi. 1, f. 2, 1819 :— ( = A. ancj-loides, 3£id, olim, 

non Propilidium ancj'loide, Forbes.) 
Var. ? = Patella (Acmsea?) feruginosa, Mid. Bui. Acad. St. Pet. 

vol. vi. no. 20 -.—Mai. Ros. pt. ii. p. 38, no. 11, pi. 1, f. 1. 
= Lottia pintadina (pars) Gould Exp. Shells, 1846, p. 9. 
Comp. Patella floccata, Rve. Conch. Ic. 

„ „ vespertina, Rve. loc. cit. pi. 26, f. 67, a, b. 

„ ,, Cumlngii, Rve. loc. cit. pi. 16, f. 37, a, b. 

Var. = Patella striata, Rve. loc. 'cit. pi. 33, f. 99, a,b.: (non 

PateUoida striata. Quoy ^' Gaim. Voy. Astr. Moll. pi. 71, 

f. 8—11 -.—Rve. Conch. Ic. sp. 58.) 
= Acm8ea AntUlarum, P. P. C. Cat. prim.: non Sow. ( = A. 

testudinalis, teste Gould Inv. Mass.) 
= Acmaja patina, P. P. C. Cat.prov. {non Esch.) 

* It is difficnlt to say which name should be retained for this species. It is 
figured as P. diaphana by Uceve, the name having been received by Mr. Cuming 
from Jay as of >"uttall. Mr. Kuttall's own specimens however of "the green lim- 
pet are from Mazatlan, nor does he remember taking them in Calilbruia ; and 
ft is probable that he gave the name to the parallel variety of A. patina, to which 
the green shells brought by IJiuds, Kellett, kc. were aifiliated. At any rate ir 
can only claim priority from the date of its appearance in Reeve. Gould's name 
would liave been retained, but that unfortunately his type specimens consist of 
P. verrioulata, leucophrea and seahra, iZce., ^\-ith A. mesoleuca aud lascicularis, 
MTcc. If one or both of Middendorff's species should prove identical with the 
Mazatlan species, the name A. personoides should be retained : but even that 
author's very copious descriptions do not allow us to speak with conlidence, 
without a comparison of types. Under these circumstances, as Menke 3 name, 
though given later, certaiiily represents the Mazatlan si)eeies in its usual state, 
it is thought best to retain ic. 



204 ilAZATLAK TJXIVALVES 

Tliis species, and its more temperate analogue, A. patina, go 
through the same varieties of form and pattern ; some of which 
are so divergent that it is not to be wondered at that they 
have been described as distinct ; and others are so marvelously 
alike that they can scarcely be separated from each other by 
figure or description. The habit however of the two species is 
sufficiently distinct ; and those who have examined large 
multitudes of specimens will have little difficulty in separating 
them. The simplest guide is the prevailing green and brown 
colour of this species, and the prevailing white and black 
of the other. The character of the ribs, which Ls mainly relied 
upon by Middendorff, appears subject to great variation. 

Shell extremely variable in colour and markings, but gene- 
rally rather broad and flat, with the apex somewhat inclined 
anteriorly, especially in the young shell. Outside with the 
apex and sometimes a considerable portion of the shell nearly 
smooth ; generally with extremely fine ribs, sometimes sharp, 
sometimes rounded, generally sHghtly granulose ; sometimes 
with broad strong ribs ; sometimes nearly smooth with radiat- 
ing lines of granules. Sometimes intercalary ribs are found, 
much larger than the rest ; sometimes difterent plans of sculp- 
ture are seen on the same shell. The colour outside is generally 
olive or brownish green ; sometimes without markings, gener- 
ally with white lines either radiating or broken up ; often with 
white patches tessellating with the brown ; or changing from 
one pattern to another. Inside the shell is generally whitish 
about the middle, (whence the name,) with more or less of a 
bluish green tinge, sometimes dark green, sometimes brownish, 
sometimes with an element of ochre yellow more or less mot- 
tled, (? P. aeruginosa, Mid.) There is almost always a large dark 
spot at the body mark, of a brownish olive green, in which 
sometimes the brown, sometimes the dark green predominates. 
The body stain is irregularly and shghtly gathered mto points ; 
the head mark is generally shewn by a stain shaped like a 
sector, bounded by two radii from the apex, about 70° apart. 
The margin is generally broad, occasionally very narrow, 
bounded inside by a gi-eeuish line ; ordinarily tessellated with 
brown and white, sometimes with green or yeUow ; not un- 
frequently with very slight markings of white, or none at all ; 
in which case the colour is either dark greenish brown, (P. 
striata, Bvc. sp. 69, non Quo//, sp. 58). or with intermediate 
stages to very light greenish white. That all the shells hero 
classed together belong to the same species, I have not the 



MAZATLAN TJNIVAI/VES 2(S 

slightest doubt, liaring carefully examined about 11,000 speci- 
mens, from wliicli those here enumerated were selected by a 
carefully repeated process of reduction and comparison. No 
very young shells were found ; the yoimgest measuring "5 in. 
in length ; the largest, lorifj. 1'56, lat. 1"33, alt. '39. 
ilaJ. — Mazatlan ; in extreme profusion; L'pool Sf Savre 
Co/^.— Central America, Cuminq, Hinds, Ze?Za«.—? Panama; 
on and under stones at neap tide low water mark, rare ; 
G. B. Adams. — (A. seruginosa. Mid. non Rve. Conch. Ic. pi. 16, 
sp. 38) Bodejas, Wosnessenslci. — (A. striata, Rve.) Gallapagos, 
Cuming. — (A. ijersonoides) Kenai Bay, Wosnessenslci. 
Tablet 945 contains 28 specimens in the normal state, outside 
striped, with a prevailing greenish tinge, and regularly tessel- 
lated margin. — 946, 26 sp. do. outside tessellated. — 947, 27 sp. 
do. prevailing brownish tinge ; more often worn outside. — 
948, 5 sp. the same, tessellated. — 949, 12 sp. yellowish ground ; 
broad streaks of brown. — 950, 6 sp. do. narrow streaks. — 951, 
6 sp. do. scarcely rayed. — 952, 12 sp. do. tessellated. — 953, 4 do. 
greenish tinge. — 954, 6 sp. border with broad patches of dark, 
narrow .of light, green inside ; yellow ground. — 955, 6 sp. do. 
light ground. — 956, 6 sp. do. tessellated. — 957, 6 sp. brownish. — 
958, 8 sp. broad dark margin, interrupted by narrow light 
rays ; brownish cast. — 959, 10 sp. green cast. — 960, 4 sp. hght 
border ; brown, finely rayed with white. — 961, 9 sp. do. faintly 
mottled. — 962, 2 sp. do. with pm'plish tinge. — 963, 8 sp. do. 
with narrow brown dotted edge. — 964, 9 sp. do. green tinge, 
mottled with brown. — 965, 4 sp. do. green margin, scarcely 
tipped with brown. — 966, 4 sp. do. very light. — 967, 1 sp. do. 
nearly white. — 968, 4 sp. do. with dark brown edge. — 969, 8 sp. 
margin nearly \miform ; dark, witlx a few white rays. — 970, 
8 sp. do. scarcely mottled with white. — 971, 12 sp. do. lighter 
tint. — 972, 9 sp. margin unifoi'm, ( = P. striata, jun. J?i'e. not 
Quoy,) dark green. — 973, 11 sp. do. intermediate. — 974, 9 sp. 
brown. — 975, 8 sp. of distorted growth ; of M'bichone has made 
a series of raised laminte, another a fresh margin greatly con- 
tracted. — 976, 5 sp. shewing the exterior ; tessellated. — 677, 
7 sp. do. abounding in white. — 978, 3 sp. do. striped — 979, 4 sp. 
do. pattern changing. — 980, 4 do. dark green var. — In all 301 
specimens, of which no two are exactly alike. 

, 264. Acm.i;a fasciculaeis, Illce. 
Zeit.f. Mai. 1851, p. 38, no. 134. 
+ Acmgea mutabilis (para quidem jun.), Zcit. f. Mai. 1851, 

p. 37, no. 133. 
May 1856. t 



206 MAZATLAN TXITAIVES 

= Patella opea, teste Rve. : nou Nutt., in Itve. Conch. Ic. 

sp. 79, pi. 29, f. 79, a, b. (Sandwicli Isl.) 
Var. = P. discors, jiin. P. P. C. Cat. prim. 
Tlie following W. Indian species in the Br. Mns. are closely 

analogous : Lottia lineata, Tranquebarica, and pulcherrima, 

(G-uilding.) 

The exquisite beauty of this "most lovely species" (as 
Menke deservedly calls it), both for the shading of the colours 
and the delicacy of the penciling, cannot be described. The 
prevaUing tints are a reddish brown outside, more or less 
mottled or striped with white ; inside a prevading white, more 
or less penciled or fretted with brown, and a border, sometimes 
white with a tessellated penciling of brown ; sometimes a 
delicate fawn shading into a pinkish or slightly greenish tinge, 
with or without pencding. The body mark is of a dark lus- 
trous brown, or very light with a greenish tinge, or nearly 
absent. It is large for the size of the sheU, more or less 
removed from the margin. The young shells of A. mutabilis, 
Mke. are a variety of this species ; which I uufortxmately 
distributed at first as the young of P. discors, with which it 
has really no connection. The colourless and worn shells of 
A. mesoleuca and A. fascicularis are verj- like each other ; but 
as their general habits are very distinct, it is necessary to keep 
them apart. In shape, A. fascicularis is much longer, and 
generally considerably smaller. The standard colour of A. 
mesoleuca is green, of A. fascicularis red. In A. mesoleuca 
the markings are laid on with stripes and patches, in A. fasci- 
cularis with very fine pencilings. In the latter, the outhne of 
the body mark is much more regularly gathered up into points 
with concave margins between, the points often making regular 
lines radiating from the centre. The surface of A. mesoleuca 
is covei'ed with granulose ribs with smooth interstices and a 
very thin smooth epidermis ; that of A. fascicularis is very 
much more finely marked, shewing under the glass smooth 
ribs with the interstices extremely finely cancellated with 
very close slightly rugose concentric stria?, covered with an 
extremely thin rather velvety epidermis. The siu-facc of A. 
fascicularis is much more generally abraded ; and as the yoimg 
shells were not uncommon in the Spondylus and Chama 
washings, while not one was found of A. mesoleuca, it is pre- 
sumed that their station is diflerent. The apex is sometimes 
brown, sometimes white ; and in the smallest specimen, "035 
by '025, shews no trace of being spirally recurved. The young 



MAZATLAX nflTALVES 



207 



shells are kno-wn by their finely cancellated texture and deli- 
cate reddish, penciling ; and generally, by a white spot proceed- 
ing from the apex posteriorly bounded by red lines. In all 
stages it is thin, and very glossy within. The largest specimen 
measures long. 1'34, lat. I'Ol, alt. '33. 

Hah. — Mazatlan, Menke. — Do. ; not imcommon ; Upool Col. — 
San Diego ; Lieut. Green. 

Tablet 981 contains 12 specimens, extremely young, whitish. — 
982, 8 sp. do. reddish. — 983, 4 sp. do. much compressed at the 
sides ; Ijut, as they agree in colour and markings, they are 
probably only a variety. — 984, 5 sp. light margin ; scarcely 
touched with penciling. — 985, 5 sp. do. very slight posterior 
pencilings. — 986, 5 sp. do. margin fawn coloured. — 987, 5 sp. do. 
greenish tinge. — 988, 4 do. purplish brown. — 989, '5 sp. pencil- 
ings more distinct. — 990, 6 sp. with faint dots all round. — 
991, 8 sp. do. darker margin. — 992, 8 sp. do. still darker. — 
993, 4 sp. do. very narrow margin. — 994, 3 sp. penciling regular ; 
shght and shaded. — 995, 4 sp. do. white border, penciling in 
single rays. — 996, 8 sp. do. penciling fretted, rays distinct.— 
997, 7 sp. do. margin coloui'ed. — 998, 7 sp. penciling interlaced, 
reddish margin. — 999, 7 sp. do. margin dark with penciling. — 
1000, 9 sp. do.margin very dark, interior white. — 1001, 5 sp. do. 
penciling visible within. — 1002, 3 sp. distorted growth. — 1003, 
6 sp. shewing exterior, rayed. — 1004, 4 do. very slightly. — 1005, 
3 do. uniform red.— 1<X)6, 1 do. with light ring. — In all 146 
specimens, of which no two are exactlj- aUke. 

265. AciiXA PATINA, Esch. 

EscJisclioltz Zool. AH. ed. SatMe, 1831, p. 19, pi. 24, f. 7, 8.— 

Mid. Bid. Ac. Si. Pet. vol. vi. no. 20 -.—Sib. Reise, p. 187, 

pi. 16, f. 1 a-d, 2 a-c, 3. 
+ A. scutum, Esch. loc. cit. p. 19, pi. 23, f. 1—3; teste Mid. 

loc. cit. et Phil, in Zeit.f. Mai. 18i0, p. 107.— ?UOrh. Voy. 

Am. Mer. p. 479 (excl. fig.) 
= Patella manimillata, Nutt. in Jai/'s Cat. no. 2839: — Eve. 

Conch. Ic. 1)1. 42, f. IW, a, h. 
+ Patella tessellata, Natt. in Jays Cat. no. 2885. 
+ Jun. Patella fenestrata, Natt. in Jay's Cat. no. 2815. : — Eve. 

Conch. Ic. pi. 38, f. 121, a, h. 
+ Patella verricidata. Eve. Conch. Ic. pi. 31, f. 87, a, h. 
+ Patella cinis, Eve. Conch. Ic. pi. 24, f. 60, a, b, c. 



208 MAZATLAN UNIVALVES 

? + Patella Nuttalliana, Rve. Conch. Ic. pi. 30, f. 81, a, h. 
? + PateUa Cumingii, Rve. Conch. Ic. pi. 16, f. 37, a, 6.— (Val- 
paraiso, Cuming.) 
? + Patella diapliana, Nutt. non Rve. (v. supra, p. 203.) 
=Lottia pintadina, (pars,) Gotild, loc. cit. in p. 203. 
Comp. Patella clypeater, Rve. (as of Less. Voy. Coq. p. 419) 
Conch. Ic, pi. 16, f. 37, a, b, (Valparaiso, Cuming.) 
I have the authority of Mr. Nuttall, after a careful collation 
of his specimens and those of Dr. Gould, for placing together 
his species above quoted. The ordinary form of the shell 
greatly resembles A. mesoleuca, but Avithout the green tinge. 
The pattern, which distinguishes many of the above species, 
often changes in the same shell. Whether the shells of N. 
and S. America are the same, is not yet decided. The extreme 
form is a large solid white shell, with a broad black rim. To 
this belong the only two specimens found in the Mazatlan 
collection. Mr. Eeeve, who most obligingly named the Maz- 
atlan limpets according to his monograph, affiliated these, and 
some of the dark -margined specimens of A. mesoleiica as their 
young, to P. striata, Quoi/ Sf Gaim. Their sijecies is different ; 
but the yoimg are most probably his own P. striata, sp. 99, from 
the Gallapagos. The A. scutum of Esch. is quite different 
from the large flat shell with a rich metallic lustre, which often 
goes by that name in collections ; this occurred in abundance 
at S. W. Mexico, P. P. C, and is from Monterey, Mus. 
Cum. — The largest Mazatlan specimen measures long. 1'5, 
lat. 1-23, alt. -57. 

Ba&.— Sitcha, Eschscholtz, Wosnessenslci. — Kenai Bay, do. — 
Aleutian Is., Unalashka, Kastaljshi. — Tugur Ba.v, Schantar 
Is., Midclendorff. — California, ])assim, NutfuU. — Monterey, 
San Diego, Lieut. Green. — Mazatlan ; 2 fresh sp. ; L'pool 
Col.—(?) Chili, Bolivia, Peru, D'Orhigny. 
Tablet 1007 contains the most characteristic specimen. 



266. ACM^A rEESONA, Esch. 

Esch. Zool. Atl. p. 20, pi. 21, f. 1, 2.— Mid. Mai. Bos. pt. ii. 

p. 36, pi. 1, f. 3. 
+ Juu. = A. radiata, Esch. loc. cit.. p. 20, no. 8, (teste Mid.*) 
+ A. ancylus, Esch. loc. cit. p. 20, no. 10, pi. 21, f. 4 bis, 6. (do.) 

* Philippi however (loc. cit. supra) regards A. radiata and A. aucylua as 
forming a different species not frona S. America, but liom Chili. 



MAZATLAN TTNIVALVES 200 

-A. scutum D'Orb. loe. cit. pi. 64, f. 8—10, escl. diagn. (teste 

Mid.) 
? = Lottia punctata, Gm?/ ; (uon Quoy Sf Oaim.) teste Mid. 
= P. Oregona, Nutt. in Jays Cat. no. 2853: — Rve. Conch. la. 

pi. 36, f. 112, a, b. 
+ P.umbonata, Nutt. loc. cit. no. 2887 -.—Rve. loc. cit. pi, 35, 

f. 107, ah. 
+ P. pilQata, Nutt. loc. cit. no. 2861. 

Tbds species is known by its comparatively small size, cc«n- 
pressed sides, and recurved apex. The front part is sometimes 
covered with stout, rounded ribs, sometimes with a very few 
fine and separate ones, and sometimes nearly smooth. It is 
either uniform in tint, or is minutely spotted outside ; inside 
white and blackish brown. The solitary Mazatlan specimen 
has broad, rounded ribs, and a somewhat shagreened surface ; 
and measures long. "96, lat. "8, alt. *42. 

JTai.— Sitcha, Eschscholtz. — Mouth of Columbia Eiver, Nut- 
tall. — Sta Barbara, Col. Jeioett. — San Diego, Lieut. G~reen. — 
Mazatlan ; 1 fresh sp. ; L'pool Col. 
Tablet 1008 contaias the specimen. 



267. ACMJEA SCABEA, Nutt. 

Jays Cat. no. 2907.— i?i'e. Conch. Ic. sp. 119, pi. 37, f. 119, a, h. 
Non Patella (Lottia) seabra Gould Exp. Shells, p. 10 : — 

= Patella spectrum, Nutt. in Jays Cut. no. 2877 -.—Rve. loc. 

cit. pi. 29, f. 76, a, h. 

Although the name of Gould was published with description 
before that of Nuttall, yet I have presumed upon the known 
courtesy of Dr. Gould, in order to avoid re-naming a species 
which has been widely distributed in collections, and which 
(as well as Dr. Gould's A. seabra, under the name of P. spec- 
trum) has been figured in the Couch. Ic. This shell occurred un- 
named in Dr. Gould's collections. It frequents the temperate 
portion of the coast, and is easily recognized by its light flesh 
colour, and tubercular rasp-like surface. Long. 1"06, lat. "9, 
alt. '4. 

Sr/S.— California, iV«//«/^.— Monterey and Sta Barbara, Col. 
Jetrei'^.- Mazatlan ; 1 sp. only ; L'pool Col.—S. W. Mexico ; 
1 sp. P. P. C. 
Tablet 1009 contaias the specimen. 



210 MAZATLAN UNIVALVES 

268. AcMiEA MiTELLA, MenJce. 

Zcif.f. 3Ial. 1847, p. 187, no. 43. 

= Pateila navicula, Bvc. Conch. Ic. sp. 130, pi. -U), f. 130, a. b. 

This shell having been first named from a single worn speci- 
men, the minnte details of Menke arc not generally applicable. 
The description in the Conch. Ic. applies to a larger number, 
but not to the whole. Shell small, strong, conical, almost 
exactly resembling a common Barbadoes species (? = P. leuco- 
pleura, JB. M. Cat. Sarjr. Cah. Moll. p. 34, no. 404) ; outside 
either very finely or coarsely ribbed, with or without granules, 
generally eroded or encrusted ; inside white, blackish brown, 
tortoisesheU or light chesnut, often -with a greenish tinge ; 
margin generally with a row of black dots, more or less con- 
spicuously connected with the apex (especially in yoimg shells), 
sometimes coalescing into a black rim, rarely wholly absent. 
Margin sometimes finely creuulated by the projecting ribs, 
sometimes almost entire. Animal mark irregularly and slightly 
gathered up into points. It either excavates a hoUow for itself 
on othQr shells, or keeps its ground clear while the coralline 
grows up round it. Its small size and shape are not the 
result of the accidents of its position,* as it is generally found 
where it has plenty of room to grow larger if it chooses. 

The smallest specimen measvu'es long. "05, lat. "03, alt. "015. 

Aflat „ „ „ -48, „ -35, „ -17. 

A conical „ „ „ -51, „ '39, „ •34. 

Hah. — Mazatlan, Lieut. Shqyley, Mus. Cum. : — do. Melchers, 

Menke : — do, ; not uncommon ; L'pool Col. 

Tablet 1010 contains 5 specimens very young. — 1011, 17 
young shells, each var\-ing in coloiir, &c. — 1012, 30 specimens, 
of which no two are coloured exactl.y alike. — 1013, 4 specimens 
shewing external variations. — 1014, a specimen in situ on 
Fissurclla ; also Patella discors with attachment marks. — 1015, 
a gigantic specimen, if of this species as is probable, measm'ing 
long. -93, lat. '71, alt. -41. 

Genus SCUTELLmA, Gray. 

Scutellma, Proc. Zool. Soc. 1847, p. 168, no. 405. 
Scutella, pars, Brod. Froc. Zool. Soc. 1834, p. 47 : non Lam. 
Patella, pars, auct. 

* Dr. Gray, when first examining this collection, expressed the opinion that 
P. Mexicana, P. discors, A. mesoleuca, A. lascicularis and A, mitella, might be 
varieties of the same species, according to station, food, &c. 



MAZATIAN UNIVALVES 211 

?Pars = Pilidium, Forbes SfSanl.=3o\\Aa, Phil. Sandh. Conch. 
p. 200 :=Iotliia, Grau in Mrs. Grays Fig. Moll. An. p. 93 : 
H. Sf A. Ad. Gen. vol. i. p. 461 : uon Forbes, Athen. 1849, 
{=Lottia, err. tj-p.) teste Woodw. 

Tliis genus is a part of the Sciitella of Brod. (tlie remainder 
constituting the gcuus Broderipia, Grai/, of the family Stoma- 
tellina?,) of which the name was altered to Scutellina by Dr. 
Gray in conseqiience of its preoccupation by Lam. for a genus 
of Echinoderms. 



269. ScCJTELIilNA NAVICELLOIDES, n. S. 

S. t. ohlongtt, lateribus subplanatis, valde incBquilaterali ; 
apice terminali, sed a margine remoto ; tenui, subdiaphana, 
albidd, epidermide tenuissimd cinered indutd ; liris exilliniis 
radiantibm et concentricis, subaqualibus, creberrimis, confertim 
decussatd, ad inter sectiones suhnodosis ; interstitiis quadratis; 
margine a liris radiantibus vix crenulato ; columella (ut in 
"Navicelld") planatd, arcuatd. 

One specimen only of this beautiful and very distinct species 
was found by ]\Ir. Darbishire : the apex was imfortunately 
broken, in detaching the shell from extraneous matter, but its 
place is nearly determined by the sculpture. The margin is 
concave ; the shell resting on its anterior and posterior ex- 
tremities. io«(/. '22, lal. "14, alt. '06. 
ZTaS.— INIazatlan ; 1 fresh sp. from burrow of Lithodomus, in 

Spondylus calcifer ; Upool Col. 

Tablet 1016 contams the specimen, presented by R. D. Dar- 
bishire, Esq. 

Family GADINIAD^. 

This family was placed among the Pulmobranchiata, next to 
Siphonariada^, when the animal was only known bj^ Adanson's 
notice, Gray, 1847 : in the same company, between Caecimi 
and Acma?a, by Philippi, 1853 : next the Patellida?, after 
Philipjii had published a description of the animal, by Gray, 
1850, and M. Sf A. Adams, 1854. The animal is gill-bearing, 
while that of Siphonaria is pvdmouated. The shell has no 
interruption in the musevdar scar for the slit, which is at the 
left of the head, and generally very small. 



212 MAZATLAN rSTIVALVES 

Genf9 GADmiA, Gray. 

Phil. Mag. Sf Journ. 1824, p. 63: — PA^. Kandh. Conch. 

p. 199— S". 8f A. Ad. Gen. vol. i. p. 463. 
Mouretia, Sow. Proc. Zool. Soc. 1835, p. 6 : — Zool. Beech. Voy. 

p. 147. 
Pileopsis and Patella, sp. auct. 



270. GrADlNIA PENTEGONIOSTOMA, SoiO. 

G. t.plus minusve conicd, sere valde depressd, albd; subcirculari, 
sea irregulariter varie angulatd ; cqnce subcentrali, in aduUd 
detrito, injuniorespirali, anfnictihus planorhiformihus, adver- 
sum cervicem laferaliter affixo ; costis 2^lurimis radimitihus, 
angustis, rotundatis, valde extantihus, intersfitiis suheequantibus ; 
margine costis productis, cavatis, subdAaphanis ; canali minima, 
ad marginem haud extante ; cicatrice musculan dextrorsum 
integro, sinistrorsiom irregulariter lobato. Animal cavitatem 
corroderde. 

Siplionaria pentegoniostoma, Soto. ? ubi. 

Having met with, no description of tliis shell, the name of 
•wiuch is likely to mislead, I have drawn out a diagnosis from 
a comparison of several hundred specimens. Most of the shells 
are very irregular in growth, apparently crowding each other 
and forcing their bodies into angular shapes : but the normal 
condition appears to be nearly round, with semi-transparent, 
hollowed, projecting ribs. The muscular scar, on the opposite 
side from the slit, is irregularly divided into lobes. The mus- 
cle of attachment appears very strong, the shell being generally 
broken in removal ; and on the place of adhesion (which is 
eaten away) is generally seen a black circular ring. No very 
young specimens were found, to compare with those of Siphon- 
aria : but on the smallest, '23 in length, is just discernible a 
small planorbiform apex, tm-ned to one side, away from the 
head ; in this respect agreeing with Siphonana and differing 
from Patella. The ribs are of nearly equal size, there being 
no large one to receive the canal, as in Siphouaria. The shell 
often begins very conical, and suddenly becomes flat. A 
regularly grown up sp. measures long. '68, lat. '63, alt. '18. 

The largest sp. „ „ -98, „ -88, „ '43. 

A flattened sp. „ „ "67, „ "53, „ "IG. 



MAZATLAN TJNIVALTES 213 

^a6.— Mazatlan ; gregarious, often adhering to each other, not 

common ; Uiwol Col. 

Tablet 1017 contains 3 sp. finely grown.— 1018, 3 do. usual 
state.— 1019, 3 do. irregularly grown.— 1020, 6 sp. ; one with 
5 corners, another with 4, another with 3, another with 2, 
another with 1, the other circular.- 1021, 2 sp. very deformed 
growth.— 1022, 2 do., one with double margin, the other ex- 
tremely depressed.— 1023, 1 sp. with dead Balani, enclosing a 
Crustacean. 

Family FISSUEELLID^. 
Genus FISSUEELLA, Brug. 

The Mazatlan Fissurellse naturally divide themselves into 
two sections ; the first with the surface irregtdar, and the 
margin not crenulated except by the projecting ri.bs ; the 
second with the surface cancellated, the margin crenulated, 
the apes in the young shell prominent and recurved, the 
callus frequently tnmcated, sometimes laminated. In the first, 
the Eimuloid stage must be of very short duration, as extremely 
young shells were found, of the same form as the adult : in the 
second, this stage continues for a comparatively long period, 
as may be observed in the English species, as well as in the 
specimens here recorded. To the latter group H. & A. Adams 
(Gen. i. 447) have unfortiinately given the name of Lucapina, 
as of Gray. The animal however of Gray's typical species, L. 
crenulata (Fig. Moll. An. p. 92, no. 159), is described by 
Nuttall as like that of Parmaphorus, extremely large, and 
completely enveloping the shell. — The shape and markings, 
which in most species are tolerably constant, are in others very 
variable : even the form of the aperture and callus is in some 
instances remarkably changeable. 

Section A. Margin interru2)tcd hy ribs. 

271. FlSSUEELLft. TIEESCENS, SoW. 

Proc. Zool. Soc. 1834, p. l2o.—31iill. Syn. Nov. Test. Tiv. 
p. 154.— /Soio. Conch. III. sp. 31, f. 37 (quasi F. coarctata, 
King.)—Rve. Conch. Ic. pi. 4, f. 12, sp. li.—Mke. Zeit. f. 
Mai. 1851, p. 36, no. 130.— C. B. Ad. Pan. Shells, p. 238, 
no. 3Q1.—S. & A, Ad. Gen. i. 446. 



1-7, „ 


122, , 


•65 


1-95, „ 


1-48, , 


•62 


1-75, „ 


1-49, , 


•67. 


1-75, „ 


1-34, , 


•77 


•8, ,. 


•56, , 


•2, 



314 MAZATLAN rXIVALYES 

This species scarcely differs from F. nigropunctata, Sok'. 
except in the entii'e absence of black dots round tlie margin. 
Shell with veiy numerous fine ribs, with still finer ones between, 
sometimes slightly nodulous. Outline more or less oval, more 
or less conic ; growth regular. Hole large, subcentral, deeply 
chiseled, oval, constricted in the middle externally, where it is 
bilobed. Colour olive green, often stained with red when 
polished. Surface frequently eroded. Interior from pale to 
dark green ; margin crenated by the ribs ; callus rather thick, 
radiately corrugated, not bounded by a dark line. Muscular 
impression distinct. The young shells (which were very rare) 
are shaped like the adult, with the hole even larger in propor- 
tion. The largest sp. measures long. 2'2, lat.1'66, alt. '8. 
An elongated sp. „ 

A flattened sp. ,, 

A rounded sp. „ 

A conical sp. „ 

The smallest sp. ,, 

with a hole -13 by -OS.—Div. 1000—120^. 

Sal. — Panama ; in exposed situations at low water ; Cuming. — 
Do. ; common, on a ledge of rather smooth rocks, between 
half tide and low water mark, in a place somewhat exposed 
to the sea; C. B. Adams. Mazatlan ; very common; 
L'pool Col. 

Tablet 1021 contains 10 sp., various ages, normal state, — 
1025, 4 do., elongated form. — 1026, 4 do. flattened form. — 
1027, 3 do. rounded form.— 1028, 2 do. conical.— 1029, 2 do. ribs 
strong. — 1030, 2 do. ribs faint. 

Tablet 1031 contains 2 sp. surface cleaned, shewing red tint 
beneath. — 1032, 5 sp. shewing shades of colour within. — 1033, 
2 sp. diseased from worms, &c. — 1034, 1 s\}. hole irregular 
through accidental breakage. 

Tablet 1035 contains a remarkable monstrosity with 2 holes. 
The first is in all respects normal. The second is adjacent 
anteriorly, perfectly round, with a thick callus within, united 
to that of the normal hole posteriorly, anteriorly rather 
pointed.* 

• A similar monstrosity appears in a specimen of F. omata in Mr. Nuttall's 
collection. The shell is abnorraally conical, with the hole nearly round instead 
of ohlonp;, bilobed. The second hole commences 3-5ths down towards the anterior 
margin, is yery minute, and finds its exit close to the other at the apex. It is 
surrounded bv a thick callus. A still more remarkable monstrosity, without a 
hole at aD, exists in D'Orbigny's Col. v. li. 31. Cat. IXOrh. Moll. p. 51, no. 435. 



MAZATLAN UNIVALVES 215 

Tablet 1036 contains a sp. witii the hole not constricted in 
tlie middle. 

Tablet 1037 contaias a sp. witli a circidar bole. Nodulous 
ribs strong. Inside white witliin the muscular scar, and at 
the margiu. In other respects like the typical form. It would 
have passed for a distinct species, but for the intermediate 
form q^uoted above ; and closely resembles F. Barbadensis. 

[272. FissuEELLA Baebadensis, Gmel. 

Patella Barbadensis, Gmel. p. 3729, no.' 199 : + P. perforata, 

Gmel. p. 3730, no. 202 : + P. porphyrozonias, Gmel. p. 3730 ; 

Billtv. p. 1061, no. 102 : + P. rosea, Gmel. p. 3730 ; teste 

B. 31. Cat. Cub. Moll. p. 33, no. 400. 
Patella perforata, Dillw. Bescr. Cat. p. 1558, no. 95. 
Fissurella Barbadensis, Lam. An. s. Vert. vol. vii. p. 595, 

no. 9 : et auct. 
Cremides Barbadensis, S. Sf A. Ad. Gen. i. 446. 

One small specimen of this well known West Indian species 
was found, which might have been taken for an extreme variety 
of F. rugosa, were it not for an abundance of the Spiroglyphus, 
and a trace of the red coral, both of which are characteristic of 
the Atlantic ocean, and are entirely absent from the genuine 
Mazatlan shells. It is perfectly fresh, and probably came over 
on a pebble as ballast. 
Hah. — Cuba, Sax/va. — Barbadoes, Lamarck et auct. — Mazatlan; 

1 small specimen, ? imported in ballast ; L'pool Col. 

Tablet 1038 contains the specimen.] 

273. FissuEELLA sraosA, Soto. 

F. t. maxime variante ; x'l^'^u^nque costis plus minusve cEqiiali- 
hus, interdum nodulosis, interdum quihusdam alteras maxime 
supo'antihus ; margine valde in'eyulari, interdum ovali, inter- 
dum elongato, plerumque antlce angulato, a costis plus minusve 
crenato ; apertura liaud centrali ; seu subcirculari, ovatd ; seu 
oblongd, medio constricta; seu bilobatd; seu trilobatd; seu lineari, 
ad extremitates lobatd : callositate plus minusve extante, seu 
concolore, seu lined, purpurea cinctd ; superjicie externa rubra- 
olivaced, seu rubra, seu cinered. ; interna virescente, interdum 
rub ro plus minusve maculatd ; formd plerumque planatd, inter- 
dum. subconicd. 
Conch, m. sp. 66, f. hi.—Bvc. Conch. Icon. pi. 8, f. 56. (Diagn. 

auct.) 



216 MAZATLAJ.' riTIVALYES 

Cremides rugosa, H. Sf A. Ad. Gen. i. 446. 

+ Fissurella clilorotrema, Ilhe. Zeit.f. Mai. 1847, p. 186, no. 40. 

Fissurella liiimilis, Mke. loc. cit. no. 41. 

? + F. yiminea, Mke. Zeit.f. Mai. 1851, p. 36, no. 131 (non Rve.J 

=FissureUayirescens, jun. P. P. C. Cat. Prov. 

It is not to be wonderecl at tliat Meuke did not find any 
figure in tlie Conch. III. answering to Lis sliells ; as the specifs 
was described from not very characteristic specimens of a rare 
and extreme form of this very variable shell. Although placed 
by H. & A. Ad. in a different subgenus from F. virescens, 
some forms run so closely into the young of that species, that 
it was only after repeated examinations of some thousands of 
specimens, and the fortunate discovery of a very few of the 
real F. virescens, .y jo?, that I felt justified in separating them. 
The chief difi'erences are, (1) that F. virescens is of a very 
regular, F. rugosa very irregular habit of growth : — (2) that 
F. rugosa is much smaller, and never has the hole central, 
though the amount of inequality is very variable : — (3) that 
the hole of F. virescens is always much larger in proportion. 
The station also appears different, as F. rugosa is very fre- 
quently entirely covered with algfe, and seldom rubbed : while 
F. virescens is generally rubbed ; and only one (doubtfid) speci- 
men was found with alga?. In the ordinary growth of the shell, 
the ribs are not much more unequal than in F. virescens. The 
most remarkable featui'e in the species is the great variation in 
the shape of the hole ; in this respect resembling F. ornata, 
Nutt. and F. macrotrema, Sow. The extreme forms however 
pass into each other by such insensible gradations, that it is 
scarcely possible to regard them as otherwise than one species. 
The youngest specimen, though only 'OSo in length, with a well 
formed suboval hole, has no spiral vortex ; there is however a 
scar where it may have adhered.* In a larger specimen, '11 in 
length, the shell is formed as in the adidt, light red, with an oval 
hole. The largest specimen measures long. 14o, lat. "97, alt.^Si. 

A broad specimen ,, „ 1'18, „ '87, „ '34. 

A conical specimen „ „ "92, „ '62, „ '3, 

A flat sp. (shape resembling Clypidella) '74, „ '53, „ "11. 

An elongated sp. „ „ ,. 1-03, „ "SG. „ "24. 

Holes, -08 by -06 ; 13 by -Ql. Div. 130"— 160^. 

• If farther investigation should prove that the apex of these species is decidu- 
ona, while in the next section it is persistent until it becomes absorbed in the 
progress of the hole, it will form a remaikable character of separation between 
the groups. 



3IAZATLAN UNIVALVES 217 

^ai.— Gallapagos Is., Camiuy. — Mazatlau ; not uncommon, 

frequently growing on uneven surfaces, and often covered 

witk alga) ; L'pool Col. 

Tablet 1039 contains the two yoangest specimens. 

Tablet 1040 contains 3 sp. smooth growth, hole oval. — 1041, 
3 do. regular form, hole with medial constriction. — 1042, 3 do. 
elongated growth. — 1013. 2 do. hole trilobed. — 1044, 1 do. hole 
elongated, lobed at each end. 

Tablet 1015 contains 3 sp. rough growth, hole roimded oval.— 
104'(5, 3 do. hole elongated oval. — 1047, 3 do. with medial con- 
striction. — 1048, 4 do. hole elongated, obscurely trilobed. — 
1049, 5 do. hole sub-linear, lobed in the middle. 

Tablet 1050 contains 5 sp. ribs varying from fine and equal 
to very coarse and unequal. — 1051, 3 s]). red colour developed 
outside. — 1052, 7 sp. with more or less of red staijis within. — 
1053, 2 sp. dark line round callus weU developed. — 1054, 2 sp. 
elevated gro-s\-th. — 1055, 1 sp. with two large perforations 
(made by PLithophagi.) 

274, FiSSrEELLA nigeocixcta, n. s. 

"F. t. ovali, laid, conicd ; alba, lineis nigris radiantihus 
eleganter pictd ; striis radiantihus tenue ccelatd ; aperturd 
suhcentrali, obscure trilohatd ; inhts alba, margine tenue crenu- 
lato, denticulis nigns ; callositate alhd, lined nigrd cinctd." 

"Differs from the young of F. alba in its greater breadth, 
less compressed growth, finer strije and crenulations ; from F. 
nigropunctata, in the Ijlack line round the callosity ; and from 
both in the form of the hole, which is trilobed, not contracted 
in the middle. Long. '75, lat. '52, alt. "3." 
Proc. Zool. Soc. Dec. 1855. 
Hah. — Mazatlan, Mus. Cuming. — ?Do. ; extremely rare, on 

Spondylus calcifer ; L'pool Col. 

Tablet 1050 contains one of two very young specimens "07 in 
length, which may belong to the above species, described from 
specimens in the Cumingian CoUection. ^Vlthough so small, it 
displays no trace of spiral vertex. Shell white, with black 
stripes. Hole suboval : this may be a character of youth. 

275. FiSSUEELLA , sp. ind. 

SheU elongated, conic, much compressed ; ribbed as in F. 
virescens, &c. ; anterior side shortened ; hole long, narrow, 
trilobed ; colour green within, nigropunctate at the margin ; 
May 1850. v 



218 MAZATLAN UNIVALVES 

callus white, corrugated, not bordered. Differs from F. nigro- 
punctata in the shape of the hole ; from F. virescens in this 
and in the nigropunctation ; from F. alba in both characters, 
in the green colour, and in the still more compressed growth 
as compared with that species ; from F. nigrocincta, in the 
green colour and absence of black ring ; from the conical 
variety of F. rugosa in the regular growth, and nigropuncta- 
tion, which is never seen in that variable species. The outside 
not being in good condition, and the young of some of the 
above species not having been observed, it is not thought 
prudent to name it. Long. '55, lat. 'B6, alt. '2. div.90''hySo''. 
Hub. — Mazatlan ; 1 sp. only ; I! pool Col. 
Tablet 1057 contains the specimen. 

276. FiSSUEELLA ALBA, n. S. 

F. t. ohlongd, compressd, conica, regulari, antice curtiori ; 
alba, rarms nigro radiatd ; liris radiantibus, subaqualibtts, 
interdum Icevioribus, interdum validis, valde nodulosis; apertura 
majore, oblongd, in medio constrictd, parietibiis solidis, s(ppius 
in medio elevatis ; intits albd, seu pallidissime earned, rarissime 
vix vii'idi tinetd, nitente, scepitis anmdo nigro callositatem 
oblongam circumeunte, margine secundwm liras crenulato, in 
testdjimiore scrpe nigropunctatd. 

Jun. ? = F. gemmata, Mhe. Zeit.f. Mai. 1837, p. 186, no. 42. 

This well marked species is easily recognized by its elongated, 
compressed, conical and regular growth. The young shell is 
often rayed outside, and dotted in the inner margin with black : 
else it is of a French white, or very pale flesh colour, glossy 
inside ; rarelj^ with a slight greenish tinge near the callus. 
The ribs are generally rather fine and irregularly tuberculous ; 
sometimes strong and nodvdous ; very rarely slender and 
almost smooth. The black band round the callus is usual, but 
not constant. The F. gemmata of Jf^-e., . described from a 
single smiill shell, is probably a rubbed young specimen of this 
species ; but the diagnosis does not accord with sufficient 
accuracy to adopt his name. The shells are generally more or 
less incrusted with coralline, which often grows in irregular 
longitudinal rays, occasionally meeting over the centre of the 
hole, which thej' thus render bipartite. The aperture is large 
and long; its walls constricted in the middle and at the same 
place elevated on each side. The smallest shell foimd, in 



I 



MAZATIAN UNIVALVES 219 

which the hole preserves the normal characters, measures 

long. '48, lat. Z, alt. "IS. 

The largest sp. (elongated) „ 1*67, „ 1'06, „ "6. 

A normal sp. „ 1'56, „ 1'08, „ '62, 

A conical sp. „ 1'34, „ '96, „ •62. 

Hole of largest sp. "S by " 12. Div. 95" by 105". 
Hah. — Mazatlan ; common ; L'pool Col. 

Tablet 1058 contains 8 sp. different ages, normal state.— 1059, 
3 sp. elongated.— 1060, 3 do. smooth.— 1061, 3 do. elevated, 
nodulous. —1062, 4 sp. shewing interior.— 1063, 3 sp. with singu- 
lar growth of coralline. — 1064, 1 do. smooth, with Acmeea 
mitella in situ.— 1065, 1 do. nodulous, with dried animal of 
adherent limpet. — 2066, 2 sp. hole abnormally produced, 
(div. 85".)— 1067, 3 sp. with Balani, and attachments of hmpets. 
In one (empty), a young Isognomon has taken up its abode. 
Another (spinous) has inserted a fang through the hole of tha 
shell. — 1068, 3 sp. distorted growth. 

Section B. Margin smooth. 

277. FissuEELLA Peruviana, Lam. 

Lam. An. s. Vert. vol. vii. p. 599, no. 11.— B. M. Cat. D'Orb. 

Moll. p. 51, no. 432. 
+ FissureUa subrotuudata. Desk. Enc. Metli. Vers, vol. ii. 

p. 135, no. 11 : — Lam. An. s. Vert, vol vii. p. 602, no. 26. 
Var. = Fissurella affinis. Gray, Proc. Zool. Soc. 1834, p. 125. — 

Soiv. Conch. III. p. 4, no. 35, f. 44. 
Cremides Peruviana, S. Sf A. Ad. Gen. i. 446. 

Only one specimen, and that somewhat worm-eaten, was 
found of this characteristic S. American shell. Shell very 
conic, slightly ribbed, hole nearly round, anterior side pointed, 
inside white, with a sharp, non-crenated, narrow margin, 
shaded with purplish brown. Long.l"^5, lat. 1'12, alt.'GS. 
Hab. — Peru, Humholdt Sf Bonpland.— Is. Mexillones, Lobos; 

Iquiqui and Valparaiso ; Cuming. — Mazatlan ; 1 specimen ; 

L'pool Col. 

Tablet 1069 contains the specimen. 

278. FiSSUEELLA SPONGIOSA, «. S. 

F. t. elongatd, compressd, conicd, antice angustiore, postice 
dilatatd ; superjicie externd quasi i^pongiosd, nee liratd nee 
striata; viridi, juniore lineis, adultd maculis castaneis radi- 



WO MAZATLAN UNIVALVES 

antihus pictd ; apertura elongata, obscure trilobata ; pagind 
interna nitente, cincreo-albida, maculls externis plus minusve 
monsfrantibus, callositate marginem versus rubro-piirpu/reo .- 
cicatrice musculari irregulari, intus ccdlosa, antice punctulata ; 
margine aciito, Jiaiul crenuluto, testa juniore castaneo punctata. 

Only two specimens were found of tMs singular little shell ; 
the younger one of which, though the most highly coloured, 
is diseased withui, and displays neither the lurid colour of 
the fjBcal callus, nor the punctures on the anterior part of 
the general callosity which fills up the space between the 
irregularly jagged muscular scar and the region of the hole. 
It most resembles F. catillus, Bve. The external surface is 
loose and rough. Long. '7, lut. miiice "3, postice "43, «Z^. "24, 
div. 105" by 80°. Hole ' 14 by -04. 
Hah. — Mazatlan ; extreme^ rare ; IJpool Col. 

Tablet 1070 contains the larger spechuen. 



Subgenus GLYPHIS. 

Animal margine palliijimbriata.. marginem testae superantc. 

Testa superficie cancellata, margine crenulato, callositate 
scepe truncatd, interdum laminatd ; testd juniore Mimulcsformi, 
spird in apertura crescente uhsorptd. 
Lucapina, S. Sf A. Ad. Gen. i. 147, (maxima pars) : non Gray. 

279. Glyphis in,t:qualis. Sow. 

Fissurella inrequalis, Soio. Proc. Zool. Soc. 1834, p. 126 : — 

Conch. III. no. 36, f 45.— JJre. Co)icli. 7c.pl. 7, sp. 50. 
Lucapina intcqualis, S. Sf A. Ad. Gen. i. 447. 
+ Fissurella pica, Soic. Proc. Zool. Soc. loc. cit:— Cowc7<. HI. 

no. 37, f. 32, ct var. f. 3S.—Rvc. Conch. Ic. pi. 7, sp. 49.— 

Mke. Zeit.S. Mal. 1847, p. 186, no. 39. 
Lucapina pica, H. Sf A. Ad. Gen. i. 418. 

The extreme forms of this species are very dissimilar : the 
one being very ina^ciuilateral, with a long narrow trilobed slit, 
and sharply trimcalod l)icusi)id callus within : the other sub- 
a'quilateral with a nearly circular hole, and the callus not 
truncated. The specimens with an oval hole are F. pica. Sow. 
and the 8uba;quilatcral form is figured in the Conch. III. as 
F. pica, var. Between the extremes, there is every gradation, 



MAZATLAK UNIVALTES 221 

SO that no point can be fixed on where one begins and the 
other ends. The pi'esent series is earefidly selected from 
several hundred specimens, with a view to shew the gradations 
and extremes of variation. The external surface is more or 
less strongly cancellated, and the margin similarly denticulated. 
Very rarely it approaches the form of G. alta. A young 
specimen "083 in length, displays a flattened spiral vertex as in 
Eimula, with the hole adjacent, well-formed and encroaching 
on the vertex, without channel ; outside suboval, very slightly 
constricted ; inside -with the callus not trimcate. The largest 
specimen measures long.!', lat.'56, alt. '26. 

A broad sp. „ *53, „ '34, „ *15. 

A conical sp. „ '58, „ '4, „ "23. 

An insequilateral sp. measures lo»(/. ant."2A, long. post. '^L 
A subsequilateral sp. „ ,, '23, ,, "29. 

Div. 1000—135°. 
Sab. — Guacomayo & Gallapagos Is. : under stones on the 

shore ; Cuming. — (F. i)ica) St. Elena aud Gallapagos Is. ; 

on dead shells 6—8 fm. ; Cuming. — Var. Monte Christi, 

Cuming. — Mazatlan ; not common ; L'pool Col. 

Tablet 1071 contains the very young' sp. — 1072, 4 sp. normal 
shape, different ages. — 1073, 5 sp. shewing changes of colour 
within. — 1074, 7 sp. shewing change in form from G. insequalis 
to G. pica. — 1075, 4 sp. shewmg change in form of internal 
callus. — 1076, 2 sp. strongly cancellated. — 1077, 3 sp. shewing 
changes from depressed to conical. 



280. Glyphis alta, C. B. Ad. 

FissureUa alta, C. B. Ad. Pan. Shells, pp. 236, 320, no. 355. 
Lucapina alta, H. Sf A. Ad. Gen. i. 447. 

This pretty little species is known by its very conical, 
narrowed shape, and strong cancellating ribs. The smallest 
specimen "01 in length, displays a well ciu'ved Rimuloid apex, 
and a round central hole, without channel ; another smaller 
hole in the spire may be accidental, or it may display the 
relationship of the family to Haliotida). Another specimen, 
though only ' 1 in length, has lost all trace of spire, but presents 
the characteristic suboval, slightly bilobod hole of the species. 
Tlie shell is produced and thick at the vertex : interior callosity 
truncate and slightly indented anteriorly. Lovt/. "49, lat. '32, 
alt. -23. 



222 MAZATIAN UKIVAIVES 

Hab. — Panama, rare, C. B. Adams. — Mazatlan ; extremely- 
rare ; L'pool Col. 

Tablet 1078 contains the two smallest specimens. — 1079, the 
largest specimen. 

Genus EIMULA, Defr. 

Vide A. Ad. Monogr. Rim. in Proc. Zool. Soc. 1851, p. 226 :— 
JI. ^ A. Ad. Gen. vol. i. p. 451. — Non Eimula, Lowe, Proc. 
Zool. Soc. 1854, p. 181. 

This beautiful genus is exactly intermediate between Fissu- 
rella and Emarginula ; representing .permanently the j'oung 
state of Fissurella, and, apparently, in its own young state 
resembling Emarginula. Like other Oolitic forms, it has 
hitherto been found recent onlj' in the Eastern Seas. 

281. EmuLA Mazatla>"ica, n. s. 

P. t. parvd, ohlongd, compressd, conica ; alhida, epidermide 
tenui alho-fuscd indiitd ; apice planatd, angustd ; superficie 
tenue cjxncellatd, cancellis quadratis ; fissurd suhelongatd, sub- 
quadratd, intus subovali, callusd, exius iyiterdum vix Johatd. ex 
quadrante dimidium versus totm ah apice ad marginem longitu- 
dinis continud ; for amine lineis incrementi decussato apicem 
versus currente ; margine tenue creriulato. 

This shell would have been taken for the young of Glyphis 
insequalis, which in general appearance it greatly resembles ; 
but that fortimately the young of both that species and G. alta 
were found, differing in the following jiarticulars. In the 
Glyphides, the hole is close to the apex, comparatively large 
and solid,' and so arranged that as the hole increases, the apex 
is eaten away. In the Eimulre (of which 12 specimens were 
found of different ages) the slit occupies a portion extending 
from one-fourth to one-half of the entire length from apex to 
margin ; and though the largest shell is much larger than the 
Gh-phis, the apex still continues in the same relative position, 
and there is a channel rimning up to the vertical portion, 
shewing the lines of previous slits as in Pleurotomaria. The 
lines of growth on the young shell seem to shew that at one 
time it took the form of Emarginula, afterwards enclosing its 
slit. In this respect it is the reverse of Scissurella, which 
(as appears from specimens found in the Teneriffe dredgings) 
when young is like Kimula or Trochotoma, when adult like 



MAZATLAN UNIVALVES 223 

Emargintila. The plan of cancellation and tlie form of the slit 
differ somewhat in the specimens, but probably not specifically. 
The smallest shell, though scarcely '04 in length, displays a 
channel '01 long, as in the adult. The largest measures 
long. -125, lat. "07, alt. -035. 

Hah. — Mazatlau ; on Spondj'lus calcifer, extremely rare j 
L'pool Col. 

Tablet 1080 contains 3 sp. of different ages. 



Nihn. 



Family HALIOTIDyE. 

Family TEOCHIDtE. 
Genus CALLOPOMA, arai/. 

Fig. Moll. An. p. 87, no. 5 -.—PJiil. Eandh. ConcJt. p. 206 :— 

H. Sf A. Ad. Gen. i. 395. 
Turbo, sp., auct. — Distinguished by the extreme complexity 

of the operculum : v. infra. 

282. Callopoma (Tuebo) fluctuosum, Muwe. 

Turbo fluctuosus, Gray in Wood Suppl. p. 20, pi. 6, no. 44. — 

Mke. Zeit.f. Mai. 18-17, p. 179, no. 8: — do. 1850, p. 170, 

no. 2b.—Kust. Chemn. p. 60, no. 55, pi. 14, f. 3, 4 c. 
Turbo fluctuatus, Rve. Proc. Zool. Soc. 1848, p. 52 : — Conch. Ic. 

sp. 34, pi. 8, no. 34. 
Trochus (Turbo) Fokkesii, Jonas, in Phil. Ahhild. no. 1, pi. 2, 

f. 1, \0.— Midden. Mai. Ross. pt. ii. p. 86, no. 13. 
Callopoma fluctuatum, H. Sf A. Ad. Gen. i. 395, pi. 43, f. 7, 7«, 7b. 
Comp. Callopoma ? fluctuatum, var. depressum, Proc. Zool. 

Soc. 1855. ( = Turbo tvar. Bve. Conch. Je.pl. 9, f. 3 c.) = Turbo 

funiculosus, Kien. Icon. Conch, pi. 30, f. 1. 

Almost all the numerous specimens of this beautiful shcU 
fell victims, after I had first examined them, to the grindstone 
and acid. The exquisitely beautiful opercula were however 
thrown to one side as useless, and so preserved. These are flat 
and covered with a dark horny layer inside, displaying about 6 
whirls. Outside with a broad central spiral callus, wliite and 
granidar, concealing the umbilicus, with extrcmelj^ minute 
pustules over the surface, sometimes with a few sharp prickles. 
A deeply cut groove surroimda the callus, followed by a green 



224 MAZATLAN TTMIVALVES 

plaited spiral frUl, prickly inside. Betrveen this and the outer 
marf^in are 4 — 6 (generally 5) fine emerald necklaces, supported 
on slender spiral ribs, with deeply channeled interspaces. The 
margin and the body of the operculum are -white. The oper- 
culum of its neighbour, C. saxosum (Panama, C. B. Adams, 
S. W. Mexico, P. P. C.) is formed on a much coarser plan, 
with the central callus not covering the umbilicus, the frill 
rather granular thau plaited, the three rows of necklaces close 
together, without deep channels, and -with large granules on 
the margin. All the INIazatlan shells were of the tj-pical form, 
with the spire elevated, whirls well rounded, with distant rows 
of nodules. Whether the C. f. depressum is a variety of this 
form, (as I described it in the P. Z. S., copying lleeve's error 
in the name, and not aware that Eiener had figured it,*) 
or another species, cannot be decided without a knowledge 
of the operculum. The shell is distinguished ft'om all varieties 
of C. saxosum, by the non-corrugation of its surface. Long. 2 '56, 
lat. 2-5, div. 90'. 
Hah. — Punta St. Elena, Caming. — Mazatlan ; abundant; 

L'2Jool Col. — San Diego, Lieut. G-reen. — Sitka, JVosnessenslci , 

Middendorfi". 

Tablet 1081 contains the largest specimen, in its natiiral 
rough state. — 1082, the sp. which suffered least from hot acid. — 
1083, 6 opercula of different ages, and of exquisite beauty. 



Genus PHASIANELLA, Lam. 

Lam. Phil. Zool. 1809.— P/<//. Handh. Conch, p. 205. 
Eutropia, (Humph.) Gray, 1847.— jff. ^ A. Ad. Gen. vol. i. 

p. 389. 
Phasianus, Monlf. 1810. — TricoHa, Bisso, 1820. 

283. Phasianella peefohata, Phil. 

Zeit. f. Mai. 184S, p. 1(>1, no. ^L—Kust. Mart. p. 20, sp. 24, 

pi. 4, f 14. 
Comp. Phasianella tcssellata, Peck, 1838, Pot. ct. Mich. Gall. 

vol. i. p. 312, pi. 29. f. 7, 8.— C. B. Ad. Contr. Couch. 1850, 

p. 67.— Phil, in Ku.st. Mart. p. 18, sp. 22, pi. 4, f 12.— = Ph. 

minuta, Anton, 1839, Verz. p. 60, no. 2129, (non <So?«.)— = Ph. 

• I have 8een no letter-presg in explanation of the figure, nor are any dates 
given in Kiener's monognipbs, by which questions of priority can be determined. 



MAZATLAN TNIVALVES . 225 

zebrina, D'Ch^h. 1842, B. M. Cat. Cuba. Moll. p. 23, no. 256. 
(Jamaica, C. B. Adams ; Guadaloupe, J)' Orhiqny ; Cuba, 
Sagra.) 

Tliis beautiful shell closely resembles the W. Indian species. 
Like many of its congeners, it bas parallel diagonal lines of 
colour ; and is also variously and most beautifully stained with 
red and brown. The first whirl of the five is discoidal. It is 
characterized by extremelj- minute wrinkling over the whole 
surface, only discernible under the microscope, when quite 
fresh. The umbilicus is very large when young, and sharply 
keeled : when adult, it is often nearly filled up by the callous 
labium. Operculum radiately wrinkled over a large part of 
the outer surface ; within, spire produced, sharply keeled. The 
lai'gest specimen measures long. '13, lat. "12, div. 70". 

The smallest sp. „ „ '032, „ '037, „ OO". 

Kah. — Payta, Panama, E. B. Philippi. — Mazatlan ; 12 sp. 

among alga;, on UvanUla oUvacea, &c. ; L'pool Col. 

Tablet 108i contains 5 specimens shewing the principal 
varieties of coloui-, red, ashy and mottled, the largest of which 
has its operculum in situ ; also 2 separate opercula. 

283 b. Phasianella ? peefoeata, var. steittlata. 

P. t. " P . perforatce" simili, sed lineis coloris carente ; rufo 
punctata et varie maculatd ; striis sjnralibus intus nmblUcum 
et in basim, nonnunquam sujnxi spiram. 

Only two dead shells having been found agreeing in the 
above characters, their specific value cannot be tested. One 
of the specimens is very slender, the other of the ordinary 
fiirm. There is no trace of the minutely wi-inkled surface. 
Long. -09, lat. "07, div. 50". 

Rah. — Mazatlan ; 2 sp. in shell washings ; L'pool Col. 
Tablet 1085 contains the slender specimen. 

28i. Phasianella compta, Gould, ms. 

"Ph. t. parvd, soli da, ovato-conicd, imperfm-ata, politd, cin- 
eraseente, lineis minuiis oUvaeeis, oblique volventibus, ornatd ; 
anfractihus iv. [v.] rotundatis, ultimo ad peripheriam subangii- 
lato, et interdum tessellatim fasciato ; aperturd, circulari ; 
labro tenui, albo ; columella planulatd, albd ,- faucibm callo 
incrassatis." 



226 . MAZATLAN UXIVALVE9 

"Would accord pretty well with Ph. perforata, but is not 
perforate," at any rate in the adult state. Only one very dead 
shell and some fragments were found of this species, which 
appears to be sufficiently common on the Californian coast, 
where it represents the Ph. perforata of the tropical fauna. In 
the Sta. Barbara specimens, the colour and general appearance 
resemble the small variety of Ph. puUus. The operculum 
only differs from that of Ph. perforata in having the wrinkles 
rather coarser, and not covering quite so large a surface : this 
however may be only the effect of age. One of Dr. Gould's 
specimens from San Diego measures long. "22, lat. "13, div. &f. 
The Mazatlan shell is much smaller. 

Jffai.— San Diego, Mr. Blake ^ Br. Wehb.—Sta Barbara, off 
zoophytes. Col. Jeioett. — Mazatlan ; 1 dead sp. in shell wash- 
ings ; L'pool Col. 

Tablet 1086 contains the specimen. 



Genus BANKIVIA, Beck. 

Beck, in Krauss, Sudafr. Moll. 1848.— S". ^ A. Ad. Gen. i. 
^o.—Phil. Kandb. Conch, p. 212. 



285. Baxkivia varians, jun, Beck. 

Phil, in Kust. Mart. p. 33, pi. 5. f. 1—5. — Krauss, Sudafr. 

Moll.f). 105. pi. 6, f. 7. 
= Phasiauelhi fasciata, 3fke. S//n. Moll. Xov. Soil. ed. 2, p. 141. 
+ P. undatelhi, 3Tke. loc. cit. 
+ P. fulmiuata, Mke. loc. cit. — A7iton Verz. p. 61, no. 2137. 

One very young fresh specimen of this well marked shell was 
found on the back of a Chama. It exactly resembles young 
shells from Australia. How it had found its way from its 
native haunts, it is impossible to say. It is of the uniform red 
variety, with a dark sutural line. There are 4 turns of the 
spire, with a very flattened apex. Long. '0(S, lat. '05 ; diver- 
gence of last whirl 40" ; the next would probably be much less. 
Anton's name has precedence over that adopted by Krauss, 
teste Gray. 



MAZATLAN TNIVALVES 227 

Sah. — Australia, MeyiTce.—^ovAh. Africa, Kmuss. — Mazatlan ; 
1 very young sp. off Chama ; L'pool Col. 
Tablet 1087 contains the specimen. 

Genus UVANILLA, Ghay. 

Fig. Moll. An. p. 87, no. 8 -.—H. Sf A. Ad. Gen. i. 400. 
Iniperator, sp il/b/j//". a2?e^. = Calcar, sp. FJdl. Sand}). Conch. 

p. 107. — Distinguished by the want of umbilicus, and the 

bi-ridged operculum. 

286. UvAXiLLA (Impekatoe) olitacea, Mawe. 

Trochus olivaceus. Gray in Wood Stqjpl. p. 16, no. 3, pi. 5. — 

Xie)i. Ic. pi. 13. f. 2, fparva .)—Rve. Conch. Syst. pi. 217, f. 7.— 

T. (Calcar) ol. like. Zeit.f. Hal. 1850, p. 171, no. 2S.—Xusf. 

Mart. no. 226, p. 214, If. 103, pi. 32, f. 3, If. 84 (quasi Wood) :— 

do. loc. cit. f. 2, (quasi Rve.) 
Imperator olivaceus, P. P. C. Cat. Prov. et hie antea. 
Uvanilla olivacea, JS. Sf A. Ad. Ge7i. i. 400, pi. 6 a, 6 J, 6 p. 
=Trochus brevispinosus, Val. Voy. Ven. (non Lam.) — Chenu, 

Conch. III. 
= Trochus (Calcar) ervthrophthalmus, Phil, in Zeit. f. Mai. 

1848, p. ISS.—Knsf. ' Conch. Cah. p. 93, pi. 45, f. 3. 
Jun. ? = Trochus (Calcar) Melchersi, Mke. in Zeit. f. Mai. 

1850, p. 171, no. 29. 
Comp. Trochus Buschii, Phil: v. Zeit.f. Mai. 1848, p. 189, 

no. &7.—Kust. Mart. no. 265, lief. 103, p. 213, pi. 32, f. 1, 

lief. 84 (Panama.) — Kien. loc. cit. pi. 31, f. 1, 1 a. 

Philippi, having regarded the T. olivaceus of Wood to be 
distinct from that of Peeve, re-named the latter, which has a red 
pillar, T. erythrophthalmus. According however to the type 
in the collection of Dr. Gray, the red-tinted shell, figured 
as such by Peeve, is the true T. olivaceus of Wood, which 
name is therefore retained. — The T. Buschii, as figured by 
Kiener, almost exactly accords with U. olivacea ; but the 
outside is covered rather with corrugations than with slanting 
ribs : imibdicus faint red : base covered with obsolete rounded 
spiral costaj. 

Shell large, rather thin. Whirls rather swollen in the body, 
crossed by very numerous, slanting ruga', perpendicular to the 
labral margin, and generally continued to the periphery. This 
is expanded, winged, and armed with a very variable numbfer 
(20 or upwards) of vaulted tubercles. Base concave within the 



MAZATLAN UNIVALVES 



wing, SO that the expansion of each penultimate whirl lies 
closely over the next. A depressed portion, bounded by twu 
spiral lines, appears between the body and the wing, forming 
a false suture on the spire. Base with very fine striaj of 
growth ; with a nodulous spiral raised keel about the middle, 
and a nodulous line within, bounding the umbilical region. 
This is of a lustrous orange red, shading into black over a duU, 
sometimes slightly bifid spiral subcentral keel. The umbihcal 
mark is but moderately excavated, with a slight central cal- 
losity. Labrum extending one-fourth of a whirl. Parietal 
labium covering the inter-carinal region for another fourth. 
The rest of the sheU (base and spire) is covered with an 
oblivaceous epidermis, lying in strongly striated lines of growth. 
Colour beneath the epidermis dark green, more or less tinged 
with red. especially in the young shell. The medial portion, 
wing and tubercles, are often very slightly shewn in the adult. 
The shell when in good condition is extremelv beautifiil ; but 
it is almost always covered with animal and vegetable incrus- 
tations. It is subject also to the attacks of Lithophagi and 
Gastrochfenw. which generally have the instmct to burrow 
along the thick winged portion, or down the axis : but often 
venture to invade the liver-chamber in the upper whirls, when 
the Trochid withdraws itself, forming partitions as in Turritella, 
&c. Operculum smooth, outside with two strong ridges, begm- 
ning from nearlv the same point, and meeting at the other 
end ; of which the outer is far larger ; Avith a deeply-scooped 
hollow within ; and a faint ridge at the outer margin. Inside 
obtusely raised at the back of the large ridge ; with blackish 
brown "horuv covering. The largest sp. measures lo)iff. (from 
apex to wing at base) 2-9, lat. "26, div. 65". A spreading sp. 
lcng.1-9, Jaf. 2-lo, div.SCP. 

JBa&.— Mazatlan ; extremely abundant ; L'pool Col.—S. W. 
Mexico, P. P. C. 

Tablet 1088 contains 5 sp. different ages, spreading var.— 
1089, 5 do. usual form.— 1090. 3 do. very conical.— 1(X)1. 4 sp. 
after going tlirough the acid process, with the beautiful basal 
epidermis removed, but displaying the exterior markings.— 
1092. 4 sp. with ba?e beautifidly preserved.— 1093, 2 sp. mended 
after fracture.— 10i)l. 1 sp. with the mouth curiously distorted 
by an Ostrca coiichapliila. Each party has raised its lip to 
escape the other.— 1095. 1 sp. with Lithophagus aristatus m 
situ. Having bored through an empty barnacle as far as the 
interior,'it has increased outwards, making an external tube. 



MAZATLAN UNIVALTES 229 

287. UvANiLLA iNEEMis, Gmel. 

U.t. " U. olivacere" siniillimd; sed sculptura fortiore,rugis 
in spird distantioribus ; lined granularum inte^'nd in basi vix 
monstrarde ; regione umbilicali alba, cavitate profunda, carina 
spirali acuta circumeunte, extus vix excavatd ; eallositate termi 
diffusa. 

Trochus inerniis, Ghnel. p. 3576, no. 62.— Sckroet. Einl. vol. i. 

p. 719, no. 100.— Dilhv. Desa\ Cat. vol. ii. p. 787, no. 67.— 

Lam. Ati. s. Vert. vol. iv. p. 127, no. \7.—Kien. Icon. Conch. 

pi. 14, f. 2, 2 a. 
=Trochus olivaceus, Phil, in Zeit. f. Mai. 1848, p. 188 : non 

Gray in Wood. 

This shell, -n-hich was brought in some abundance by Capt. 
Kellett, is not the T. olivaceus, Wood, as Phil, seems to have 
supposed. There can hardlj^ be a doubt that it is the species 
figured by Kien. and therefore, it is presumed, of Lam. 
Whether it be that of the Linneean writers, can scarcely be 
determined, when the differences are so shght. 

It exactly remembles U. olivacea in almost aU respects : 
but has coarser, more distant rugse on the body of the whirls ; 
and in the umbilical region is white, more resembhng U. un- 
guis. Base V ith the inner row of granules scarcely developed : 
umbilicus deeply scooped, covered with a thin diffused callus, 
bounded by a sharp spiral ridge, scarcely scooped outside. 
The young shell has a fine keel in the place of the inner row 
of nodules, marked off by two faint spiral grooves, on the 
jnedial portion. "VYhether it be really distinct from U. oliva- 
cea must await a knowledge of the operculum, and a compari- 
son of additional specimens. The smallest sp., of 6 whirls, 
measures long, (apex to basal wing) •86, lat. '98, div. 80". 
Sa5.— Mazatlan ; 2 young sp. only ; L'pool Col. 

Tablet 1096 contains the youngest (mo^t charactea-istic) sp. 



288. UvANiiLA UNGdis, Mawe. 

Trochus unguis, Ilatve, in Wood Lid. Test. Suppl. p. 16, no. 2, 
pi. 5.—Rve. Conch. St/st. vol. ii. p. 165, pi. 217, f. 6.— Kien. 
Icon. Conch, pi. 13, f. 1 (max.) 

Turbo unguis, Besh. in Lam. An. s. Vert, vol ix. p. 224. no. 42. 

= Turbo digitatus, Lesh. Mag. de Chiir. 1841, pi. 36. 

= Trochus amictus, Val. Voy, Veniis. 

June 1856. ^ 



230 MAZATLAN UNIVALVES 

? = Trochus (Calcar) stellaris, Mke. (non Lam.) in Zeit.f. Mai. 
1850, p. 172, no. 30. 

This most abundant Mazatlan shell not being quoted by 
JVIenke in Lis catalogue, while the true T. stellaris (SteUa st. 
Gray) is a well known E. Indian shell, it is natural to suppose 
that his T. stellaris (which is published without a word of 
description) either belongs to this species, or has been im- 
ported. —7 The Cumingian specimens had (by an oversight) 
been marked T. uudosus. The true T. undosus, Muwe, (Wood 
Ind. Test. Sup})!. p. 16, no. 1, pi. 5. = Pomaulax u. G-ray*) is a 
very large Californian species, the singvdar triradiate opercu- 
hmi of which was found fresh in the S. W. Mexican collection. 
Shell yellowish white, somewhat silvery at the mouth ; more 
or less conical, with irregular, radiating, somewhat diagonal 
rounded plications, and often finely tubercular rugulse between; 
shghtly swollen next to the suture, and slightlj- concave above 
the periphery, but flattened in its general asi)ect. Base with 
rounded close spiral ridges (6 — 8 appearing) crossed by very 
close sharply-raised lines of growth, and faintly denticulating 
the base of the labrimi. Periphery with a variable number 
(14 — 18, generally 16) of roimded palmse, more or less projecting, 
more or less broad, concentrically furrowed by the basal ridges 
of growth, and not necessarily connected with the external pli- 
cations. Aperture with the labrum developed along half a whirl, 
imiting with the parietal labiimi which covers half the base, 
expanding over the umbilical region and ending in a raised 
portion below the axis. Colimiella with two spiral umbilical 
grooves, of waxen aspect, separated by a white roimded ridge 
ending in a tubercle just outside the mouth. The labnmi is 
indented by the exterior plications which are at right angles 
to its margin. The shell is rarely seen in jjerfection, being 
almost always covered, even when young, with a variety 
of Algre, CoraUines, Annelids, Bryozoa, Vermetidte, &e. ; and 
also, not unfrequently, attacked by Gastrochsena truncata and 
Lithophagus aristatus. Even the base," to the very edge of the 
labixmi, is frequently covered. The opercidum differs from 

* " T. nti'losug, Wood, is a Tcry much smaller shell than T. baljpnarum, Tal. 
Voy. Ten. and differs in the style and number of nodosities in the whirls. In T. 
baficnarum these amount in the last whirl to five rows, all much of the same size 
nnd round form. In T. undosus tliero are only two rows, and the upper of these 
are long, not round, and much larger than in T. balainarum." Baird. — T. balse- 
narum is generally regarded as a variety of T. undosus, in which the upper long 
row of tubercles is broken up into smaller rounded ones. If the two forms are 
however constant in .their respective provinces, they may bo representative species. 



MAZATIiAN VNIVAIVES 231 

that of U. olivacea in being sharper at tlie outer edge, more or 
less granular on tlie ridges (in tlie 5'ouug sliell over tlie whole 
surface), and with the small interior rib beginning within the 
other. Its apex fits against tjje peripheiy of the shell. A very 
finely grown spreading specimen measures long. V 2, laf.1'7, 
(without the pahnfe 1'36,) div. 80". The largest, conical sp. 
measures long. 1'73, lat. 1"8, (without the palmte 1'56,) div. 60". 
Sab. — Mazatlan ; extremely abundant ; L'pool Col. — S. W. 

Mexico, very fine, F. P. C. 

Tablet 1097 contains 5 sp. different ages, spreading variety.— 
1098, 6 sp. do. orduiary form.— 1099, 3 do. conical.— 1100, 3 do. 
sculpture clear. — 1101, 1 do. curiously mended after fracture. — 
1102, 1 do. upper part eaten awaj', leaving the liver chamber 
with the whirls disunited, like Vermetus. — 1103, 1 do. curiously 
crowned with Coralline. — 1104, 1 do. covered with Alga;. — 
1105, 2 do. bored by young Lithophagi. — 1106, 1 do. with large 
Annelid, of which an operculum is added from a full grown 
sp. on Spondylus, distinguished by the two large and two 
small branching stag's-horn processes. 

Specimens sheicing base. Tablet 1107 contains 3 sp., palmse 
broad, expanded. — 1108, 1 do. more distant. — 1109, 1 do. very- 
narrow. — 1110, 2 do. palma) numerous. — 1111, 3 do. iiTegularly 
developed. — 1112, 1 do. with labium narrowed by SabeUariae, 
which, along with Brj'ozoa contending with Vermetidse for 
superiority, have covered the base. — 1113, 1 do. with base 
curiously rounded. — 1114, 1 do. mouth blistered. — 1115, 1 do. 
with attachment of Calyptra3id outside the basal edge of the 
mouth. 

Tablet 1116 contains 2 sp. with the opercula in sitxi, one 
young, the other adult. — 1117, 6 opercula. 

Genus TEOCHTJS, Unn. 

Trochus, Linn., auct., pars -.—Pliil. Rand. Conch, p. 210. The 
ancient name is retained for these, the ordinary forms of the 
original genus. 

Ziziphinus, Leach .—JI. Sf A. Ad. Gen. vol. i. p. 421 -.—Mon. 
in Proc. Zool. Soc. 1851, p, 163. 

289. Tbochtxs veesicoloe, Mite. 

Zeit f. Mai. 1850, p. 172, no. 32. 

?= Ziziphinus Californicus, A. Ad. Proc. Zool. Soc. 1851, p. 168 
no. 52. 



232 MAZATLAN UNITALVES 

Comp. Trochus eximius. Rve. Proc. Zool. Soc. 1842, p. 185. 

(Payaua, sandy mud, 10 fm. Mus. Cmnmg.) 

This beautiful species is characterized in sculpture by a more 
or less sharp angular keel, at about 3-5ths of the breadth of 
the penultimate whirl, the whole surface being covered ^vith 
very fine subgranxdar spiral strife ; basal periphery- at a rounded 
angle ; base with about 9 distant, nearly smooth and scarcely 
raised striae. Colouring variegated with ashy and light orange 
brown, very rarely whoUy of a rufous tinge, stained about the 
granules and on the basal lines with lustrous piu-plish red, also 
with rich orange. The fh'st whirl is depressed, smooth, round- 
ed ; gradually passing into very coarse decussation, leaving 
deep pits between ; these pass into three strongly nodulous 
ribs, the lower gradually changing into a keel, small ones 
developing between the others, and both nodules and ribs 
gradually subsiding into the tj^pical state. The young shell is 
of a uniform orange brown or reddish tinge. Whirls 10. Veiy 
few specimens possessed the operculum, which is extremely 
thin, of many whirls (15 in a shell of 9 whirls,) with very 
delicate radiating strias, somewhat curved, and most developed 
near the margin of each whii-1. Long. 1', lat. '92, cliv. 65". 
Hah. — Mazatlan ; common ; Upool ^' Havre Coll. 

Tablet 1118 contains 4 sp. various ages. — 1119, 2 sp. extreme 
forms, div. 60''-80''. — 1120, 5 sp. shewing base and variations 
of sculpture. — 1121, 2 sp. with hermit crabs. — 1122, 1 sp. with 
operculum. 

Specimens shelving colour. — 1123, 4 sp. dark, variegation in 
large pattern. — 1121, 3 do. with narrow streaks of light. — 1125, 
3 do. nearly uniform, dark. — 112(>, 3 do. light and dark equal. — 
1127, 3 do. light predomiuatLng. — 1128, 3 do. nearly imiform, 
light. 

290. Tkochus Mac-Andee-d, n. s. 

T. t. subeleimtd, conicd, anfractibus convexiusculis, suturd dis- 
tinctd ; rubra, maculis pallidiorihus : liris spiralibus nodosis 
cinctd, in anfr. penult, vi. quarum inferiores ducepaullum majores 
.mnt ; interstitiis impressis, lirulis interdum intercalantihus ; 
tuberculis conferfis, rotundatis, extantihus ; peripherid vix an- 
gulatd ; basi lirulis vix granulosis, circiter xi. ornatd, inter- 
stitiis latis ; columelld hand insculptd, parum contortd, rcgione 
wmbiUcaU imprcssd . 
YxVL. t. rufo-fu^cd, U7idatim pallidiore ; basi rubra. 



MAZATLAN UNIVALVES 233 

Comp. Trochus minutus, Mke. in Zeit. f. Mai. 1850, p- 172, 
no. 31 : non Chemn. in Kiist. pi. 13, f. 16 (non 15.) 
Characteristic names being for tlie most part preoccupied in 
tliis extensive familj^ I liave felt at liberty to call this beautiful 
little species after a gentleman to whose personal researches 
■we owe so much of oxvc knowledge of the MoUusc-fauna of the 
Atlantic, and to whose kindness in the loan of valuable books 
and specimens I am under great obligations in the preparation 
of the present work. 

Shell somewhat resembling a variety of Trochus Antonii, 
Koch, in Phil. Ahhild. p. 2, pi. 1, f. 4 : which however has a 
few granular rows much larger than the rest, which are ex- 
tremely fine and far apart. The whole upper surface in T. 
Mac-Andreaj is covered with large tubercles. The base in 
T. Antonii is sculptured like the rest of the shell ; and the 
columella has a smooth scooped-out surface, which is wanting 
in this species. The Mazatlan specimen, perhaps immature, 
has 7 whirls. Lonci. '33, lat. '34, div. 70'*. The variety from 
Panama has 9 whirls, measuring '55 by '43. div. 60°. 
Bai.— Mazatlan ; 1 perfect sp. and fragments ; L'pool Col. — 
Panama, 1 sp. T. Bridges, Mus. Ciuning. 
Tablet 1129 contains the specimen. 

Genus OMPHALIUS, Phil. 

Zeit.f. Mai. 1847, p. 21 -.—Handh. Conch, p. 210. 

Omphahus + Chlorostoma, S. Sf A. Ad. Gen. i. 428,429:— 

Man. in Proc. Zool. Soc. 1851, p. 180. 
Trochus, pars, auct. Shell with a spiral ridge surrounding the 

umbilicus, ending in one or more tubercles on the columella. 

291. Omphalius ? EUGosus, var. bufotinctus. 

.P Chlorostoma rugosum, A. Ad. in Proc. Zool. Soc. 1851, p. 182, 

no. 26. 

O. frugosus, t. oUvaceo-fuscd, rufo .veii rufu-2nirpureo plus 
minusve tinctd ; testa jimiore sulcis spirallhus suhohsoletis, 
pauciorihus, radiatim prope suturam haud impressam rugoso- 
plicata ; lahro ad margincm olivaceo, rarissime aurantio tincto ; 
hasi sulcis crehriorihus ; testa adiiltd s(ppis.nme detritd. 

The C. rugosum was described from an unknown locality-. 
It appears in Mus. Cuming as from China, but without au- 



234 IIAZATLAN UNIVALVES « 

thority. The differences in the Mazatlan shells appear too 
trifling to found specific distinction upon them. The characters 
of the shell can only be seen in the young state ; in its ordinary 
form, it has the external aspect of the British Osilinus (Troc- 
hocochlea) hneatus ; from which the unibiHcated axis and 
nodulous columella at once distinguish it. Long. 1'17, lat. 1'08, 
div. 70°. 

JSah. — China, Mus. Cuming. [?] — Mazatlan ; very rare ; 
L'pool Col. 

Tablet 1130 contains the largest and smallest specimen. — 
1131, 1 sp. lip tinged with orange. 



292. Omphalitis vibiditltjs, Gmel. 

Trochus viridulus, Gmel. p. 3574. — Schreib. Conch, vol. . 

p. 24o.—I>inw. JDescr. Cat. p. 777, no. '^.— Wood Ind. Test. 

no. '12, pi. 28, p. 136. 
Omphalitis virididus, H. Sf A. Ad. Gen. i. 429. 
Globidus ex viridi et inibro variegatus, Chemn. vol. v. p. 114, 

pi. 171, f. 1677: — (non Trochus variegatus, Chemn. p. 101, 

f. 1661-2: — Dillw. p, 774, no. 35: — =T. Capensis, Gmel. 

p. 3573 : Hah. 'Cape of Good Hope.') 
Phorcus variegatus, A. Ad. in Proc. Zool. Soc. 1851, p. 156. 
= Trochus Brazihanus, Mice, teste A. Ad. loc. cit. 
+ Trochus B\Tonianus, Wood Suppl. p. 16, pi. 5, no. 17. 

(Hab. 'Sandwich Is.') 
Var. = Trochus reticulatus, Gould, ms. Cat. 
Comp. O. cruciatits, Gmel. (non Linn, teste Phil., Brazils) : — 

= 0. Brazilianus, Mke. = 0. BjTonensis, teste Mus. Cum. 

The single specimen which Mr. Cuming assigns to this very 
variable species, differs from all forms of O. ligulatus in the 
following particulars. Spiral lirre, both above and below, much 
fewer, with broad interspaces. Umbilicus somewhat cork- 
screw shaped, the parietal callosity being further off from 
the centre, while the spu'al ridge is nearer to it. It appears 
also to want the seminodulous callous ridge at the base of 
the labrtun. Colour dull red, slightly spotted with orange. 
Long. -U, lat. -76, (//r. 90". 
JJi/i.— Mazatlan. Col. Jewett.—Bo. ; 1 dead sp. ; L'pool Col.— 

San Diego ; very red variety ; Lieut. Webb. 

Tablet 1132 contains the specimen. 



*MAZATLi.N TINIVALTE3 235 

293. Omphalius ligulatxjs, Mke. 

Trochus ligulatus, Zeit.f. Mai. 1850, p. 173, no. 34. 

? = Pliorcus CaliforriicTis, A. Ad. in Proc. Zool. Soc, 1851, 

p. 157, no. 17 :— (Omphalius C.) S. 4' A. Ad. Gen. i. 439. 

[Phorcus, Hisso, teste A. Ad. = Omphalius, Phil. : teste 

P/M7. = Trochus Magus &c. = Gibbula, Zeac/i, S. ^ A. Ad.'] 
Comp. Phorcus liratus, A. Ad. he. eit. no. 15 : — (Omphalius 1.) 

JI. 4' A. Ad. Gen. i. 429. 

Shell about the shape and size of Phorcus (Gibbula) ciner- 
arius, which takes its place in the Atlantic fauna, as P. umbili- 
caris does that of O. viridulus. Outside crowded with more 
or less fine, more or less subnodulose spiral ridges, of which 
one or more are occasionally more develoj)ed than the rest. 
Tlmbilicus more or less open to the top, where the thin nuclear 
part is generally punctured. "WTiirls 7, of which the first three 
are smooth and flattened. Mouth slanting : parietal callosity 
near the umbilicus, not projecting ; columella between this 
and the spii-al ridge deeply sinuated ; spiral ridge ending in a 
broad diagonal callosity, close to which on the labiimi is a 
small tubercle, and at the base of the shell a large one. The 
area between these tubercles and the laj^er is rather deeply 
but shortly channeled. From the basal tubercle (ia the adult 
shell) runs a callus round the inside of the base of the labrum 
which is sometimes subnodulous. Between this callus and 
the outer lip is a well marked channel. Shell outside covered 
with a rough brown epidermis, conspicuous between the ridges. 
The shell, even when young, is generally covered with Annelids, 
Bryozoa, &c. Colour beneath the epidermis brownish purple, 
or ashy brown, spotted in shades. Operculum outside deeply 
concave, (div. 150",) of about 20 whirls, not thin, thickened at 
the margin, leaving a distinct suture, not striated ; inside 
glossy, of an orange horn colour. A specimen of ordinary 
growth measures long. -69, lat.'ll, div. 80<*. 

A flattened sp. „ -47, „ '93, „ lOO^. 

A conical sp. ,, '74, ,, '74, „ 70*. 

Sab. — Mazatlan ; common ; L'pool Col. 

Tablet 1133 contains 5 sp. whirls somewhat rounded, depres- 
sed. — 1134, 4 do. somewhat depressed. — 1135, 4 do. typical 
form. — 1136, 5 do. conical.— 1137, 5 sp. whirls flattened, depress- 
ed. — 1138, 3 do. ordinary form. 

Tablet 1139 contains 3 sp. ribs very fine. — 1140, 3 do. nodul- 
ous. — 1141, 2 do. curiously mended after fractiire.— 1142, 4 do. 



236 MAZATLAN tTNIVALVES 

with Bryozoa and Annelids attached. — 1143, 1 sp. with attach- 
ment of Calyptra;id. 
Tablet 1144 contains 4 opercula. 



294. Omphalius globulus, n. s. 

O. t. parvd, glohulosa, compacta, subconicd ; anfractibus v. et 
dimidium, quorum ii. et dim. primi sublceves, alteri spiraliter 
tenue lirati ; liris suhlcevibus, interstitiis latis ; peripherid hand 
angulatd ; umbilico haud magno, spiraliter ascendente ; callosi' 
tote paynetali haud coiispicud, ah axi suhdistante ; regione urn- 
bilicali subconcavo, liris spiralibusfortioribus ; columelld tuber- 
culo magno et callositate basali plus minusve distinctd munitd, 
prope eas profunde insculptd ; labro intus haud calloso ; sub 
epidermide tenui, Iccviori, pallide pwpureo-cinered, punctis et 
maculis purpureis pictd. 
Comp. Trochus glomus, Mkc. in Zeit. f. Mai. 1850, p. 173, 

no. 35 -• non TMl. in Kust. Mart. pi. 14, f. 15 (non 17 ; = 

Clanculus g. S. Sf A. Ad. Gen. i. 416,) 

This shell is much more derated and compact than the 
young of even the most conical variety of O. ligulatus ; in 
sculpture and umbilicus more resembling O. viridulus. Its 
characteristic features however are the absence of the tubercle 
which in O. ligulatus always borders on the spiral columellar 
callosity, and the deep channeling of the adjacent area. The 
size of the umbilicus varies sUghtly. Long.'Z, Za^. '33, div.SCP. 
Sab. — Mazatlan ; 5 sp. only ; L'pool Col. 

Tablet 1145 contains the most characteristic specimen. 



Genus VITEINELLA, C. B. Ad. 

Testa Margaritce, Cyclostremati sen Adeorbi formd simulans ; 
minima, albida, siihdiaphana, tenuis, plermnque subhyalina ; 
superjicie interdum Icevi, plerumque sculpturd varie ornatd ; 
anfractibus panels, quorum plures sculpturce desunt, normales 
i-ii., rapide augcntibus ; umbilico onaximo. 
Mon. Vitr. 1850 -.—Pan. Shells, p. 184 : (pars.)— P/«7. Sandb. 

Conch, p. 207.— JT. Sf A. Ad. Gen. vol. i. p. 434.— (Non Gray, 

B. M. Cat. Piilm. p. 65, 1855.) 

This genus, constituted by Prof. Adams for 5 species from 
Jamaica, (of which one, V. megastoma, is an Ethalia,) and 



MAZATIAIf tJNlVALYES 237 

enriched by 12 from Panama, (of whicli one, V. minuta, is a 
Teinostoma, as is also the PNeritina pusilla from Jamaica of 
the same author,) consists of a j^roup of exceedingly minute 
turbinate or discoidal shells, differing greatly in shape, but 
agreeing in colour and texture, which are white and subhyaliue. 
They have but few, rapidly enlarging whu'ls : the aperture is 
generally much dUated and sinuatcd ; the umbilicus is almost 
always large. They are either smooth and glossy ; or variously 
ribbed, keeled or striated. In some respects they resemble 
Cyclostrema, in others Adeorbis. Indeed manj* of the species 
could not be separated generically from the forms figured by 
the author of the latter genus, Searles Wood, Crag Moll., pi. 15, 
except by the textui'e. All the species examined agree in a 
remarkable disproportion between the nuclear and the adult 
parts of the sheU. While the usual number of whirls is four 
and a half, three of these are occupied with the unformed shell, 
which is smooth in the sculptured species, and distinctly mark- 
ed even in the glossy ones ; while only one, or one and a half, 
(very rarely two,) suffice for the full grown portion. From this 
circumstance it might have been supposed that they are all 
yoimg shells : but as they do not in the least resemble the 
young of any larger Mazatlan species, and as more than 150 
individuals were found, aU keeping to the same type, it is 
presumed that it indicates a peculiarity in the animal, which 
may serve to distinguish it from neighbouring genera. It is 
exceedingly to be regretted that Dr. Gray should have used 
the name over again last year for a genus of laud shells.* 
Among the species described as Eotellse by D'Orbigny and 
others (e. g. Globulus striatus, semi-striatus, pusUlus, carinatus 
and anomalus) are perhaps several Vitrinellse. Similar forms 
are also known fi-om the Eastern Seas. It is probable that 
the existing species are extremely numerous, though the indivi- 
duals are few. Although many of the Mazatlan specimens 
were perfectly fresh from their native haunts, not a trace of 
operculum was foimd. Of the described species, four are 
shewn by the types in Mr. Cuming's collection to be common 
to Panama and Mazatlan ; t fo\irteen appear now for the first 

• Dr. Gray proposes to alter the name of this latter genus to Vitrinula. 

t Besidps these may be seen in the Cumingian collection types of V. valva- 
toideg and Tciuostoma minutum from Panama ; and V. tincta, V. interrupta and 
Ethalia megastoma from Jamaica. The latter, along with a young Natiea Pcan- 
rena, wcro found with the specimen of V. interrupta. The indented species, 
ranked with this genus by its author on account of their teiture, accord better 
with Etlialia or Teinostoma, and do not display the characteristic difference 
between the earlier and later whirls. 



238 MAZATLAN UNIVALVES 

time ; seven are only known from Panama, and four from 
Jamaica. They are all of exquisite beauty. 



295. ViTRiNELLA Panamensis, C. B. Ad. 

V. t. siibdiscoided, majore, solidiore, alhd ; anfr. iv. et dimidio, 
quarum pcene duo normales ; anfr. primis IcBvihus, posted pente- 
gonatis ; carind maxime prominente vix super suttiram impres- 
sam ; carina satis prominente in spird, alterd sub peripheriam ; 
quartd mintis prominente in hasi, quintd iimbilicicm maximum 
eircumeunte ; supra et infra inter carinas clathratis, clathiHs 
(circiter xxii.^ subconcavis, interstitra quadrata, profunda for- 
mantibus ; totd superficie et iimbilico elegantissime spiraliter 
striatd, striis clathris superantibus ; aperturd vix rotundatd, a 
carinis angulatd, peritremati continuo, inter duas carinas anfr. 
penult, attingente, labro sinuato, postice expanso. 
C. B. Ad. Pan. Shells, no. 263, pp. 187, 316. 

One very fine specimen only \ras found of tliis (for the genus) 
large species, which has allowed of a description somewhat 
more in detail than that of Prof. Adams, who did not note the 
very characteristic spiral stria;. It is rather more elevated 
than V.parva, with an additional keel and deeper pits. Long. "03, 
lat. -065 by '057, div. 160". 
Sab. — Panama; 24 sp. in sand; C. B. Adams. — Mazatlan; 

1 sp. oflf Spoudylus ; L'pool Col. 

Tablet 1146 contains the specimen. 

296. VlTEINELIA PARVA, C. B. Ad. 

V. t. discoidali, spird planatd, anfractihus iv. et dimidio, 
supra et infra monstrantibus ; clathris quadratis, solidis, trans- 
versis instructd, jjIics mimisvc distantibus, xiii. ad xxii., a carinis 
spiralibus decussatis ; anfractihus junioribus Itevibus, postea 
quadrigonatis ; carinis duabus mediis, distantibus ; angiild 
tertidprope suturam, quartd regionem timbilicalem eircumeunte ; 
jugojuxta suturam et cavifate inter jugum anqulamque subcon- 
cavd instructd ; 2Jcritremati ab anfractu penultimo vix inter- 
ruptd ; labio angulaio, undulate, postice superante. 
a B. Ad. Fan. Shells, no. 264, pp. 187, 316. 
Vitrinella dathrata, P. P. C. Cat. Prov. 

The Panama shcUs in Cuming's collection have the transverse 
bars much more numerous than those from Mazatlan, and 



MAZATLAN UNIVALVES 239 

scarcely develop tlie umbilical angle, the want of which, in 
Prof. Adams' description had led me to overlook the species. 
It somewhat resembles V. Panamensis, and is known from the 
other Mazatlan forms by the stout radiating bars, crossed by 
two central keels, on which the shell will stand without support. 
There is also an angle at the shoulder, and a fourth bounding 
the large umbilical region. The shoulder angle projects so as 
nearly to conceal the spire. Close to the suture is a swelling 
ridge, with a depression between it and the angle. This part 
is wrinkled, not always so as to correspond with the bars, which 
are variable both in number and prominence. The lip does not 
always end with a bar. The lip is waved as in Adeorbis, but 
the texture is semidiaphanous, poreellanous white, as in Vitrin- 
ella. The mean divergence, if the shoulder angle were rounded 
off, would be about 170'. Long. '02, lat. -05, by -037. 
Hab. — Panama : 13 sp. in sand ; C B. Adams. — Mazatlan ; 

more than 30 sp. off Chamse and Spondyli ; L'pool Col. 

Tablet 1147 contains 5 sp. exhibiting the extremes of age 
and sculpture. 

297. ? VlTEINELLA DECTJSSATA, 11. S. 

? V. t. suhelevatd, turhiniformi, tenui, alba, porcelland ; an- 
fractihus'w. et diniidio, rotundatis, qiiarum '■m.pri'nii laves seu 
spiraliter striatl stmt, subito in superjiciem decussafani mutan- 
tes ; clathris extantibus quoad xv. spiralibus, transversis plus 
minusve distantibus, interstitiis valde impressis ; aperturd, 
adolescente peritremati haud continuo, labia paullum in umbilico 
rejlexo ; adultd circulari, continuo ; timbilico haud parvo. 

The true position of this shell cannot be determined till the 
animal and operculum have been examined. But for its tex- 
ture, which is that of Vitriaella, it might rank with Liotia. It 
ifl known at once by its Turbiaoid shape, and by the beautiful 
decussation caused by prominent transverse and spiral bars. 
The large proportion of this shell which does not display the 
characteristic sculpture would favour the supposition of its 
being a young shell. About 30 specimens however (perfect 
and broken) were found, of which the greater part were of 
uniform size. The smallest specimen is "022 across. The 
largest measures lojig. "04, lat. '045 by '035, div. 115". 
Hah. — ^Mazatlan ; very rare, off Spondylus ; L'pool Col. 

Tablet 1148 contains 4 perfect and 2 imperfect specimens^ 
shewing variations in age and sculpture. 



240 MAZATLAN CXIVALTES 

298. VlTEINELLA MOJflLE, n. S. 

V. t. suhelevatd, helicoided, diaphand, alba ; anfr. It. ef 
dimidio, convexis, quarum tres prhni Iceves seu spiraliter sub- 
striati sunt, subito in superjiciem minutissime decussatam mutan- 
tes ; liris quoad, xx. spirallbus, transversim decussatis, interstitiis 
subovalibus sen subquadratis ; aperturd spatiosd, peritremati 
continuo, pai'icm ab anfr. penult, impresso, labro ut in lanthinA 
sinuato ; umbilico anfractus intus vix monstrante. regione um- 
bilicali valde incurvata. 

This species is intermediate in form between "V. decussata 
and V. monilifera. The decussating structure, which covers 
the surface and enters the umbilicus, is extremely fine ; the 
suboval punctures (in a favourable light) appearing like rows 
of pearl necklaces. The adult portion rarely extends to a whirl 
and a half. Nearly 30 specimens were found, more or less 
perfect ; of which the smallest is " 023 across ; the largest 
measures long. '035, lat. "055, by '045, div. about 125". 

Sab. — Mazatlan ; very rare, off Chamae and Spondyli : L'pool 
Col. 

Tablet 1149 contains 1 imperfect, and 3 perfect specimens of 
different ages. In one, the spiral lines suddenly become more 
numerous. 

299. VlTEINELLA MONILIFEEA, n. S. 

V.t. "V. monili" sculpturd et indole simili, sed discoided, 
anfractibus sicb]}lanatis, decussatione tenuiore, umbilico maximo, 
anfractus ad apicem monstrante ; aperturd vix continud, sin- 
uatd. 

This species might without impropriety be ranked with 
Cyclostrema ; the apical portion however is as in VitrincUa. 
The mouth is scarcely altered in form by the penultimate 
whirl, and is sinuated as m Adeorbis. The necklace pattern is 
rather finer than in V. mouile. Long. *01o, lat. '04 by '035. 
Div. about 175". 

Hab. — Mazatlan ; 7 specimens in Chama and Spondylus ; 
L'pool Col. 

Tablet 1150 contains the largest and the most characteristic 
specimen. 



MAZATLAN UNIVALVES 241 

300. VlTBINELLA LTRULATA, 71. S. 

V. t. discoided, hand parvd, anfractihus iv. et dimidio, 
quarum tres insculpti, regularlter augentibus, spiraliter tenue 
Uratis ; spird planata, sivturis conspicuis, aperturd Irotundatd, 
umbilico maximo, anfractus monstrante. 

Distinguislietl from V. monilifera by its large size, more 
regular growth, and soinevv-hat coarser spiral lirse, whicb. are 
uot decussated. Tke mouth in the only specimen found is 
rather broken, but it appears to have been nearly round. It 
gives evidence of having been a coloured shell, and may pos- 
sibly be a Skenea. Loyig. "027, lat '085 by -065, div. 180. 
Sah. — Mazatlan ; i dead sp. off Chama ; Upool Col. 

Tablet 1151 contains the specimen. 

301. VlTKIXELLA SUBQT7ADBATA, n. S. 

V. t. discoided, albd, sen, subhyalind, planatd, Icevi, nitidd ,■ 
anfractibtis iv. et quadrante ; interdum stria juxta suturam 
impressam ; umbilico maximo ; anfractu ultimo prope umhili- 
cum et infra periplieriam- subangidato ; aperturd subquadratd, 
aijfr. penult, vix attingente, labro ad suturam et in medio valde 
sinuato, j)ostice dilatato, excurvato. 

In shape like V. monilifera, but without sculpture. Though 
smooth, the junction of the adult portion (one whirl and a 
quarter) is clearly marked. The aperture is beautifully sinu- 
ated in the middle and at the suture, with the labrum much 
excurved between the two. The smallest specimen is '025 
iieross. The largest measures long. '017, lat. '04 by "033. 
Div. about 175". 
Hah. — Mazatlan ; 16 sp. oflf Chama and Spoudylus ; Upool Col. 

Tablet 1152 contains 4 sp. differing in age and texture. 

302. VlTRIUELLA BIFILATA, 71. S. 

V. t. suhdiscoidied, anfractihus iv. et dimidio, rotundatis ; 
anfractu ultimo tenuissime spiraliter .striata, striis 'duabus, 
juxta et supra periphei'i am 7najoribus ; umbilico maximo ; aper- 
turd vix anfr. penult, attingente, vix subquadratd, labro ad 
suturam et in medio sinuato, postice excurvato. 

Differs from V. lirulata in the fineness of the sculpture, 
tumidity and comparative elevation of the spire, and in the 
development of two strise above the rest. Of these, the larger 
June 1856. x 



242 MAZATLAN UNIVALVES 

continues the subsutural line ; and the other, which is most 
conspicuous on j^ounger shells, being often nearly evanescent 
in larger specimens, appears on the spire. Th(? labrum ui 
this species also resembles Adeorbis ; and in one specimen is 
slightly thickened, producing a few varical ridges near the 
aperture. Another has the idtimate whirl abnormally depress- 
ed. Long. -025, lat. '055 by 'Olo, div. 160". 

Sab. — Mazatlan ; 4 perfect and 1 broken specimens off Chama 
and Spondylus ; L'pool Col. 

Tablet 1153 contains a beautifully perfect specimen, and a 
larger one with the varical mouth. 



303. VlTEINELLA BIFEONTIA, 71. S. 

FI t. subdiscoided, subdiaphand, nitente, puicherrimd, ai\fraC' 
tibus iv. et dimidio : carinis duabus Icevibus, maxime proniin- 
entibus, angidatis, sph'alibvs, quarum una infra, una sripra 
peripheriam sitcB sunt ; carina teriid inter eas, ad peripheriam, 
parum conspiciid ; carina quartd posticd, hand prominente, 
prope suttiram valde impressam, in spird decurrente ; ad um- 
bilicum maximum angulntd, hand carinatd ; basi subplanatd, 
striis duabus spiralibus, intus quadratim decussatis, extus decus- 
satione remotiore ornatd ; ad spiram striis inerementi irregu' 
laribus, rugulis intus umbilicum subcrenantibus ; aperturd 
quadratd, a carinis angulatd, hand nisi ad carinani basaletn 
anfr. j^enult. attingente ; spird subplaniitd, anfr. uU. decumbenfe. 

Variat carinulis spiralibus propc suturam intercalantibus. 

Variat quoque ad basim, striis spiralibus vix monstrantibus. 
rugulis usque ad peripheriam cequalitcr radiatitibus. 

Tn the form of the base and aperture and the wrinkles of 
growth, this species resembles Solariiim : in its two prominent 
keels and scarcely united whirls it luis relations with Bifrontia, 
(Omalaxis, If. Si" A. Ad. Gen. i. 21-1,) first discovered in a living 
state by the iudefatigable zeal of R. M'Andrew, Esq. The 
medial keel does not project beyond the tipper and lower 
ridges : the posterior keel is between the lower keel and the 
suture. The adolescent portion, which is as tisual nearly 
smooth, though angulatod at the spire, is almost concealed by 
the penultimate portion ; the last whirl however descends as in 
Delphinula, oniy touching by the anterior keel. The base ia 
normally ornamented witli two spiral lines, decussated in 
squares between ; with rarer decussating lines on the outer por- 



MAZATIAN UNIVALVES 243 

tion, and closer Tvrinkles entering the umbilicus. On one (dead) 
specimen however the radiating rug!B are coarse, not inter- 
rupted by spiral lines ; the periphery also is more adherent to 
the penultimate whirl. Four (perfect) specimens only were 
found of this exquisitely beautiful species. Long. "02, lat. '052 
by -043. Biv. about ITO". 
Hah. — Mazatlan : off Spondylus calcifer, extremely rare ; 

L'pool Col. 

Tablet 1154 contains one specimen. 

304. VlTEINELLA PEEPARVA, C. B. Ad. vav. NODOSA. 

Y. f. discoitlea, planata, quadratd, suhJij/alina ; carinis dtiahus 
ipirallbus infra et supra pevipheriam planatam, quarum postica 
nodosa ad marginem spiralem est ; bast rugulis radiantihus 
distantibics ornata ; carina pa rum expressa regionem timbili- 
calem magnam circumeunie ; apertura quadrata ; anfr. ult. 
Iiaud declivi. 

Pan. Shells, no. 265, pp. 187, 316. 
V. nodosa, P. P. C. Cat. Prov. 

The characteristic coronation of the upper keel is not men- 
tioned by Prof. Adams ; it is however very conspicuous in the 
specimen sent to Mr. Cuming. It is possible that the specimen 
he described is another species, in which case the name which 
I had giyen may be retained for tliis. It closelj^ resembles in 
outline a smooth, crenated Diuidry Ammonite. In Mr. Cum- 
ing's specimen, there arc one and a half normal whirls ; there 
also appears a slight labial deposit. The only specimen foimd 
at Mazatlan is unmatvire, and measures long. '0075, lat. '033 
by -027, div. 175". 
J£ab. — Panama ; 3 sp. in sand ; C. B. Adams. — Mazatlan ; 

1 sp. off Spondylus ; Bpool Col. 

Tablet 1155 contains the specimen. 

305. VlTEINELLA EXIGUA, C. B. Ad. 

V. t. suldiscoidea, albd, anfractihus iv. et triente ; carinis iii. 
maxime promitienfibiis, acutis, angulatis, hand serratis, quarmn 
una ad peripkeinam, una antica, una postica in spird sitee sunt ; 
angulo circa umhilicum magnmn phis m inusve monstrayite ; striis 
exillimis spiralibus totd super/lcie ornatd ; lirulis radiantibus 
plus minu^ve distantibus et infra et supra decussantibus, circa 



244 MAZATtAN UNIVALVES 

umbilicitm et inter carinas centrales evanidis ; aperturd a 
carinis angulatd, inter duas carinas avfr. 'permit, attingente ; 
anfr. ult.plus minusve decicmbente. 
Fan. Shells, no. 259, pp. 184, 315. 

Having written tke above description (under the name of 
V. trigonata), a minute examination of the type specimens in 
Mr. Cuming's collection proves them to be identical with the 
Panama shell. It is remarkable that Prof. Adams has not 
mentioned the stout keel above the periphery, nor the crowded 
spiral stria; over the sm-face, which however are clearly- marked 
on his specimens. If there are similar omissions in other 
diagnoses, it may be that some of the other species have been 
before described. The tr\'pical markings are with transverse 
riblets, about 20 to the whirl, on the outer half of the base, and 
between the keels on the spire : but in one specimen are nearly 
double that number. The spiral strise are over the whole 
surface. The keels are sharp, smooth, and extremely promin- 
ent. It is difficult to estimate the divergence, as it depends 
on the depression of the last whii'l, which in one of the adult 
specimens makes the angle 150", in the other 170". Long. '025, 
lat. -06 by '05. 
Hah. — Panama ; 7 sp. in sand ; C. B. Adams. — Mazatlan ; 2 

adult and 4 young sp. off Spondylus and Chama ; L'pool Col. 

Tablet 1156 contains the most characteristic specimen. 

306. VlTEINELLA COKONATA, M. S. 

V. t. " V. exiguce" simili, sed discoided, striis spiralibus nisi 
in umbilicum nullis, seu evanescentibus ; hasi prope umbilico 
valde angalato ; cannd media maxiine extante ; rugis radianti' 
bus, injuniore valde extantibus, intus carinam basalem, et supra 
spiram, caAnam posteriorem in spird superantibus, quasi caron- 
antibus. 

The distiaguishing radiating rugae which cross the keel on 
the spire and give it a serrated or coronated appearance are 
very conspicuous on the yoimg shell ; but, along with those 
on the base, they become evanescent as the shell amves at 
matiirity. The species is further distinguished from V. ex- 
igua by the absence of spiral stria; except in the umbilicus ; 
and from both this and V. tricarinata by its extremely depress- 
ed growth, the upper keel completely hiding the spire. Only 
one perfect and 3 imperfect specimens were found. Long. '02, 
lat. 055 by •ai5, div. 185". 



MAZATLAX trxiVALTES 245 

Sab. — Mazatlan ; extremely rare, off Spondylus and Chama : 
L'pool Col. 

Tablet 1157 contains the perfect specimen, and the youngest, 
with, the rugse conspicuous. The other tno specimens found 
were intermediate between these extremes. 

307. PVlTEIXELLA ANNULATA, n. S. 

?V. t. suhglohosd, solidiare, opaca, alba, anfractibus \\. et 
triente ; spird haud depressa, Icevi ; carina spirali ad peri- 
pheriam conspicud, rotundatd ; cariyiis dztabus minoribu^, acv.th-, 
quorum altera nmbilicum satis magnum dejinat, altera inter- 
media est ; aperturd suhrotundatd , a earinis subangulatd, anfr. 
penult, parum attingente ; suturd subimpressd ; siriis nonnullis 
spiralihus in spiram monstrantihus. 

This shell is somewhat solid and globose for the genus ; and 
the nuclear portion not being clearly defined in the solitary 
specimen found, its position is doubtful. It is easily recog- 
nized by the rounded, annular keel on the periphery, with 
two somewhat sharp ones on the base, the latter bounding the 
umbihcal region. Loiig. •027, lat. •052 by '047, div. 150". 
Sah. — Mazatlan ; 1 sp. off" Chama ; L'pool Col. 

Tablet 1158 contains the specimen. 

308. VlTEIJfELLA CIXCTA, n. S. 

V.'J. suhglohosd, alba, anfractibus iv. tumidis ; earinis duahus 
majorihus, acutis, haud valde prominentibus, haud distantibus. 
vtroque latere peripherice planatce spiraliter cingentibus ; duahus 
quoque ill basi minoribus ab umhilico profunda, haud expanso, 
ct peripherid cequidistantibus ; spird suhplanatd ; striis passim 
spiralihus; apertvrd a earinis angulatd, anfr. penult, parum 
attingente ; regione inter umhilieum ipsum et carinam profunde 
concavd ; anfractu ultimo parum declivi. 

The two principal keels are much closer and less prominent 
than in V. bifrontia. In the base it resembles \ . annulata, 
but the spiral portion is quite different, being flattened, with 
verj' numerous spiral stria?, The whirls do not enlarge rapidly. 
The umbdicus itself is somewhat narrow, with a broad funnel 
leading down to it from the nearest keel. The labium is some- 
what reflexed over it. Long. -Qrl, lat. "034 by •028, div. 170. 
Hab. — ]\Iazatlan ; 1 sp. off Spondylus ; L'pool Col. 

Tablet 1159 contains the specimen. 



246 MAZATLAN UNIVALVES 

309. VlTSINELLA CAEINTJLATA, n. S. 

V. t, suhglohosd, suhdepressd, tenui, suhdiaphana ; suturd im~ 
pressd ; uinhilico hmid magno ; regione umhllicali jnagnd, 
concavd, ra.iiaiim 7'ugosd ; avfr. tilt, carinulis v. haudpromin- 
eniihus, quarum dues infra et supra per ipheriam haud planatam 
Slice sunt, dure in spird haud planatd, altera regionem umhili- 
calem describens ; sulcis spiralibus in hasim, carinulis simu- 
lantihus ; aperturd subelongatd, ad basim angulatd, anfr. penult, 
parum attingente. 

Known from V. cincta by the non-promiuence of the keels, 
rounding and keeling of the si^ii'e, and greater elevation. The 
only specimen found is not mature, scarcely a whirl being 
formed of the adult portion. Long. "22, lat. '03 by "023. 
div. circ. '165°. 
JTab. — Mazatlan; 1 sp. oiF. Spondylus ; L'pool Col. 

Tablet 1160 contains the specimen. 

310. PVlTBINEIiLA NATICOIDES, n. S. 

? V. t. subglobosd, aubdepressd, nitidd, suhdiaphand, albd ; 
anfractibus iv. et trientc, quarum primi convexiuscuU sunt, 
ultimi siUurd vix impressd ; striulis increments exilUmis, max- 
ime sutwram versus, haud conspicuis ; umbilico prqfimdo, an- 
gusto, a carina extante callosd dqfinitd ; aperturd anfr. penult, 
parum, attingente, lahio subcxpanso, a carhid angulato. 

This curious shell might be either called by the above name 
or Natica vitrinelloides. as it partakes of the characters of 
both genera ; though the textiu'e and difference of convexity 
in the first three whirls iiicline the balance in favour of the 
former genus. Thus the shell alone cannot decide between 
animals widely removed. It looks like a flattened, white, 
glossy Natica, with the straight umbiUcus bounded by a con- 
spicuous keel which runs into the aperture. Long. '03, lat. .0^ 
by -04, div. IGO". 
JTaJ.— Mazatlan ; 2 sp. off Spondylus & Chama ; Lpool Col. 

Tablet 1161 contains tlie largest specimen. 

311. PVlTRINELLA PLANOSPIEATA, n. S. 

?V. t. magnd (quoad genus), tcnuissimd, subdiaphand, albd 
.tpii'd planatd, ad carinas valde angulatd, spiraliter striatd 
ad basim tumonte, convexd, profunde sed no.-i late nmhilicaid 



MAZATLAN UNIVALVES 



247 



had et v.mhilico spiraliter liratis ; ad peripheriam carina acutd, 
promiiiente, altera spvram ascendente, minus irrominenfe ; inter 
eas sutura valde impressa ; aperturd anfr. penult, vix ad cari- 
■nam attingente. 

Tliis very remarliable sliell lias the general appearance of 
Helix (Iberus) Gualtcrianus. It has however two keels, (that 
on the spire being less prominent) and a deep rather narrow- 
umbilicus. The whirls rapidly increase in size both in breadth 
and thickness. The generic position is doubtful, the only 
specimen found having lost the greater portion of the last 
whirl. The general aspect and texture are like a very large 
Vitrinella, and the usual unformed portion is clearly defined, 
being much larger than in the tjijical species ; it differs how- 
ever in the comparative length of tlie adult part, which must 
have consisted of at least two complete whirls. The shell 
when perfect may have been "2 in length : the penultimate 
whirl measures long. '03, lat. "04 by '025, div. 180". 

^a6.— Mazatlan ; 1 broken specimen off Spondylus calcifer ; 
Upool Col. 

Tablet 1162 contains the specimen. 

312. ? Vitrinella orbis, n. s. 

? V. t. discoidea, diaphand, hyalind ; valde complanatd, 
spird planatd, hasi suhpUmatd ; ad peripheriam rotundatam, 
et intus umhilicum apertissimum, striis spiralibus paucis, plus 
minusve impressis ; infra-et supra Icevi, interdum stria spirali 
juxta siituram hand, impressarn ; avfractit ultimo penultimum 
parum attingente ; aperturd angustd, spiraliter elongatd, sub- 
quadratd ; lahro simtato, postice producto. 

This singular species has relationship to Discohelix, Dkr. 
Palaont.\.Vi2,, = Ovhm, Lea; of which, as of Vitrinella, the 
animal is unknown, being classed with Littorinida) by Phil. 
Handb. Conch. p.'l74, but with Architectonicida) by H. Sf A. 
Ad. Gen. i. 2M. It has the appearance of the common flat 
Dundry Ammonites, with the periphery rounded and spirally 
striated. A beautifally perfect specimen, quite transparent, 
but probably immature, was found inhabiting the spiral portion 
of a dead Isapis macidosa, the mouth of which had been choked 
up with coralline, among the debris of a Spondylus. It 
measures long. "OOJa, lat. '033 by "027, div. ISO''. Three 
other broken specimens wore found on Chamse. 



248 MAZATLiOI TTNIVAtVES 

Hah. — Mazatlan ; extremely rare, on Chama and Spondylus ; 
L'pool Col. 
Tablet 1163 contains the perfect specimen. 



Genus PLIOTIA, Gray, 

&jn. B. M. 1840— S". Sf A. Ad. Gen. vol. i. p. 404.— PAiZ. 

Ranih. Conch, p. 206. 
DelpLdnula, pars, auct. 

The following slieUs are ranked doubtfully witb tbis genus, 
not having the expanded lip of the typical species, and the 
opercula being unknown. 

313. ? LlOTIA CAEINATA, n. S. 

?L. t. soUda. cinered, rufo tincta ; spird depressd, anfractibu^ 
iv. supra suhplanatis, sutiird distinctd, angidata ; catnnis iv. 
extantihtis circa peripheriam ; Uris spiralihus iii. in spird, 
nodidosis ; ni. in basi rotiindatd, haud extant ibiis ; circa um- 
hilicicm magnum radiatim rugoxo-nodosd ; aperturd intus circu- 
lari, anfr. penult, parum attingente ; anfractu ultimo valde 
decumbente. 

Shell comparatively solid and opaque ; it may be young, but 
from the small size of the nuclear i)ortion and the sudden 
declension of the last whirl, it is presumed to be uearlj- mature. 
Long. -03, lot. 'Oio by "Oi, div. (anfr. penult.) 175". 
Sab. — ^Mazatlan ; 1 sp. on Spondylus ; L'pool Col. 

Tablet 1164 contains the specimen. 

314. PLiOTIA STBIULATA, W. S. 

?L. t. turhiniformi, spird subelevatd, albidd, solidd ; anfracti- 
hus iii. rotundatis, radiatim exillime et cot\fertissime stnulatis, 
carinis parum cxfantibus iii. spiralihus; umbilico niagno ; in 
basi interdum rugis radianiihus ; aperturd declivi, solidissimd, 
intus rotundatd, anfr. penult, parum attingente. 

The thickness of this little shell is extraordinary, being at 
the posterior portion of the aperture nearly '005 in. The 
■whirls are rounded, obscurely carinated, and most minutely 
and closely striated in the direction of growth. Long. "027, 
lat. -037 by '03, div. 130". 



MAZATIAN TTNIVALTES 249 

Sab. — Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 
Tablet 1165 contains the specimen. 

315. ?? LiOTiA C-B-Adamsii, n. s. 

?? L. t. tenuissima, diaphand, alba; turrifd, anfractihus iii. 
tumenfibus, s^upenie stibangulafis ; liria radiantibus (in anfr. ult. 
xxii.^ a liriilis .^piralibus circiter viii. nodulosis elegantissime 
cancellatis ; anfr. primo et dimidio Icevibus, tumentihus ; liris ■ 
radiantibus in basi evanescentibus ; utnbilico parvo ; apertura 
subcirculari, peritremati continuo, ab anfr. penult, vix inter- 
rupt o. 

Although this is clearly a yonng shell, its characters are so 
well marked and distinct from any other known Mazatlan 
species, that it has been thought best to preserve a remem- 
brance of its beauty in connexion with the name of the most 
accurate and deeply lamented Prof. C. B. Adams. It has the 
texture of Yitrinella, but is distinguished by its tiu*rited form, 
and by the large size and short length of its apical xjortion, 
which occupies a whirl and a half, instead of three minute 
whirls as is customary in that genus. The rest of the shell is 
beautifully decussated by radiating lir<T, obsolete on the base, 
knotted by revolving lirulae, three of which appear on the base. 
Both labrum and labium are extremely thin. It may possibly 
belong to Eissoidee. Long. "024, lat. "022, div. 70°. 

Sah. — Mazatlan ; 1 young sp. off Spondylus ; L'pool Col. 

Tablet 1166 contains the specimen. 



316. ? LiOTiA , sp. ind. 

Tablet 1167 contains a fragment of a somewhat elevated 
shell, with the apex flattened. The first whirl is large and 
smooth as in PPL. C-B-Adamsii ; but the sculpture is extremely 
strong, with stout transverse tubercular ridges and spiral 
decussating lira;. It is distinguished from Chrysallida by the 
flat, dextral apex. 

Hob. — Mazatlan ; 1 sp. off Spondylus : L'pool Col. 



250 MAZATLAN TTNIVALTES 

Genus GLOBULUS, Schum. 

Schumacher, Essai Sfc. 1817, no. 23 .- (non Sow.). — Phil. Sandb. 

Conch, p. 208. 
Eotella, Lam. 1822, et auct. 
Umbonium, Link; A. Ad. Mon. in Proc. Zool. Soc. 1853, 

p. 187 -.—JI. Sf' A. Ad. Gen. vol. i, p. 407. 
Pitonellus, Monff. 
Helicina, (Lam. a prima manu) Gray in Proc. Zool. Soc. 

1847, p. 146. 

317. ? Globulus tumens, n. s. 

? G. t. glohosd, solidittsculd, alba, suhnitente ; spird planatd, 
depressd, aiifractihus iv. suturd haud impi-essd ; striulis spira- 
libus suhobsoletis temdssime ornatd ; callositate valde tnmente, 
trientem partem basis teqente, sutti^'d impressd, umbilicuin 
legente, in parietem et intus siituram spiralem ascendente, juxta 
labium vix planatum ; aperturd intus rotundatd, labro in 
spiram ascendente. 

This species is iatermediate between tlie typical Globuli and 
the Ethali?p. In the faint sculptui-e and slight planing off of 
the callosity, it presents the characters of the latter genus ; 
in the large swelling growth of the callus, which appears glossy 
over the whole surface, and covers the body whirl within the 
mouth, running up to the suture, it is a true Globulus. Two 
older specimens were found, sufficicntlj^ agreeing in other 
respects, but displaying a groove in the callus near the base of 
the columella, exactly in the same place, Avhich is remarkable 
if accidental. They are both however worn specimens. If it 
should prove a constant character, they may take the name 
of "G. sulcatus, f. callo basim versus subprofunde sulcato." 
Long. -013, lat. "038 by -033, div. 160". 
Huh. — Mazatlan ; 3 sp. off Chama and S.pondylus ; L'pool Col. 

Tablet 11G8 contains the fresh specimen, and one of the form 
G. sidcatus. 

Subgenus ETHALIA, H. Sf A. Ad. 

Gen. vol. i. p. 409 -.—Proc. Zool. Soc. 1853 (Mon. Umb.J p. 189. 

A small group of Mazatlan shells, of the general aspect of 

Vitriuellffi, and agreeing with Globulus in having a callous base. 



MAZATLAN TJNIVALVE3 251 

differ from the typical species of that genus (1) in being fre- 
quently sculptured, (2) in the eaUus winding round, generally 
not covering the umbilicus, (3) in the outside of the callus not 
being glossy, but having a glossy portion scooped out near tlie 
columella. The labium is generally not reflected over the 
body whirl. Thej' appear to retain permanently the young 
state of Teinostoma. At the same time, the specimens examin- 
ed were so few (only 9 of 5 species) and some of these were 
to such an extent intermediate between other groups, that it 
is impossible to designate them with confidence. Some of the 
small white shells described as Rotell£e are probably referable 
to this form. IVIr. Cuming states that the species he found 
were deep water shells, while the true Globuli are littoral. 

318. Ethalia pteicallosa, n. s. 

E. t. valde depressd, alhicld, opaciore ; anfracUbus iv. et 
dimidio, quarum tres p>'i;«i Iceves sunt, suturd hand impressd ; 
striis spiralibus tenuihus, rugulisque incrementi tenuissimia 
elegantissime ornatd ; callosifate opacd radiatim rugosd circa, 
umbiliciim parvum gyrante, jv,xta labium planatd, pyriformi $ 
aperturd stcbovafd, labro tenui, intus suturam vix callosd ; labia 
ni aiifractu pcnuUimo liaud expanso. 

This extremely elegant and characteristic shell agrees with. 
VitrtneUa in the nature of the apex ; but differs in the revolv- 
ing callus, which is not covered with the spiral strise, but 
radiately wrinkled ; at the aperture it is suddenly j)laned off, 
displaying a pj'riform shape. Long. '019, lat. "Qi? bv '037, 
div. 160". 

Hah. — Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 
Tablet 1169 contains the specimen. 

319. Ethalia lirulata, n. s. 

E. t. depressd, albd, opacd ; anfractihns iv. quaitim primi 
IcBves sunt, suturd hand impressd ; striis spiralibus tenuibus 
confertissimis ; callositate opacd, circa rimulam umhilicalem 
gyrante, juxta labium planatd, lata, suhtrigond; aperturd ob- 
ovali; labro tenui, ii^ra sutwram minime callosd ; labia inpanete 
nullo. 

Known from E. pyricallosa by the compact growth, close 
stria) without transverse wrinkles, and short broad callus 



252 MAZATLAN TTNIVALVE8 

which covers the umbilicus, leaving only a slight chink. A 
second sp. agrees in aU respects except that the spiral sculp- 
tui'e is coarse and somewhat moniliform ; but it is too much 
weathered to decide on its affinities with confidence. Long. "019, 
lat. -039 by -034, cUv. 1.53». 

Hah. — Mazatlan ; 2 sp. off Chama and Spondylus ; L'pool Col. 
Tablet 1170 contains the typical specimen. 

320. EtHALIA PALLIDULA, n. s. 

E. t. glohosd, solidd, alba ; ad spiram planatd, ad hasim pro- 
ductd ; anfractihus m.., suturd indistiiictd, ap ice planatd ; fold 
superjicie striis spiraUhus suhrugulosis impressd ; callositate 
minimd ; umbilico nulla ; aperturd elongatd, ad hasim .sub- 
angulatd ; labro acutiore, labia canspicuo. 

A little globular shell, produced at the base of the columella, 
and presenting the general aspect of the young of Lacuna 
pallidula. It is on the extreme verge of the genus, tihe com- 
pact spire preventing the development of the callus. Lang. "029, 
laf. -Oiiby -035, div. 170". 
Hab. — Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 

Tablet 1171 contains the specimen. 

321. Ethalia caeinata, n. s. 

JE. t. discoidali, planatd, aurantio-fuscA ; anfractihus iv. et 
dimidio, qiiarnm iii. primi Iceves, vix amplectentihus, suturd 
valde impressd; siih peripheriam acute carinatd ; tatd super- 
ficie rugulis incrementi confertissimis ornatd ; regione umhilicali 
co7icavd ; callositate spirali elongatd, angustd, rimam conspicu- 
am umbilicalem gyrante,jua:ta labium parum planatd ; aperturd 
subquadratd, sinuatd. a cariud angulatd ; labia ad parieiem 
nulla ; labro intus suturam parum calloso. 

This charming little shell has the general aspect of Planorbis 
carinatus, but with the whirls a very little elevated, and the 
keel just below the centre. The whirls very slightly embrace, 
but are cemented by the long, thin callus. Both above and 
below, it is covered with extremely close, rugulous, radiating 
striula;. In its mode of growth it affords a transition to Teino- 
stoma. Long. 013, lat. 038 by "033, div. 175". 
Hab. — Alazatlan ; 2 sp. off Spondj'lus ; L'pool Col. 

Tablet 1172 contains the freshest (but smallest) specimen. 



MAZATtAN TJNITALTES 253 

322. Ethalia amplectans, n. s. 

E. t. minima, plauatd, diaphand, nitidissimd ; anfractibus 
iii, planatis, pcritremafi rotundato ; callositate haud parva, 
umhilicum vix iegente,juxta labium planatd, semilunatd ; labro 
acuto, supra anfractiim x)&nultimum dilatato ; infra suturam 
haud impressam callositate, suturam fallacem extus simtilante ; 
aperttird rotundatd. 

As it is barely possible that this shell may be the young of 
Teinostoma amplectans, the same Specific name has been given. 
It differs however in the much smaller size of the callosity, 
which in this shell displays a broad, semi-lunate planation at 
the columella, which appears characteristic of the species. 
Long. -016, lat. -01 by -032, div. 180". 

Sab. — Mazatlan ; 4 sp. off Spondylus ; ISpool Col. 
Tablet 1173 contains the freshest specimen. 



Genus TEINOSTO^IA, A. Ad. 

JProc. Zool. Soc. 1853, p. 183.— S". ^- A. Ad. Gen. vol. i. p. 122. 
Testa spird depressd, politd, anfracfibics rap/de augentibus ; 
regione umbilicali callosd ; aperttird product d. elongatd, ab axi 
remotd ; interstitio calloso ; periiremati axin versus rotundato, 
ad pcripheriam interdum angulato. 

Shell Eotelloid, with a greatly produced mouth and callu?. 
It resembles Cyclops among the Nassida*, and in the appear- 
anco of the base reminds the observer of Streptaxis and 
Anostoma among the HelicidcB. Having been described (in 
English only) from a single species (T. politum, St. Elena, 
8 fm. Cuming,) some of the characters before given may here- 
after prove to be only specific. 

323. Teinostoma amplectans, n. s. 

T. t. parvd, alba, planatd, Iceoi ; 2^enti'emati rotundatd ; 
callositate spirali umbilicum tegente, labium versus subplanatd, 
supra parietem intus suturam decurrente ; aperturd rotundatd ; 
labro supra anjr actum penultimum rejlecto ; suturd haud' 
impress d. 

Although the shells described above as Ethalia may possibly 
be the young of this species ; yet, as thej were aU of tho same 
June 1856. ^ 



251 MAZATTAN UNIVALVES 

size, and there were no intermediate specimens, I have not ven- 
tured to affiliate them. It diiFers from T. politum in the 
absence of sculpture, (which however would hardly be detected, 
even under the microscope, without the description,) in the 
greater reflection of the labrum over the spire, and in the very- 
much smaller size. Long. 'Ob, lat. '11 by '07, div. 180". 
Sab. — Mazatlan ; 1 sp. and fragment off Spondylus ; L'pool 
Col. 

Tablet 1174 contains the specimen. 

324. Teinostoma STrssTKiATrM, n. s. 

T. t. minima., 2^l(inatd, opacd, alba, suhnitenfe ; striulis 
spiralihus prope suturam impressam monstrantihus ; callositate 
angustissimd, longioi'e, circa rimam umbilicalem gyrante, prope 
labium vix planato ; apertura rotundatd ; labro solido, anfr. 
penult, liaud amplectante. 

This tiny species is known from T. amplectans by the outer 
lip not being reflected over the spire, which clearly displays 
the Bubstriated whirls. The callosity is long, but narrow, and 
scarcely planate at the aperture. A fragment has the suture 
less inyjressed. Long. '016, lat. '043 by "032. div. 170°. 
Sab. — Mazatlan ; 1 sp. (not quite perfect) and a fragment ; 

L'pool Col. 

Tablet 1175 contains the specimen. 



325. TEOcHrs , sp. ind. 

Tablet 1176 contains a fragment of a white shell, tuberculous, 
with the basal keel smooth ; found in additional materials 
after the genus had been completed. 
Hab. — Mazatlan ; extremely rare, ofl Spondylus ; L'pool Col- 



Tablet 1177 contains an operculum not affiliated to any 
known multispiral species. (That of species 291 is however 
unknown.) It is light horn-coloured, extremel^^ thin, with 
only about 10 whu-ls ; margin irregular ; scar lateral. 

Tablet 1178 contains 2 worn, small, strong, Turbinoid opcr- 
cula, remarkable for the number of whirls, there being at 
least 10 in a diameter of "046. 



MAZATLAN TTNIVALVES 255 

Tablet 1179 contains 2 rubbed opercnla, wliicb may have 
been waslied up from young Callopoma saxosum. 

Tablet 1180 contains a shelly operculum (apex broken) which 
must have had about 10 whirls in a diameter of '45 ; outside 
nearly smooth, convex ; inside very concave, with the margins 
of the whirls projecting, and beautifully crenated. 
Sab. — Mazatlan ; from shell washings ; L'pool Col. 



Family NERITID^. 
Genus NEEITA, Unn. 
Odontostoma, Klein, non D'Orh., nee TliiL 

326. Neeita scabeicosta, Lam. 

An. s. Vej'f. vol. viii. p. 608, no. 14 — Reel, in Petit Journ. 

Conch, vol. i. pp. 287, 410, pi. 11, f 2.— C. B. Ad. Pan. Shells, 

p. 204, no. 304.— (Non Deless. in Bee.) 
=N. !ornata, Soio. Gen.^X. 4, f. 4. — Wood, lad. Test. Suppl. 

pi. 8, f. 4>.—Rve. Conch. S^sf. pi. 202, f. 4>.—Phil. Ahhild. 

p. 1, pi. 1, f. 2, ^.—Mle. in Zeit.f. Mai. 1850, p. 167, no. 21.— 

Rve. Conch. Ic. pi. 1, f. 3, a, b. 
+ N. Deshavesii, Reel, in Rev. Zool. 1841, p. ISi. — Rve. Conch. 

Ic. pi. 2, f. 7, a, b. 
+ N. multijugis, 3£ke. in Zeit.f. Mai. 1847, p. 179, no. 7, 

(teste Mke. ipso, loc. cit. 1850,)— iSt-e. Elem. Conch, pi. 16, 

f. 86. 
=Pila multijugis + P. ornata + P. scabricosta, S. 8f A. Ad. 

Gen. i. 379, 380. 

The N. ornata of Soto, is referred to the N. scabricosta of 
Lam. on the undoubting authority of Prof Adams. The 
original description (from a supposed unique specimen,) might 
fit many species ; and Desh. (who was debarred by Kien. from 
inspecting the Lamarckian types, even when editing the An. s. 
Vert.) does not venture on synonyms. The N. multijugis of 
Menke, described from adolescent specimens, was abandoned 
by himself, and yet appears in modern works as distinct. The 
form N. Deshaysii, (to which most of the Mazatlan specimens 
belong) is separated in consequence of having more numerous 



356 IIAZATLAN UNIVALVES 

spiral ribs, a taller spire, and a yellow moutli. These charac- 
ters do not always go together, and are each extremely variable, 
as are also the ruga; on the columeUar lip, it being difficult to 
find two specimens exactly alike. The fineness of the ribs 
sometimes differs in different parts of the same shell. The 
colour within presents all shades from a brilliant orange to pure 
white. The sharp labral margin, (crenulated by the ribs,) is 
either black throughout, or tessellated with light between the 
ribs. Spii'e always more or less eroded, even in young speci- 
mens, which in this collection were extremely rare. These are 
known from the next species by the non-granular lip (smooth 
in the youngest specimen,) strong teeth, and raised spire. 
Costa; often scarcely scabrous. Labrum thickly callous within 
the margin, dentate, with very strong teeth at the extremities. 
Rugse often continued on the spire, beyond the flattened colu- 
mella. Operculum (in both the forms N. ornata and N. 
Deshayesii) outside finely granular, with an obscure spiral line 
marking off about a quarter of the shell from the outside, and 
ending in a deep sinus on the inner margin. Tooth stoutly 
projecting, curved downwards opposite the not inconspicuous 
spiral apex. Colour orange brown, A few were found loose, 
with the spiral line scarcely developed, and of a more ashy 
colour. As there was no other large species of Nerita among 
the shells, these are presumed to be of abnormal growth. The 
following shells, selected from but a small stock, exhibit the 
principal variations in the wi'inkling near the second of the 
four teeth : to display- all the minute differences would havo 
been to retain almost every specimen. The shells are not 
nearly so large as further down the coast ; the largest measui*- 
ing only long. I'll, lat. I'lS, div. 110»— 120". 
JTah. — Is. of Timor ; sp. typ. Lara, teste Eecluz. [?] — Eeal 
Llejos, Sowerby. — Panama ; vcrj^ common, on rocks, especi- 
ally in crevices, between high water and three-quarter tide ; 
yotmg crawling above high water mark on rocks and stones 
wet with spray ; C. B. Adama.—S. W. Mexico, P. P. C— 
Mazatlan ; not conunon ; L'pool Sf Havre Coll. 
Tablet 1181 contains 4 sp. of different ages : the smallest, 
"48 across, displays an orange spire, smooth at the apex, with 
distant ribs, intercalary ones appearing at the margin. — 1182, 
1 sp. ribs distant, form ornata.— 11S3, 1 do., ribs changing, in 
part very close, form Deshayesii.— 1184, 2 sp. displaying col- 
oured lip; one with a single orange spot, the other richly 
tinted, inside and out, with spire abnormally elevated. 



Mi-ZATLAX UNIVALVES 257 

Specimens displaying changes of wrinkles. — Tablet 1185 con- 
tains 2 sp. cross-barred, or T-sbaped. — 1180, 3 sp. ciirled round, 
P- or 3-sbaped. — 1187, 2 sp. 7-sbaped.— 1188, 2 sp. obscurely 
F-sbaped. — 1189, 2 sp. V-sJiapf^d.— 1190, 1 sp. :--sbaped.— 
1191, 2 sp. "nrinlilea very sligbtly developed. 

Tablet 1192 contams 3 abnormal opercula. Normal ones axe 
seen with the sbells. 

327. Neeita Bebnhaedi, Be'cl. 

Petit, Journ. Conch. 1850, vol i. p. 285.— .Swe. ConcJi. Ic. pi. 12, 

sp. 57, f. 57, a, h. 
=]Nrerita funiculata. Mke. in Zeit.f. Mai. 1850, p. 169. no. 22, 

(dated "April, 1851.") 
P=Nerita, sp. iud. a, C. B. Ad. Pan. SMh, p. 205, no. 305. 
TbeUostyla Bcrnbardi, M. ^ A. Ad. Gen. i. 380. 

Tbis unpretending, but not inelegant species represents on 
the Pacific coast tbe common W. Indian N. tessellata? from 
wbicb it differs in the more numerous spiral ribs and columellar 
granules, and in tbe irregular style of painting. Shell very 
variable ; with the spire not a little exserted, or quite flat, tbe 
expanded labrum very rarely eVen projecting beyond. Hibs 
more or less numerous, generally scabrous, sometimes nearly 
smooth ; on shells of the same size, they vary from 2 to 5 in 
the tenth of an inch. Coloiu' black, very irregularly spotted 
with a variable number of granules, sometimes large, sometimes 
sraaU : teeth 4, very small and central, sometimes running into 
lines on the lip, sometimes conspicuous, sometimes nearly 
obsolete. Operculum ashy, ver>" finely shagreened outside, 
with a horny layer outside the outer edge, and an inner suius 
nearer the middle than in the last species. Tooth scarcely 
recurved. The largest specimen measures long. '54, laf. '59. 
div. 120"— 180". 
JTah. — Peru, Ciimijtg. — Panama; in extreme profusion, on 

rocks and stones from half -tide level to the low water mark 

of neap-tides ; C. B. Adams.— ^. W. Mexico, P. P. C— 

Mazatlan ; not uncommon ; L'pool Sf Havre Coll. 

Tablet 1193 contains 7 sp. various ages. — 1194, 7 do. shewing 
variations in colour. — 1195, 6 do. varying in height of spire. — 
119G, 6 do. young, shewing variations in sculpture. — 1197, 6 do. 
varying in closeness of ribs.— 1198, 10 do. shewing changes in 
the labial teeth and granulations. — 1199, 6 separate opercula ; 
others being in the shells. 



258 MAZATLAN UNIVALVES 

Gekus NEEITIiS'A, Lam. 
Neritella, Hiomph—B:. S,' A. Ad. Geru vol i. p. 380. 

32S. JNTeeitina cassiculum, Sow. 

Couch. Bl. f, 55.— T/ies. Conch, p. 521. no. 47, pi. 115, f. 194— 

Mi;e. in Zeif.f. Mai. 1850, p. IIG, no. 19.—^. cS" A. Ad. Gen. 

i. 382. 
Comp. N. faba, Sow. Thes. Conch, p. 530, no. 78, pi. 115, f. 219— 

221.— Conch, in. f. 10.— { = Clitlion t H. ^ A. Ad. Gen.i. 

385.) 
Comp. JSTeritina Californica, Rve. Conch. Ic. pi. 4, sp. 20, f. 20, 

a, h. (Gulf of California, Mus. Cuming.) 

^■iltliougli picked specimens may be found so far distinct 
from N. pieta that Messrs. Adams have placed them in differ- 
ent subgenera, individuals may be found in each species so 
nearly alike that it is not impossible that they may ultimately 
prove to be identical.* They display exactly the same varieties 
of form, although they are much more constant in colour. The 
differences observed are as foUo'vs. This species is larger ; 
mouth -^rhite and stained with orange ; inner lip rather flat- 
tened; teeth smaller and more irregular, more resei»bling 
those of N. virginea ; operculum longer, with broader dark 
border, richer orange colour within, and medial line scarcely 
marked. If N. faba does not differ more than is stated in 
Sow.' 3 description, it may prove identical. He characterizes it 
as resembling N. picta, but having "the spire rather more 
hidden, and the columella neither swelled [FswoUen] nop of a 
chesnut colour." It belongs however to another genus, teste 
H. Sf jl. Aa Whether these and connected species in the 
Pacific oe realiy distinct from Iv . virginea with its many-named 
varieties from the Atlantic, it niust be for those to judge who 
have examined large scries from different localities. The form 
exists in the B. il. from China, Philippine Is., and Port Essing 
ton. It is found on the coasts of Spain and reaches Daknatia 
A regularly formed ep. measures long. '68, lat. "83, div. 120". 

A flattened „ „ '57, „ -72, „ 145° 

An elevated „ „ '73, „ '77, „ 90" 

• As such I have freely distributed specimens. It is not unlitely that Prof. 
Adams regarded them as the same. "The specimens which Lieut. Green col 
lected are of extraordinary size." Fan. Skills, p. 207. 



MAZATLAN UNIVALVES 259 

^aS.— (Unknown, Sow.)— Mazatlan, 2Ieii/ce. —Mazailan ; com- 
mon, generally coated \» ith black accretion, similar to that 
adhering to Strigilla carnaria, Terebra albociucta. Area 
tuberculosa, &c. ; Z'pool Col. 

Tablet 1200 contains 2 sp. apex sunken.— 1201, 5 sp-. last 
whirl swollen, apex appearing.— 1202, 5 do. last whirl less 
swollen. — 1203, 5 sp. normal form. — 1204, 6 sp. apex more 
raised.— 1205, 6 sp. still more.— 1206, 3 do. extremely raised, 
mouth veiy slanting. — 1207, 5 sp. violet tinge.— 1208, 5 separate 
opercula ; others being in their shells. 



S29. Neeitina picta. Sow. 

JProc. Zool. Soc. 1832, p. 201. — Desli. in Lam. An. s. Vert. 

vol. viii. p. 588, no. 4D.—Sjiv. Conch. III. no. 35, pi. 86, f. 1 :— 

Thes. Conch, p. 530, pi, IIG, f. 267-9.— Jffo. in Zeit.f. Mai. 

1850, p. 167, no. 2(1— C. B. Ad. Pan. Shells, p. 206, no. 307 — 

R-oe. Conch. Ic. pi. 23, sp. 101, f. 101, a, b. 
Vitta picta, S. Sf A. Ad. Gen. i. 383. 
Oomp. N. Guayaquilensis, D^Orh. Soio. TJies. Conch, p. 520, 

no. 41, pi. lU, f. Vn.—Bce. Conch. Ic. pi. 23, sp. 104, f. 103 

b. (uon a.) 
Comp. N. Fontaineana, B. M. Cat. If Orb. Moll. p. 34, 

no. 305. (Eio da Guayaquil.) 

The variations in this species are extraordinary. Not only 
does it present the changes of colouring recorded below, but 
the form is very inconstant. Sometimes it is nearly globular, 
with the spire not exserted and flattened ; sometimes it is 
much produced. Sometimes the mouth is nearly straight with 
regard to the axis ; sometimes very slanting. Sometimes the 
outer lip is regular, sometimes anteriorly lengthened. The 
brown spot which is supposed to be characteristic of the species 
varies in intensity, and is scarcely seen in very young shells. 
It is not uncommon to find specimens whose apex betokens a 
different painting from that afterwards adopted ; and to find 
shells whose back affords one pattern and the front another. 
The denticulation also of the inner lii> varies in intensity and 
arrangement ; so that it is difhcuit to assign any character, by 
which the whole species may be included and at the same time 
separated from its neighbour.-?. The operculum is grey outside 
with an exterior horny layer, and a ridge near the straight 



Z80 MAZATLAN UXIVALVE3 

edge : within it is yellowish green, with, two orange projecting 
teeth, one conical at the nucleus, the other spiral; with a 
eUghtly raised central spii'al line. The measurements vary 
as in the last species ; one of ordinary growth measures 
long.-b, lat.-Q'i, div. 130". 

Sab. — Panama ; on a mud bank partially overflowed with 
fresh water ; Cuming. — Do. ; on sticks and stones, in a grove 
of trees, a little above half tide level ; also in dirty places on 
rocks at or a little below half tide level ; strictly marine ; 
C. B. Adams. — San Miguel ; of extraordinary size ; Lieut. 
Green. — Mazatlan, Menke.— California [PUpper] Lady Doug- 
lass, B. ]VI. — "Australia ; given by — jMetcalf, Esq."* 
B. M. — ilazatlan ; abundant, sometimes pierced by Grastero- 
pods ; L'pool ^' Havre CoU. 

Ordinary network 2}aftern ; lilac tinge. — Tablet 1209 contains 
12 specimens very close pattern. — 1210, 7 do. close. — 1211, 7 do. 
open. — 1212, 5 do. very open. — Obscurely trifasciate. 1213, 
12 do. very close. — 1211, 12 do. close.— 1215, 8 do. open.— 1216, 
6 do. very open. — 1217, 6 do. colour changing. — Grey tinge. — 
1218, 3 do. extremely light.— 1219, 6 do. with rows of dots. — 
122v0, 5 do. greenish.— 1221, 5 do. spotted suture.— 1222, 7 do. 
darker.— 12 .'3, 3 do. close pattern.— 1224, 5 do. obscurely tri- 
fasciate. — Very dark colour. 1225, 4 sp. grey tinge, very close 
markings. — 1226, 4 do. close.— 1227, 4 do. brown tinge. — 1228, 

4 do. purple tinge. — 1229, 7 do. nearly black. — 1230, 4 do. 
obscurely trifasciate. 

Striped and zigzag pattern.— Tablet 1231 contains 8 sp. inter- 
mediate. — Grey a:id olive green tinge. 1232, 6 do. light. — 1233, 
9 do. with black sutural spots.— 1234, 4 do. grey.— 1235, 9 do, 
olive appearing.— 1236, 5 do. dark striped. — 1237, 7 do. light 
olive, fine streaks. — 1238, 7 do. broader streaks. — 1239, 5 do. 
dark olive, close streaks. — 1240, 5 do. more distant streaks. — 
1241, 3 do. mottled. — 1212, 5 do. grey appearing. — 1243, 4 do. 
very close pattern. — 1214, 4 do. less close. — 1245, 5 do. yellow 
appearing. — Lilac tinge. 1248. 5 do. dark. — 1217, 5 do. light. — 
1248, 7 do. yellow appearing. — Yellow and greenish tinge. 1249, 
6 do. very light.— 1250. 7 do. light.— 1251, 6 do. darker.— 1252, 

5 do. long stripes.— 1253, 2 do. broader. — 1254, 7 do. large 

• Several Mazatlan shells (known by their habit as well as by their species) 
occuring in the B. M. with the above inscription, it is probable that they were 
procured from the lliure Col. which was sold piecemeal at the London auctions, 
vrithoat any assi^ne 1 h:ibitat ; and that Mr. Metcalf erroneously supposed them 
to h&ve come from Australia. 



MAZATLAN T7N1VALVES 261 

sutoral yellow patches. — 1255, 7 do. greener. — 1256, 7 do. dark- 
er. — 1257, 2 do. intermediate. — 1258, 5 do. close grained. — 
1259, 4 do. striped.— 1260, 7 do. obscurely trifasciate.— 1261, 4 
do. dark close pattern, fine lines. — 1262, 5 do. coarser lines. — 
1263, 7 do. mottled pattern. — 1204, 5 do. obscurely trifasciate. — 
Olive green tinge. 1265, 5 do. verj^ liglit. — 1266, 7 do. ratber 
darker.— 1267, 7 do. greyisb tinge.- 1268, 5 do. darker.— 1269, 
7 do. very dark. — 1270, 5 do. closer markings.-«-1271, 8 do. 
obscurely trifasciate. 

Banded variety. Grey tinge. — 1272, 7 sp. close pattern.- — 
1273, 4 do. speckled. — 1274, 6 do. band more developed. — 1275, 
4 do. band coloured. — Lilac tinge. 1276, 9 do. close pattern. — 
1277, 7 do. greenisb band. — 1278, 7 do. variable markings. — 
1279, 5 do. open pattern. — 1280, 9 do. baud margin %vitb broad 
spots. — 1281, 10 do. narrow spots. — 1282, 8 do. with white 
lines. — 1283, 4 do. without white. — Greenish tinge. 1284, 4 do. 
light, streaked. — 1285, 5 do. spotted. — 1286, 4 do. large spots. — 
1287, 3 do. broken markings. — 1288, 5 do. large zigzag pat- 
tern. — 1289, 4 do. band spotted. — Darlc tolour. 1290, 8 do. 
with yellow flames. — 1291, 4 do. fine markings. — 1292, 7 do. 
broken pattern. — 1293, 5 do. very close grains. — 1^94, 7 do. 
very dark. 

With black sutural hand. Spotted. 1295, 3 sp. very liglit. — 
1296, 5 do. blae, open pattern.— 1297, 5 do. grey.— 1298, 4 do. 
close pattern. — 1299, 5 do. dark lilac— 1300, 4 do. dark grev. — 
1301, 4 do. very di&vk.— Striped. 1302, 4 do. very light.— 1303. 
9 do. olive green. — 1301, 8 do. grey. — 1305, 4 do. dark. — Banded, 
1306, 5 do. lUac tinge, speckled.— 1307, 6 do. grey.— 1308, 4 do. 
striped. — 1309, 3 do. lilac and green. 

Tablet 1310, contains 11 sp. shewing variations in form. — 
1311, 18 sp. shewing variations in the mouth. — In all, 607 
specimens, between every two of which there is an appreciable 
difference. The above enumeration gives but a faint idea of 
the variations, fully to display which every specimen must 
have been retained, and to describe which would have filled 
a volume. 

Tablet 1312 contains 30 separate opercxda ; pthers are seen 
in situ. 



263 Mi^ATLAIf UK I VALVES 

i 

Obdeb PECTINIBEAJSrCHIATA. 

SuBOEDEE EOSTEIFEEA. 

Family VAJS^COEIDiE. 

Genus VANICOEO, Quot/ ^ Gaim. 

Vanikoro, Cluoy ^ Gaim., Voy. a prima mami ; (postea Sigaretus 
seu Velutina.)— 6rra7/, Troc. Zool. Soc. 1847, p. 156, no. 256. — 
H. Sf A. Ad. Gen. vol. i. p. 374 

Narica, Reel, in Sagr. Cub. Moll. 1836, teste PJiil. Handh. 
Conch, p. 184. — "M. Eecl. lias the intention to form a genus," 
D'Orh. Cuba, vol. ii. p. 39 : genus constituted, 1844: teste 
Chay. 

Merria, Gray, Zool. Beech. Voy. 1839, p. 137, (anim. descr.) 

Leucotis, Swains. 1840, Treatise, p. 346. 

330. Vanicoeo cetptophila, n. s. 

V. t, parvd, Sigaretoided, temii, albidd ; nucleo anfr. iii. 
quorum primus planatus, alteri suhtnrriti, ienuissime sfriati, 
decliviter sito ; anfr. normalibns ii. rapide augentibus,suhplana- 
Us, irregulariter striulis spiralibus creberrimis et striis incre- 
menti, interdum his, interdum illis super antibus, ienuissime 
cancellatis ; aperturd valde expansd, vix peripiheriarn, penul- 
iimam' attingente ; labro elongato, labio recto ; umhilico maximo ; 
periphcrid angustiore. 

This little creature resembles the Cal.nitra'idEe in its seden- 
tfry habits, frequenting the burrows of worms, &e. in Spondylus 
and Cbama valves, where its flattened form and advanced lip 
(in this respect resembling Trochita) allow it to live in a very 
narrow space. Many specimens were found in situ, but there 
was no trace of operculum. A miniite shell of one whirl (found 
inside the mouth of anothei-,) is perfectly formed, like a tumid 
Planorbis. Another, which was adhering over the umbilicus of 
an adult, is just preparing to commence the normal portion, 
and is shaped like a Bithinia. It then lays its spire sideways, 
but not always at the same angle, and begins a flattened 
Sigaretoid growth. The sculpture is extremely variable, 
sometimes nearly evanescent. Most of the 85 si^ecimens found 
were verj'^ small ; the nuclear shell measures '02 by '016 ; a 
remarkably large specimen measiircs long. '15, lat. "17 by 15. 



MAZATLAN tTNIYALVES 263 

JTai.— Mazatlan ; rare, in worm-eaten passages and burrows 

of Spondylus and Cliama ; L'pool Col. 

Tablet 1313 contains the fry inside an adult, the nuclear 
shell, and 2 sp. in the first stage of normal growth.— 1314, a 
series of 8 sp. of difi"erent ages and patterns. One has ita 
mouth filled with most beautiful spiculiB of sponge.— 1315, a 
sp. in situ in a fragment of Spondylus. 

Family CALYPTEiElD^. 

The genera of this family, united by Lesson, Broderip and 
Beshaijes, though veiy different when adult in their principal 
forms, are so closely related when yoimg that if the fry be 
examined when just emerging from the spiral nucleus it would 
be difficult to say into which genus each sheU would develop. 
The ordinaiy young state of Crucibulum has only half a cup, 
each side being laterally adherent, resembling on the one hand 
the sunken Crepidulsc, as C. adimca, on the other, (supposing 
the half-cup to grow forward separate) Calyptrsea proper, 
(C. equestris, &c.) The amount of lateral adherence, the 
absence of which forms the subgenus Calj'ptrsea a of Brod., 
(C. rudis, _Brof?. = umbrella, Desk.) varies in specimens of the 
same species. The internal lamina, more or less spread out or 
lobed in species of Crepidula, with the margins- doubled 
together forming a cup in Crucibulum, is in Galerus , very 
slightly turned over and flattened, these characters varying in 
the species. Trochita is simply an extreme of Galerus on the 
one hand, or of the spiral Crepidula? on the other. For par- 
ticulars of the generic svnomyms, v. Gray's Synopsis in Proc. 
Zool. Soc. 1847, p. 157 ; R. Sf A. Ad. Gen. vol. i. p. 363 ; Phil. 
Handb. Conch, p. 186. For particidars of species, v. Srod. in 
Proc. Zool. Soc. 1834, p. 35 ; id. Trans. Zool. Soc. ; Desk. in. 
Lam. An. s. Vert. vol. vii. p. 619 ; C. B. Ad. Pan. Shells, 
p. 219 ; B. M. Cat. B'Orh. Moll. p. 47. Menke'a species, given 
in Zeit. f. Mai. 1846 — 1851, are not described with sufficient 
accuracy to allow of certain allocation. They seem often 
named from worn and young specimens, and would probably 
have received great revision, had the author examined a large 
series of specimens like the present. As ho is describing 
Mazatlan and not New Zealand shells (as his names would 
sometimes imply), his species are here allotted acording to 
the prerponderance of characters. The foUowing genera are 



264 MAZATLAN ITKITALYES 

adopted from tlieir great convenience. Of Calyptrsea proper, 
which is the best marked in its characters and is well repre- 
sented both in individuals and species in the Caribbsean and 
equatorial West American Seas, only a single individual waa 
found in the entire Mazatlan collection. None of the species 
were found with a solid shelly attachment, though a thin 
deposit may sometimes perhaps be traced. In general a cavity 
is excavated on the backs of other shells. 



Family CALYPTE^IDiE. 
G-E^vs TEO CHITA, Schnm. 

Schnm. Ess. no. 11, ISlh— Gray, Froc. Zool. Soc. 1847, p. 158, 

no. 272— Phil. Eandb. Conch, p. 187.— J. ^ A. Ad. Gen. i. 

867. 
Trochus, pars. Lam. — Calyptra;a, pars. Desk. Sigapatella, Lest, 

1829, Toy. Ccxj.— Trochatella, Less. 1830, (teste Gray.)— hi- 

fundibulum, D'Orb. 1846, non Moiiff. 

This genus foi'ms an exact transition in the shell from the 
spiral Crepidula) to the Phorida-, the animal of .'which is 
widely different. It is in fact a Crepidula, with the anterior 
part shortened, while the posterior is lengthened. Several 
species might be ranked with either genus. It is represented 
in the Mazatlan collection by a single specimen. 

331. Teochita tenteicosa, n. s. 

T. t. ventricosa, suhdepressA, irrcgulari ; alhidd, castaneo 
tmbutd ; anfractlbus iii. [^? aut 2^liif'ibus~\ ventricosis, maxiine 
jyrope sutiiram ad ang. 90" depressam ; stiperjicie irrcgulariter 
noduloso-rugosd, rugis subobsoleiis. diagonalibus, iwdulis hue et 
illiic prcrpe suturam extanfibus ; totCi paglnd creberrime et 
minutdssime corrugatd ; epidennide lamellosd, corned, maxime 
propeviarginem, indtitd ; cavifate concavo ; lamina albd, lineaa 
incrementi hand monstranti, labioparum reflexo, umbiliconullo; 
margineform(C sedis convenienfe. 

Corap. Trochita radians, (Desh. teste IT. ^ A. Ad. Gen. i. 367,) 
D/fcr. Lnd. Moll. Guin. p. 36, no. 97:=Trochu3 r. Lam. An. 
s. Vert. (ed. I.) vol. vii. p. 11, no. 5 : — Schtib. ^" Wagn. 
Chemn. Snppl. pi. 2^9, f. 4063 :— = Calyptja^a r. Zam. ed. 
Desh. vol. vii. p. 620, no. 8 : — = luf undibulum r. Zool. Peech. 
Voy. p. 1'18, pi. 39, f. iO, 11 :—= Patella trochiformis, Chemn. 



MAZATLAN TKIVALVES 265 

vol. X. pi. 168, f. 1626— 7 —DiUw. Bee. Shells, p. 1018, 
no. 6:— = Calyptrfea (Trochatella) t. B. M. Cat. D'Orb. 
Moll. p. 48, no 411 :— + Patella trochoides, DUhv. loc. cit. no. 
7: — +Calyptrfea Arancana, Less, (teste D'Orh. Cat.) — 
?Jun. = Calyptrtta dilatata, Soto. Gen. f. 9, (non Crepidiila 
d., f. 5.) — Calyptra^a radians, (max.) Val. Voy. Ven. pi. 14, 
f.^; pi. 15, f. 4. 

Of this beautiful species, besides the specimen liere des- 
cribed, I have seen only one other, in the collection of T. 
NuttaU, Esq., from an unknown locality. It differs from the 
S. American T. radians, (also quoted from Benguela and St. 
Vincent, Guinea, on the authority of Br. Tarns ; and of which 
a remarkably conical variety is figured in Beechey's Voyage ;) 
and also from the G-idf species, T. spirata, in the great con- 
vexity of the whirls, which are so produced at the shoulder 
that the sides of the sutiire form nearly a right angle. It ap- 
proaches most nearly to a fossil species from Dax, which 
however has the base still more concave. The Infundibulum 
Californicum, H. Ad., (Proc. Zool. Soc. 1851, p. 153,) which 
from its name might be supposed to have some connection, is 
a species of Polydonta, (Trochinae.) Diam. '74, alt. '64, (cuius 
anf. xdt. -48,) div. 110". 

JIab. — Mazatlan ; one fresh sp. ; L'pool Col. 
Tablet 1316 contains the specimen. 

Genus GALEEUS, Gra?/. 

Galenis, Humph. 1797 -.—Gray, Proc. Zool. Soc. 1847, p. 157, 

no. 269 i—Phil. Ilandh. Conch, p. 187 -.—S. ^' A. Ad. Gen. 

vol. i. p. 367. 
Trocliita (pars,) Schum. 1817.— Calyptr£ea (pars,) Lam. 1822.— 

Sii)liopateLla (pars,) Brod. 1834. — Infimdibulum, pars, J. 

Sow. — Trochatella, pars, B'Orb. 
Mitrula, Gray, 1821.— Trocliilea, Swai?is. 1837. 

This genus is intermediate between Crepidulaor Crucibulum, 
and Trochita. The shell is conical, slightly spiral, with a 
rapidly ascending spiral lamina, doubled in upon itself. Unfor- 
tunately, no very young shells were found of this section. The 
plane of the vertex is parallel to the base in aU observed species. 

332. Galeefs coNictJS, Brod. 

Calyptraia (SiphopateUa) conica, Brod. Proc. Zool. Soc. 1834, 
p. 38 -.—Trans. Zool. Soc. vol. i. p. 202, pi. 27, f. 7.— Mull. 
July 1856. g 



266 MAEATLAN UNIVAlVES 

Si/n. Noo. Test. Viv. p. 147.— (Calyptrsea c.) Lavi. An. s. Vert. 

vol. vii. p. 630, no. 17. — C. B. Ad. Pan. Shelh, p. 220, 

no. 333.— rC. Trocliatella c.) Mke. Zeit. f. Mai. 1851, p. 3r.. 

no. 126.— (Galenis c.) H. Sf A. Ad. Gen. i. 368. 

Tlie nuclear vertex in this species is generally eroded ; but, 
when perfect, resembles that of G. Sinensis, about '02 across, 
not promiuent, with the outer wliii-l enveloping the rest, apex 
not visible. The colour is of a beautiful pinkish brown, 
lustrous, uniform over the shell, and variously stained or spot- 
ted. The lamina makes a rapid ascent to the margin, is much 
flattened, with the inner edge elegantly rounded, recurved 
over from 3-4ths to 4-5ths of its breadth, and a third part of 
its length. The recurved part is open, but not swollen within. 
Long. 1-27, lat. Vii, alt. -66. 
Hah. — Xipixai)i and Salango, attached to shells in deep water, 

Cuming. — Panama, verj- rare, C. B. Adams. — S. W. Mexico, 

P. P, C. — Mazatlan ; extremely rare ; L'pool Col. 

Tablet 1317 contains 4 sp. of which the youngest is "08 across, 
and the next is coloured as in C. lichen, Brod. 



333. Galeeits mamillaeis, Brod. 

Calyptrspa (Siphopatella) mamUlaris, Proc. Zool. Soe. 1834, 
p". 38 -.—Trans. Zool. Soc. vol. i. p. 201, pi. 28, f. 5.— (Calj-p- 
traa m.) Lam. An. s. Vert. vol. vii. i). 631, no. 18. — (Galeru.<? 
m.) n. Sf A. Ad. Gen. i. 368.— (Non C. TA)chatellam. B. M. 
Cat. UOrh. Moll. p. 48, no. 412.) 
+ Calvptrsa regularis, C. B. Ad. Pan. Shells, p. 224, no. 340 :— 

id. ip. 320.— (Galerus r.) H. ^ A. Ad. Gen. i. 368. 
= Calyptrffa (Troohatella) Lamarckii, Mke. Zeit. f. Mai. 1847, 
p. 180, no. 37:— id. 1851, p. 36, no. 125.— (Non Desh. Lam. 
An. s. Vert., vol. vii. p. 627. no. 9.) 
? + Calyptnf a (Siphopatella) Lichen, Brod. Proc. Zool. Soc. 
1834, p. 37 -.—Tran^. Zool. Soc. vol. i. p. 201, pi. 28, f. 4.— 
(Calyptnea 1.) Jjam. An. s. Vert. vol. vii. p. 630, no. 16. — 
(Galerusl.) H. SfA.Ad.l 368.-(Teste B. M. Cat. B'Orb. 
Moll. p. 48, no. 412, = "lorica" err. typ.) 
The specimens of G. mamillaris in the Cumingian coIlec<ion 
vary greatly in colour and sculpture. Some of these, as well 
as G. lichen, closely resemble the young of G. conica. A 
microscopic examination of the nuclear vertices would pro- 
bably decide the question. The vertex of G. mamillaris is 



MAZATLAN UNIVALVES 267 

about "02 across, generally rather separated from the shell, 
and of an elegant discoidal shape like Planorbis, displaying the 
whirls and the sunken apex. The whirls increase rapidly and 
regularly, sometimes developing concentric wrinkles (as in 
Crep. nivea,) just beyond the nuclear portion. The internal 
lamina makes a more complete revolution than in G. conica ; 
the central margin is more produced, and the reflection is only 
over half the breadth. The Mazatlan shells differ from G. 
Sinensis and its W. Indian congener, in the reflection of the 
lip, which is nowhere closed, in the character of the nucleus, 
and in the non-spinous surface.* The coloiir is often of a rich 
brown within and near the vertex ; otherwise of a dingy white. 
Epidermis very thin. The cone is more or less depressed. 
The form G. lichen is probably only a flattened variety of this 
species ; but may be distinct. The C. mamillaris of D'Orb. is 
the C. u.nguis of Brod. and appears a distinct species, of which 
the C. sordida of Brod. is probably a variety : the lamina being 
so much reflexed as to pass into Crucibulum, the young of which 
however it does not at all resemble. The ordinary size of G. 
mamillaris is as in G-. Sinensis ; an extraordinarily large one 
measures long. 1'26, lat. 1'23, alt. "56. 

Hab. — Isl. Muerte; on dead shells, sandy mud, 11 fm. ; Cum- 
ing. — (Gr. lichen.) Idem, Cuming. — (G. regularis) Panama ; 
extremely rare ; C. B. Adams. — Acapulco, Col. Jeivett. — 
Sta. Barbara, Col. Jewett. — Mazatlan ; not uncommon, ad- 
hering to shells, and to each other ; L'pool Col. — Payta to 
Guayaquil, D'Orhigny. 

Tablet 1318 contains 6 pale specimens. — 1319, 6 do. dark 
colour, (one in situ.) — 1320, the largest specimen. 

Genus CEEPIDULA, Lam, 

Crepidida, Lam. 1799.— Phil. Sandh. Conch, p. 188. 
Sandalium, Schvm. 1817. 

Cr>T)ta {Humph. 1797) Grai^, 1847 : S. ^^ A. Ad. Gen. vol. i. 
p. 368. 

The species of this genus run into each other in the most 
marvelous manner. The characters even of the young sheU 

• The AV. Indian analogue of this species is CaljptrsBa liBvigata, Lam. : r. 
Deless. liec. Coq. Lam. pi. 25, f. 3 a, b, c. The C. extinctorium, Lam. (quoted by 
Sow. for a totally different shell) appears from the same work, he. cif. f. 2, a, b, 
c. to be a somewhat similar, blackish Galerus, in which howe\cr tho outside and 
the inside representations of the spiral element do not agree. 



268 MAZATLAN ITNIVALVE8 

are often by no means constant. It has been tbe object, in 
the following selection from the multitudes of individuals in the 
Mazatlan collection, to illustrate the variations of which each 
species is siisceptible.* 

334. Ceepidula aculeata, G^mel. 

Patella aculeata, Gmel. p. ZQm—Bilhv. Dcsc. Cat. p. 1020, 

no. 11. 
Patella fornicata aculeata, Chemn. Conch. Cah. vol. x., p. 334, 

pi. 168, f. 1624-5. 
Patella fornicata, var. Schreih. Conch, vol. i. j). 338. 
La Eetorte epineuse, Favanne, vol. i. p. 564, pi. 4, f. F. 2. 
CrepidiJa aculeata. Lam. An. s. Vert. vol. vii. p. 642, no. 3. — 

Desk. Enc. Meih. Vers, vol. ii. p. 27, no. 11. — Sow. Gen. 

f. 4,.—B. M. Cat. Cuba Moll. p. 33, no. 395.-5. M. Cat. 

D'Orb. Moll. p. 48, no. 4lo.— ?? Brod. bx Proc. Zool. Soc. 

1834, p. d9— Gould, ms. Cat. Cat. Shells.— Bkr. Ind. Moll. 

G-vAn. no. 94. — Kraiiss Sudafr. Moll. p. 69, no. 4. 
Crepipatella aculeata, H. Sf A. Ad. Gen. i. 369. 
+ Crepidula Capensis, B.M.: {?=Quoy Sj' Gaim. Voy. Astr. 

vol. iii. p. 424, pi. 72, f. 13,14; — Lam. An. s. Vert. vol. vii. 

p. 645, no. 9 : — Krauss, Sudafr. Moll. p. 68, no. 1.) 
+ Cal.yptra>a (Crepipatella) echinus, Brod. in Broc. Zool. Soc. 

1834 p. S9.—T)-ans. Zool. Soc. vol. i. p. 203, pi. 27, f. I.— Mull. 

S:/n. Nov. Test. Viv. p. 148.— jff". cf" A. Ad. Gen. i. p. 369.— 

(Crepidula e.) Lam. An. s. Vert. vol. vii. p. 650. no. 23. — 

C. B. Ad. Pan. Shells, p. 226, no. 344. 
+ Calyptra;a (Crepipatella) hvstrix, Brod. Proc, Zool. Soc. 

1834, 1^.39:— Trans. Zool. Soc. vol. i. p. 203, pi. 29, f. 2.— 

H. ^- A. Ad. Gen. i. p. 369.— (Crepidida h.) Lam. An. s. Vert, 

vol. vii. p. ft50, no. 22. 
+ Crepidula costata, Mke. in Zeif.f. Mai. 1847, p. 183, no. 32 : 

(non Sow. nee Quo//, nee L>esh. in Lam. An. s. Vert. vol. vii. 

p. 644, no. 7.)— Id. 1^51, p. 35, no. 122. 
+ Crepidula Californica, JVutt. ms. in Warrington Mus. 

* I have been compelled to unite several species usually regarded as reiy dis- 
tinct. On shewinc a series to an author deservedly distinguislied, proving that 
lour species were identical which he had grouped under two subgenera, he com- 
plained that I had kept all tho puzzling shells ! It is easy, as one naturalist is 
recorded to have done, to smash all specimens not according with our classifica- 
tion; eras another, to pick out all the leading forms and describe them as 
distinct species, genera, or even orders, disregarding the intermediate ones which 
would have proved them identical ; but the interests of science are not served by 
either one course or tho other. Our object must ever be, not to make Nature 
speak our language, but to find out what is the language of Ifature, 



MAZATLAK UNIVALVES 269 

My attempts to find specific diiFerences between the Atlantic 
and Pacific shells have entirely failed. The former are generally 
of a more reddish, the latter of a browner cast ; but those 
from Chili belong to the Atlantic type ; while those from 
Honduras go through the same changes as the Mazatlan shells. 
The Patagonian shells may belong to either type. The C. 
echinus of Brod. represents the form in which all the ribs are 
equal and very spiny ; the C. hystris that in which a few are 
developed, with large spines, at the expense of the rest. The 
two forms run into one another, and into the common form, 
almost imperceptibly. In first describing them, JBrod. candidly 
states that he would not be positive that they are not all varie- 
ties of C. aculeata. There is a distinct variety which bears 
the same relation to the typical form that C. squama does to 
C. nivea. It is flat, very regidar, without spines, but covered 
with extremelj' crowded imbricated scales. The Californian 
variety is the most aberrant, being small, nearly round, and 
never spiny. It might pass for a distinct species, were it not 
that a few of Mr. Nuttall's specimens exactly belong to the 
Mazatlan type, while some few of the degenerated Mazatlan 
specimens are closely allied to those from Monterey. — The 
young shells which Menke obtained from coral on Spondylus. 
Chama, and Murex nigritus, and affiliated to the jS'ew Zealand 
form, (so well marked that it received the same name from three 
distinct sources), appears from the diagnosis to belong to this 
species. 

C. aculeata belongs to the group of regular^ spiral Cre- 
pidulse. It begins life as a smooth, glossy, light horn-coloured, 
Velutina-shaped shell, with rapidly increasing whirls, and 
a sunken apex. This is much larger than the nuclear part of 
C. nivea, though the adult shell is much smaller ; being about 
'025 across when it begins its second stage. C. nivea begins 
with concentric ridges and goes on smooth, rapidly increasing, 
but in a regular curve. C. aculeata makes a sudden expansion 
when forming its deck, and then develops ridges as in the 
form C. Lessonii. These soon become more or less undulated, 
and then assume the state of vaulted spines, diff"ering in size 
and arrangement, and in the period at which they commence. 
At the same time various rays or spots of chesnuf colour 
appear. Within, tlie growth of this species offers a well 
marked contrast to that of C. nivea and its congeners. Instead 
of forming a basal columella lip and then throwing up a deck 
at a considerable angle, this shell makes the columella Hp the 



270 MAZATIAN UNIVALVES 

commencement of its deck, which, it continues from it in a 
regular curve. The marginal lip also is very short, not cover- 
ing the spire as in C. nivea, &e., bnt leaving it for a long time 
very conspicuous. The shell in its early decked stage has 
much the appearance of a Keritina. The deck however is 
extremely thin, alwaj'S displaying stria) of growth. It soon 
develops a central sinus, leaving the margin arcuated, not 
angidated. From this regular spiral growth, the transition is 
easy, through other species, to the form Trochita. The adult 
shell has normally a deck margin of the form r»Ok^^, one side 
of the brace being longer than the other. The point develops 
a spiral line to the apex. Sometimes however this point is 
rounded ; each sinus and lobe may be developed at the expense 
of the rest ; and in one specimen, the outer lobe being pointed 
while the middle point is rounded, the margin assumes the 
form of an irregular inverted brace ^-^'Y'nj. The ordinary 
colour id a yellowish white variously striped, spotted or mottled 
with lustrous chesnut or dark brown. Karely the whole shell 
is dark brown, most rarely piu'e white. The red tints observ- 
able in the Chili and Atlantic specimens have not been found in 
the Gulf district : they are not mentioned however in Dillwyn's 
description, and perhaps are due to the fading of the brown, 
most of the W. Indian specimens in collections being dead. 
Those brought by Mr. D. Dyson from Honduras are coloured 
like the Mazatlan specimens. The external markings, on 
which Brod.'s species are founded, are extremely variable. 
"Well developed specimens of hystrix and echinus are rare : 
but intermediate forms between these and the common state 
with irregular crowded small vaidtcd spines, arc abundant. 
The W. Indian specimens moreover go through the same 
changes of sculpture. The delicately grown shells, which are 
flatter and broader in proportion, are rough to the touch, but 
the spines are scarcely discernible without a glass. On coarse- 
ly grown shells, they are often not developed over part of the 
surface. The amount of spiral involution varies considerably 
in different specimens. (Comp. C. Cal.ATJtraiiformis, Desk, in 
Lam. An. s. Vert. vol. vii. p. Gi7, no. 15.) The smallest 



specimen is '03 in length. 






The largest sp. measures long. 173, lot. 1"06, 


alt. 


•41 


A convex sp. „ „ 1"12, „ '87, 


)> 


•46 


Aflatsp. „ „ _1-1, „ I', 


,, 


•26 


An elongated sp. „ '8, „ '41, 


,, 


•19 


A convolute sp., apex tu front '68, io hack 


•33. 




A straight sp. , "92, „ 


•18. 





MAZATLAN UNIVALVES 



271 



A loug decked sp., margin to front *36, to back '47. 
A short do. ,, '48, „ *3. 

Sab.~(G. aculeata) W. Indies, passim, auct.—Cnhsi, Sagra.— 
Hondiiras, Dyson. — Brazils: Patagonia; IfOrhigny. — Ben- 
guela ; 1 sp. in excellent preservation ; Tarns. — Table Bay, 
Krauss.—Ga-^e Natal, Mus. Cuming.— Isle pf France, Fav- 
a?me.— Knracliee, Mouth of the Indus, Mus. Cuming.— Port 
Jackson, Bev. R. L. King.—^ew Zealand, Bev. B. Tar/lor.— 
Sydney and Swan Eiver, Mus. Cuming.— (Dark var.) Japan, 
Mus. Cuming.— (Light var.) Chili, Capt. Ld. Byron. — (C. 
echinus, &c.) Lobos Is. Pervi, Cuming. — Panama; under stones 
at low water, rare ; C. B. Adams.— {C. Californica) Monterey, 
common, Nuttall. — Mazatlan ; common, on shells &e. ; 
young shells abundant on Chamaj and Spondyli ; L'pool Col. 
Tablet 1321 contains 10 sp. extremely young.— 1322, 7 do. a 
stage older, with a fragment to shew the inner surface of the 
deck.— 1323, a young deformed shell, nearly smooth, probably 
belonging to this species. 

Specimens illustrating foi'm and sculpture. — Tablet 1324 con- 
tains 8 sp. {var. hystrix) of different ages. — 1325, 13 sp. do. 
(var. echinus.)— 1326, 8 sp. do. finely aculeate, arched.— 1327, 
10 sp. do. flat, (one of the young in situ on an adult.) — 1328, 8 
sp. do. spiny processes 'imperfectly developed. — 1329, 4 sp. do. 
{var. Californica.)— 1330, a series of 12 sp. shewing gradations 
between the above forms. — 1331, 7 sp. shewing gradations from 
flat to arched. — 1332, 6 sp. shewing gradations in amount of 
spiral involution.— 1333, 5 sp. shewing gradations in size of 
deck. — 1334, 6 sp. shewing gradations in prominence or sinking 
of deck. 

Specimens shewing shape ofdecTc. — Tablet 1335 contains 3 sp. 
center i:)ointed, sides much swollen. — 1336, 4 do. sides swoUen. 
— 1337, 3 do. sides slightly swoUen. — 1338, 3 do. center 
rounded. — 1339, 1 do. point tiu'ned outwards. — 1340, 4 do. form 
approaching C. nivea. — 1341, 3 do. deck partially opaque. 

Specimens displaying changes of colour. — Tablet 1342 contains 
2 sp. (hystrix and echinus) pure white. — 1343, 10 sp. variously 
shading into brown. — 1344, 11 sp. do. dark lustrous brown. — 
1345, 12 sp. tortoiseshell, variovisly mottled. — 1346, 5 do. whiter 
tint. — 1347, 6 do. more or less tinged with green. 

Distorted specimens. — Tablet 1348 contains 7 sp. of irregular 
shape. — 1349, 7 sp. diseased by worms. — 1350, 3 sp. with addi- 
tional margin. — 1351. 4 sp. passing towards C. nivea. — 1352, 3 
sp. passing towards C. onyx. 



272 MAZATLAN TJNIVAIVBS 

335. Cbepidula dilatata, Lam. 
An. s. Vert. vol. vii< p. &ii, no. 5. — Deles. Bee. Coq, Lam. pi. 

25, f. 4>, a, b, c— Sow. Gen. f. o,jwn.—B. M. Cat. jyOrh. 

Moll. p. 49, no. 418.— Var. Brod. Proc. Zool. Soc. 1834, p. 

38 :— Trans. Zool. Soc. vol. i. p. 203, no. 21, pi. 28, f. 11.— 

(Crepipatella d.) B:. Sf A. Ad. Gen. i. 369. 
+ Crepidula depressa, Desh. Enc. Metli. Vers, vol ii. p. 26, 

no. 5. (? teste Desh.) 
+ Crepidula Peruviana, Lam. An. s. Vert. vol. vii. p. 49, no. 6.— 

Deles. Rec. Coq. Lam. pi. 25, f. 5, a. b. c.—Dkr. Ltd. Moll. 

Guin. p. 35, no. 95.— (Crypta P.) H. Sf A. Ad. Gen. i. 369. 
+ Crepidula patula, Desh. Enc. Meth. Vers, vol. ii. p. 27, no. 9.— 

Lam. An. .?. Vert. vol. \\i. p. &i6, no. 13.— (Crypta p.) H. Sf A. 

Ad. Gen. i. 369. 
= Crepidula Adolphei, Less. Voy. Coq. Zool. vol. ii. pi. 15, 

f. 2, 2A. anim. revers.— (Crepipatella A.) S. Sr A. Ad. Gen. 

i. 369. 
+ Crepidula jSTautiloides, Less, (teste D'Orb. Cat.) 
+ Calyptra'a (Crepipatella) strigata, Brod. Proc. Zool. Soc. 

1834, p. 39 -.—Trans. Zool. Soc. vol. i. p. 203, pi. 28, f. 12. 

Zool. Beech. Voy. p. 148, pi. 39, f. 13.— (Crepidula s.) Lam. 

An. s. Vert. vol. vii. p. 651, no. 24.— Crepipatella s.) K. Sf A. 
^ Ad. Gen. i. 369. (teste D'Orh. Cat. : PPteste Brod. ipse.) 
?? + Calj-ptra^a (Crepipatella) pallida, Brod. Proc. Zool. Soc. 

1834, p. 39 -.—Trans. Zool. Soc. vol. i. p. 204, pi. 29, f. 3.— 

(Crepidula p.) Lam. An. s. Vert. vol. vii. p. 650, no. 21.— 

Crepipatella p. H. Sf A. Ad. Gen. i. 269. (teste D'Orh. Cat.) 
+ Crepidula arcuata, DOrb. [quasi jB;'oc/.] B. M. Cat. Moll. 

p. 49, no. 420. (teste Gray.) 
? + Calyptrrea (Crepipatella) foliaoea, Brod. loc. cit. pi. 28. f. 9.— 

B. M. Cat. D'Orb. Moll. p. 19, no. 419. (Pteste Gray.) 
? + Crepidula Patagonica, D'Orb. B. M. Cat. p. 48. no. 416, 

(Pteste Gray.) 
Comp. Crepidula lineolata, Desh. in Lam. An. s. Vert. vol. vii. 

p. 616, no. 11. 

To this formidable list of synonyms. Dr. Gray adds C. protea 
o{ D'Orb. and DOrbigny adds C. unguiforniis, Brod. These 
skells appear however more nearly related to C. nivea, C. B. Ad. 
and C. unguiformis, Lam., to which last, the West Indian 
specimens of C. protea (B. M. Cat. Cub. Moll. p. 33. no. 396) 
probably belong. Some of the specimens marked C. protea 
by DOrb. are perhaps dead shells of C. onyx. It wiU be 
observed that this species is distributed under two subgenera 



MA25i.TLAN UNIVALTfiS 273 

by Messrs. Adams. No specific difference can be traced be- 
tween tlie Sandwich. Island specimens, tliose from Mauritius, 
and the abundant forms from S. America. The species does 
not affect the Northern hemisphere. It is not quoted by 
C. B. Adams in his Panama list. The solitary specimens from 
Gruinea, Mazatlan and California may hare been imported. Of 
the two Lamarckian names, the first is chosen, although very 
imperfectly described from a single specimen in the collection 
of Mde. de Bandevill^, because it well expresses the usual 
character of the species, and has been adopted by D'Orbignv. 
Long. 1-42, led. 1-2, alt. "68. 

Hab. — S.America, D'Orhigny. — Mazatlan; 2 large but dead 
specimens ; L'i^ool Col. — Lower California; 1 dead specimen ; 
Major Rich. — (C. Peruviana.) Peru, Dombey. — Peru and 
Chiloe, Bern. PhiUpin. — (1 sp.) Loander, Tarns. — (C. patula) 
Otaheiti, Lesson. — (C. strigata.) Valparaiso ; on Mytdi, 
3 — 6fm. ; Ciiminq. — (C. pallida.) Falkland Is. ; under stones ; 
Cuming. — (C. arcuata.) Payta, Peru, D'Orbigny. — (C. lineo- 
lata.) South Seas, Deshayes. 

Tablet 1353 contains a specimen, with attachments of two 
others on its back. 



336. Ceepidtjla Pdoesata, Brod., var. bilobata. 

C. t. tenui, subcirculari, suhdiaphana, alhidu, scepe fusco 
radiatd seic maculata ; ve^'tice nucleoso globoso, satis magno, 
apice subdepresso, anfractibus rapide augentibus, vix extante, 
hand prominente, a margine valde remoto ; Icevi, seu striis inn'e- 
menti, inter dum lamelUs irregularibus ; hue et illuc vix radiatim 
striata, seu propter sedem quasi costatd ; lamind tcnui, bilobata, 
lobd posteriori parvd, anteriori maximd, ad extremitates sinu- 
aid, apicem versus impressd, incrementi lineas monstrante. 
Calyptrsea dorsata, Brod. Proc. Zool. Soc. 1834, p. 38 : — Trans. 

Zool. Soc. vol. i. p. 202, no. 20, pi. 28, f. 10. 

About a dozen young specimens of this species were found 
in the shell washings ; but some boautifid ? adult shells are in 
Mr. Cuming's Col. The form is intermediate between Crepidula 
and Crucibuliim, the young state of which it gi'catly resembles. 
The lamina is attached by less than one half of its total 
length ; and the vertex is situated about half waj' up the 
height of the shell. The above diagnosis was written in ignor- 
iance of Brodcrip's species, which (with others) had been lost 



274 MAZATLAN UNIVALVES 

in Mr, Cuming's Museum, but wluch. lie has allowed mc to 
restore from the overwrought figures in the Transactions. It 
is closely related to some forms of C. dilatata, jun. 

The mode of growth in the young shell is as in C. nivea, &c. 
The vertex is rather large, "02 in. or upwards across, Velutina- 
shaped, smooth, with a rather sunken apex and rapidly increas- 
ing whirls. On commencing the permanent form, it spreads a 
film over the base of the spire and a very large margin all 
round. The deck commences at a considerable angle from this 
film, first as a marginal line, then gradually developing tUl the 
lobes are formed. The vertex is rather prominent, but not 
separate from the body of the shell. Some of the shells are 
more solid than Mr. Cuming's adult specimens ; and further 
agree with the typical C. dorsata in being of a yellowish cast, 
with the deck rather brown. The subdiaphanous white 
specimens are sometimes spotted with chesnut. The largest 
Mazatlau specimen, (the margin of which is dentated) mea- 
sures . . long. "33, lat. "37, alt. '12. 
Mr. Cuming's sp. . „ "6, „ '56, ,, "27. 
jHaft.— (C. dorsata.) St. Elena ; on dead shells, in sandy mud, 
6 fm. ; Cuming, (teste Brod. :— Valparaiso, teste Mus. Cum.)— 
(Var. bilobata.) California ; Mus. Cimiing.— Mazatlan ; ex- 
tremely rare, jun., on shells ; L'pool Col. 
Tablet 1354 contains 5 sp. of difierent ages. In the first, "03 
across, the margin is formed, but not the deck : in the second, 
the deck line has commenced. 

337. Ceepidula excavata, Jirod. 

C. t. tenuiore, lann, ohlongd, latere dextro expanso, sinistra 
convexo ; alba, castaneo varie maciclatd, Infus nitente ; vertice 
valde adunco, a margine maocime separato, dextrorsum valde 
spiraliter contorto ; niicleo satis magna, discoidali, satis iiijlato, 
apicem depressmn monstrantc, regulariter crescente ; habitu, 
incrementi siibspirali, abliquo, regulari ; septo tenuiori, vix 
opaco, ad marginem tineas incrementi monsfrante, vix in medio ; 
hand aliter simiata ; oblique et profnnde sito, cavitate magna 
adverticeili ascendente ; Vnnho acuta. 
Calyptraa (Crepidida) e. Brod. in Proc. Zool. Sac. 1831, p. 46 :— 

Trans. Zool. Sac. vol. i. p. 205, no. 29, pi. 29, f. I.—Miill. Syn. 

Nov. Test. Viv. p. 150. 
Crepid\ila e. Desh. in Lam. An. s. Vert. vol. vii. p. 649, no. 19. — 

C. B. Ad. Pan. SMls, p. 22G, no. 345. 



MAZATIiAN UNIVALVES 275 

This beautiful and rare species combines tbe form and habit 
of growth of the Atlantic C. porceUana, Linn, with the very 
remote apex of C. adunca. This character also separates it from 
C. arenata, Brod. (found at S. W. Mexico, P. P. C, but not at 
Mazatlan,) to some forms of which it bears a close resemblance. 
C. arenata occasionally develops an apical hole within, (Mus. 
Cum.) : but is never seen with the very oblique growth of this 
species. The nucleus is like a regular, somewhat tumid Plan- 
orbis ; shewing the whu'ls within, and measuring about '02 in. 
across. The enlargement is regular, and the young shell has 
exactly the characters of the adult, except that the apex, though 
separate, is nearer the margin. Only two very young specimens 
and one adolescent were found in the Mazatlan collection ; a 
larger one, probably from the same collection, was obtained 
from a shop : and some very fine ones are in the Cumingian 
Museum. The smallest specimen is * 12 in length : the largest 
long. '95, lat. '64, alt. '35. 

^a5.*— Eeal Llejos, Cuming, teste Broderip : (but Grulf of Cali- 
fornia, teste Mus. Cum.) — Panama, 1 sp. C. B. Adams. — 
Mazatlan ; extremely rare, jun. on Spondylus ; L'pool Col. 
Tablet 1355 contains a young sp. — 1356, an adolescent sp. 



338. Ceepidula adunca. Sow. 

Tank. Cat. no. 828, App. p. vii. — (Crypta a.) S. Sc A. Ad. Gen. 

i. 369. 
= Crepidula solida. Hinds, Voi/. Sulph. Moll. p. 53, no. 218, 

pi. 16, f. 7, 8.— (Crypta s.) S. 6f A. Ad. Gen. i. 369. 
= Crepidula rostriformis, Gould, Exp. Shells, 1846. p. 14. 
Jun. = Crepidula rostrata, C. B. Ad. Pan. Shells, \>^. 235, 

320, no. 353.— (Cr^i)ta r.) H. Sf A. Ad. Gen. i. 369. 
Jun. var. = Crepidula uncata, Mke. in Zeit.f. Mai. 1847, p. 184, 

no. 34. 
= Crepidula incurva, var. P. P. C. Cat. Prov. 
Garnotia solida. Gray, Gen. 3Ioll. B. M. p. 117. 

The very remarkable form of this species has attracted the 
attention of six celebrated uatm-alists, each of whom have im- 
posed upon it a separate name. The first three specific names 
are identified from the types ; the other two from the verj^ accu- 
rate descriptions given. The irregular corrugations of C. B. Ad. 
are abnormal, as are also the three ridges of McnJce. Normally, 
the shell is quite smoolb, with a rather glossy epidermis ; with 



276 MAZATLAN UNIVALVES 

the colour lighter than in C. incnrva, and disposed to break up 
into spots ; shaped like Emarginula rosea, vrith a very recurv- 
ed, distant and projecting vertex, a short, deeply sunk and 
slanting deck, and a hole above it passing up the spire. The 
characters are Kke some of the forms of Cr. incurva intensified ; 
and are subject to considerable variation. The mode of growth 
is as in that species ; but the planorbiform vertical ■whirls 
are even smaller, (about "01 across) with the apex deeply 
sunken. The smallest specimen is "15 in length ; the largest 
fotmd measures long. "84, Icit. '62, alf. '46. 

Aflatsp. „ -62, „ -48, „ 'IS. 

The shortest-decked specimen measures '16 from deck margin 
to the posterior, '39 to the anterior end, with an apical projec- 
tion of ■ 14. 

Sab. — Bodegas, California ; attached to dead and living shells 
and to each other, 6-10 fm. ; Hinds. — Straits of De Fuca, 
Gould. — Sta Barbara, Col. Jctcett. — Panama, extremely rare, 
C. B. Ad. — Mazatlan ; extremely rare ; L'pool Col. 

Tabtet 1357 contains 2 sp. very young. 1358, 1 sp. flat, 
margin extended. — 1359, 1 sp. coiflpressed, dark brown. — 1360, 
the largest sp., twisted growth, shghtly ribbed and corruga- 
ted. — 1361, 1 sp. pale flesh colour. 



339. Ceepidula incueva, Brod. 

Calyptra;a (Crepidida) incurva, Brod, Proc. Zool. Soc. 183s* 

p. 'to ■.-Tran.s. Zool. Soc. vol. i. pi. 29, f. 6—Mull. Syn. Not 

Test. Viv. p. 150. 
Crepidula incurva, B. 21. Cat. D'Orb. Moll. p. 49, no. 421.- 

C. B. Ad. Pan. Shells, p. 228, no. 347— (Crypta i.) E. if A 

Ad. Gen. i. 369. 
=«= Crepidula hopatica, Menhe, (uon Desk, nee C. B. Ad. ne 

Krauss,) Zeit.f. Mai. 1847, p. 184, no. 33. 

This species is known normally by the sharp longitudinr 
ridges on the back, which are not dependent on the attachmem 
being regular in growth, and conspicuous when adherent o 
smooth shells. It is much smaller than C. onyx, of a deepf 
chocolate brown colour, convex, with the beak very prominen 
smooth and black as in C. nigosa, Natt. The epidermis i 
rather thin and deciduous. There are however so many spec 
mens in which one or other of these characters paas away, thi 



MAZATLAN UNIVALVES 277 

it is not impossible that further researches may prove their 
identity. 

The vertex of C. incurva is discoidal and smooth, as in C. 
onyx, rather smaller, and more hidden by the subse(iuent 
growth of the shell. The earlier portion is very convex, smooth, 
nearly black. It develops ridges rather suddenly, strong 
enough to serrate the margin, which is then beautifully varie- 
gated with horn colour and tortoiseshell, and frefjuently rather 
spreading. As the shell advances, the ribs often pass away, 
leaving traces however by -which the species may generally be 
recognized. The deck occupies a larger or smaller proportion 
in different specimens, and is moi'e or less sunken, rarely 
developing a slight hole imder the vertex, approaching C. 
adunca. The spreading specimens generally assume a lighter 
colour, like C. onj^x, which in mode of growth and in the 
character of the deck they closely resemble. A large propor- 
tion of the shells are truncated in front, a,s though from 
living against a rising surface. The youngest. %jecimen is "07 
in length ; a large one, approaching C. ouj^x, and hving like 
an operciilum in the mouth of Uvauilla unguis, measures 

long. "9, lat. '6, alt. '25. 
A convex, spreading sp. ,, "92, ,, "67, „ '4. 

A narrow sp. ,, "82, „ '46, „ *33. 

Hah. — St. Elena and Xipixapi ; on dead shells in sandy mud 
6 — 10 fm. ; Cuming. — Payta, Fontaine. — Panama ; on living 
Gasteropods at and near low water mark, and on each other, 
common; C. B. Adams. — San Bias, Cajit. Wendt, (Meuke.) — 
Mazatlan ; on shells and on each other, not uncommon ; 
L'pool Col. 

Characters approaching C. onyx. Tablet 1362 contains the 
specimen in U. unguis. — 1363, 1 sp. nearly smooth, singularly 
indented. — 1364, 3 sp. scarcely striated, flat. — 1365, 3 do. 
convex, laterally compressed. — 1366, 3 sp. slightly striated, 
flattened, light coloured. — 1367, 3 do. very dark.— 1368, 3 do. 
more striated, light colour. 

Normal state. Tablet 1369 contains 3 sp. very young. — 

1370, 6 sp. diflerent ages, deck margin deeply angulated.— 

1371, 4 sp. sliglitly do.— 1372, 4 sp. slightly sinuated.— 1373, 
4 sp. flattened, broad. — 1374, 7 do. lighter colour, deck margin 
nearly straight, direction slanting.— 1375, 6 sp. deep, compress- 
ed growth. — 1376, 4 sp. twisted, vertex at the left. — 1377, 3 do. 
vertex at the right. — 1378, Columbclla fusca, with Crcpidula 
incurva, shewing attachment.— 1379, Pisania ha?mastonia, with 
July 1856. aa 



• 278 MAZATLAK TINIYALVES 

2 Cr. incurva in situ, one on the other. — 1380, 2 sp. with 
Bryozoa and Serpnla. 

Aberrant specimens. Tablet 1381 contains 2 sp. deck thin, as 
in C. nivea. — 1382, 1 sp. very convex, light coloured. — 1383, 
2 sp. deck variable in length. — 1384, 5 sp. margin irregular. — 
1385, 4 do. diseased. — 1386, 3. sp. form approaching C. adunca, 
jun.— 1387, 5 do. adult. 



310. Ceepidula onyx, Soto. 

C. t. solidiore, 2)lerii>nqiie lamellis, ad marginem s(epe, extiis 
rare apparentihus, instructa ; epidermide olivaced copiose in- 
dutd, irregnlaritcr lamellosa, hand nitente ; hahitii incrementi 
plerumque recto, seu incurvato, hand sjnrali ; planatd, sen in- 
terdum convexd ; colore hepatico, splendente, interdum nigriore, 
rare livido-carneo ; vertice nucleoso parvo, Imvi, discoidali, apice 
celato, prope marginem plerumque centraliter sito, stepissime ad 
marginem vecto et detrito ; testa juniore subcorned, castaneo 
maculatd, haud nigra ; septo interno solidiore, apaco, alho, 
striulas incrementi nisi marginem versus haud monstrante, 
margine plus minusve intU'S angulato, nee antice nee pottice 
distincte sinuato. 
Sow. Gen. Crepidiila, f. 2. 
Crvpta onyx, H. Sf A. Ad. Gen. i. p. 369. 
= Crepidula Phepatica, C. B. Ad. Pan. S/iells, p. 227, no. 346. 

(teste sp. typ. in Mus. Cum.) : non 2Ienle in Zeit. f. Mai. 

181.7, p. 184, no. 33. 
? = Crepidula hepatica, Desk. Enc. Metli. Yevs, 1830, vol. ii. 

p. 26, no. 7 : — Lam. An. s. Vert. vol. vii. p. 646, no. 12. — 

(Cropipatella h.) H. cf- A. Ad. Gen. i. 369. 
? = Crepidula hepatica, Krauss Sudafr. Moll. p. 69. no. 3, pi. 4, 

f. 12 a, b.—m-r. Ind. Mull. Guin. p. U, no. 92, pi. 5, f. 4, 5. 
= CalyptrcTa amygdalus, Val. Voi/. Ten. pi. 15, f. 3. 
Var. ? = Crcpidula contorta, ML-e. Zeit. f. Mai. 1851, p. 35, 

no. 121, (non Quoi/ Sf Gaim.) 
Juu. = Crcpidula Ce rithicola, C. B. Ad. Pan. Shells, pp. 225, 

320, no. 34:3. 
Comp. Crepidula rugoria. Xatt. in Jai/'s Cat. p. 107, no. 3043, bis.- 

Proc. Zool. Soc. 1856.— (Crypta. r.) H. cj- A. Ad. Gen. i. 369. 

"WTiether Deshayes described his C. hepatica from a Pacific or 
African shell is not known ; and whether the two arc identical 
has not yet been ascertained, the African specimens being 
generally too much worn for comparison. Krauss' var. com- 



MAZATIAN UNIVALVES 279 

planata appears exactly to correspond with tlie Pacific skell, to 
which it' is refeiTcd with certainty by Dkv„ with unwilling 
doubt by C. B. Ad. The shell quoted by him from Mke. 
appears (with hardly a doubt) to be C. incurra. The C. rugosa, 
Nutt. referred to this species by Jay, agrees in almost all 
respects ; but differs in the epidermis which though somewhat 
lamellar is glossy, never shaggy ; and in the young shell which 
is of a very dark colour, with a Velutina-shaped vertex. These 
most closely related species are however referred to difierent 
subgenera \)j Messrs. Adams. 

C. onyx begins life like a swollen Planorbis, about '013 
across, with the apex more or less concealed. It increases as 
in C. nivea, leaving the vertex free, submarginal, and generally 
medial, the shell increasiug in the plane of the vertex, so that 
the latter can only be seen when the shell is set on its side. 
At this period the body of the shell is light horn-coloured, 
with copious stains of tortoiseshell. As it increases, it develops 
the lamellose structure and shaggy epidermis of C. nivea, so 
that the light-tinted specimens of this can with difficulty be 
separated from the dark specimens of the other, the character- 
istic vertices being generally lost in the onward progress of the 
shell. The character of the deck, similar in the young shell, 
is strikingly different in the adult ; for while it develops the 
central angle, more or less, the extremities are not sinuated ; 
and the substance does not display strise of growth, except 
close to the margin, the principal part being opaque and 
uniform. In this it closely resembles C. incurva, from some 
varieties of which it can scarcely be distinguished. The outer 
surface very rarely develops faint longitudinal undulations, 
(never sharp ridges as in C. incurva) probably from adher- 
ing to ribbed shells. Even in specimens with the epidermis 
very fresh, it is often rubbed smooth at different angles on 
the back, Pfrom adhering to pebbles rolled by the tide. The 
inside is richly lustrous, generally brilliantly hepatic, rarely 
blackish brown, most rarely of a light flesh colour. The 
smallest (imperfect) specimen is '07 long; aflat sp. (convex 
when young) measures long. 1*04, lat. "7, alt. '1. 

A twisted sp. „ 1-36, „ -9, „ -6. 

The largest sp. „ 22, „ 13, „ -Q. 

This shell weighs '66 oz., and displays a thickness of laminEC 
amounting at the umbo to '43 in. 

jffal. — Panama; on Strombus Peruvianus and other shells, 
rare ; C. B. -4c?a??is.— Mazatlan ; very rare, on shells, &c. 



280 MAZATIAN UNIVALVES 

IJpool Col. — [C. ? liepatica : Benguela and Loander, very 
common and variable, Tarns: Tafel Bay and Natal, 'Krauss^^ 

Tablet 1388 contains 3 sp. very young. — 1389, 4 sp. different 
ages, finely grown. — 1390, 2 sp. form approacliing C. inciirva ; 
one very dark. — 1391, 1 sp. witb irregular ridges, passing to 
tbe form Lessonii.— 1392, 1 sp. twisted, apex lateral.— 1393, the 
largest specimen. — 1394, 1 sp. light coloured, slightly rayed 
with darker. — 1395, 1 sp. very light coloured, beginning con- 
vex, suddenly becoming flat and slightly rayed in the middle. 

Tablet 1396 contains 2 young sp. var. Lessonii, probably 
belonging to this species, but perhaps to C. nivea. 

341. Cbepidula nivea, C. B. Ad. 

Or. t. ellipticd, suhrotundata, seu maxime elongatd ; tenui, 
sen incrassatd ; intus nivea, lineis castaneis radiantihus swpe 
omatd ; sublcevi, seu irregulariter concentrice plus minusve 
rugosd, seu lamellis extantibus varie instructd ; limbo aeuto, 
seio maxime planato, lamelloso ; epidermide coxiiosd irregulari- 
ter lamellosd ; superjicie seu striulis coneentricis seu (sub lente) 
rugulis radiantibus varie ccelatd ; habitu incrementi via spirali;^ 
vertice nucleoso, minimo, Velutincp. simili, apicem monstrante, 
castaiieo, rare albo, rugis coneentricis conspicuis in^tructo, satis 
prominente, spiralifer subilo augente, dextrorsiim dejlecto, a mar- 
gine vix remoto, scape ad marginem vecto et detrito ; septo plus 
minusve in medio angulato seu sinuato, ad sinistram partem 
plus minusve profunde, ad dexfram parum sinuato, tenui, lineas 
incrementi, haud lineam centralem monstrante. 

a B. Ad. Pan. Shells, 1852, pp. 234, 320, no. 351 : diagn. 

auct.— (CrjTta n.) JI. Sr A. Ad. Gen. i. 369. 
+ Calyptra?a (Crepidula) Squama, Brad. Pi'oc. Zool. Soc. 1834, 

p. 40 -.—Tram. Zool. Soc. vol. i. p. 205, pi. 29, f. 10.— Mull. 

Syn. Nov. Test. T7('. p. 151. — (Crepidula s.) Lam. An. s. Vert. 
' vol. vii. p. 618, no. 16.— C. B. Ad. Pan. Shells, no. 649, 

p. 229.— (lanaous s.) E. tj' A. Ad. Gen. i. 370.— ? = Crepidula 

Goreensis, Ml-c. Zeit.f. Mai. 1851, p. 36, no. ViA. 
+ Crepidula striolata, Mke. Zeit.f. Mai. 1851, p. 35, no. 123. 
+ Calyptraja (Crei>idula) Lessonii, Brod. Pj-oc. Zool. Soc. 1834, 

p. 39 -.—Tran.s. Zool. Soc. vol. i. p. 204, pi. 29, f. b.—Mull. 

Si/n. Nov. Test. Viv. p. 149.— (Crepidula L.) Lam. An. s. Vert. 

vol. vii. p. 649, no. 2<3.— (lanacus L.) H. Sf A. Ad. Gen. i. 

p. 370. 



MAZATLAN UNIVALYES 281 

= Crepidula unguiculus, var. Brod. va. Mas. Cum. — [lanacus 
Tinguiculus, Soio. ?ubi) H. Sf A. Ad. Gen. i. 370. 

? = Crepidula Patagonica + C. protea, D'Orb. (pars,) B. 31. Cat. 
Moll. p. 48, no. 416, 417. 

Comp. Crepidula Navicelloides, N'lctt. in Jai/'s Cat. p. 107, 
no. 3035, {Upper California.) 

Comp. Crepidula explauata, Gould, Cal. Sf Mex. Shells, p. 4, 
pi. 14, f. 7. = Cal^-ptrsea perforans, Val. Voy. Ten. 1846, pi. 24, 
f. 9, 9 a, b. [The author seems to imply that the creature 
burrows : the specimen Tepresented however has evidently 
been developed in the hole of a Lithophagus.] = C. exuviata, 
mdt. in Jay's Cat. p. 107, no. 3027. 

This creature, when flat and finely grown, is the C. squama 
of Brod. The same shell, when coarsely gi-own, more convex 
and without brown stripes, is the C. nivea of C. B. Ad. When 
the layers of which C. nivea is composed, instead of lying 
regudarly one over the other, are slightly prominent, it becomes 
the C. striolata, Mke. When they arc drawn forwards and 
project, it becomes the C. Lessonii, Brod. The name of Prof. 
Adams is retained, in preference to the prior ones of Broderip 
and Menke, as representing the normal condition of the shell. 
The name C. unguiculus has priority, but does not ajipear to 
have been published. Among tke specimens marked C. protea 
and C. Patagonica by D'Orb. in his collections, there are 
several which seem to belong to this species ; others to C. onyx, 
&c. V. supra. Both arc refe-rred by Dr. Gray to C. ddatata, 
(B. M. Cat. D'Orb. Moll. p. 49.) 

C. nivea begins life as a minute Velutina-shaped body, with 
a sunken apex and coarse concentric folds. When this has 
grown to about '015 across, it suddenly enlarges itself, throws 
a columeUar lip over the base of the shell, raises a more or less 
prominent margin round it, so as to surround the vertex, and 
comraences its septum at an angle from the columeUar lip 
varying from about 90° at the posterior to 130" at the anterior 
end. The smallest shell found measures "015 in length, on 
which these stages are distinctly traceable. The septum is at 
first straight, then angvJated in the middle, lastly with an 
anterior sinus. 

In the 'squama' stage, it appears as a very thin flat shell ; 
with the vertex generally lustrous brovra, sometimes white ; 
from this radiate a greater or less number of brown lines, 
gometimes more or less broken into dots, gradually losing 



882 MAZATLAN UNIVALVES 

themselves in the white texture of the shell, sometimes re- 
appearing at the margin, sometimes altogether absent. Very 
rarely a rich lustrous browu is developed inside, as in C. onyx, 
shading into a sea-weed green. The shell is covered with a 
copious .yellowish-green epidermis, -^hich lies in a fringe round 
the sharp margin. Under this, the surface presents concentric 
striae of growth, and very fine longitudinal corrugations. Either 
of these however may disappear, or be developed at the ex- 
pense of the other. The vertex is either ui tho margin, or as 
much as '08 removed from it ; it is not imbedded in the sur- 
face of the shell as in C. unguiformis, but is slightly prominent, 
displaying its rugose folds. Both these and the vertex itself 
are often rubbed off. 

In its ordinary state, the texture has a tendency to run into 
layers. The epidermis does the same, the layers being in 
shreds and very copiovis. These layers in the adult are often 
continued to the margin, making it broad and flat. At other 
times they stand out .more or less on the back of the shell. 
Sometimes the shell advances longitudinally, making layers at 
more or less regidar intervals, becoming then the aberrant 
form C. Lessonii ; which is however connected by such gradual 
links, through C. striolata, with the t.ypical C. nivea, as not to 
admit of separation. In this form, (common in some places, 
but extremel.y rare at Mazatlan, the vertex is generally left 
behind and rubbed off: in the onl.y S. American specimen in 
W'hich it was found, it exactly agreed with the remarkable 
character of C. nivea. The specimens in Mus. Cuming from 
Vancouver's Str. (without authority,) are large and spreading ; 
with the apex small and ribbed as in C. nivea, but white. 

Of the shells collected by Mr. jSTuttall at Monterey &c., some 
want the vertex, but otherwise resemble C. nivea : one very 
young specimen however has a specifically diflerent vertex, 
more resembling Cr. fornicata, &c. The C. explanata of Gould 
is probably a variety of the Montere.y shell, caused by living 
in the hole of a Lithophagus ; similar forms of C. nivea being 
found among the !Mazatlau shells. It differs in the cancellated 
structure between the lamiuoe, which however Is not seen in 
the Cumiugiau specimens. In its j'oung state, the shape is 
normal. If the species should prove distinct, the name of 
Gould must take the place of the prior names of JS^utt. and 
Val., the former not having been described, and the latter 
representing an untruth. 

The growth of C. nivea is rather straight, after the nuclear 
portion is completed, with the vertex submedial or directed 



MAZATLAN UNIVALVES 283 

fco the riglit : sometimes liowever it is rather spiral, resembling 
C. aculeata. The deck margin generally has a more or less 
re-entrant angle in the middle. This however is sometimes 
rounded ; sometimes nearlj^ straight. The sides are either 
sti-aight or lobed. The anterior sinus is either very deep or 
scarcely perceptible. The sinuated part is sometimes callous. 
The surface of the deck is generally thin, displaying fine striie of 
growth. The inner surface is either veiy glossy, or (under the 
microscope) most finely corrugated. The coloured lines are 
extremely variable in the same specimen, being often conspicu- 
ous when young and suddenly ending. Very young shells 
were extremely rare. The animal hollows out a place for itself 
on Patella Mexicana, &c. ; but no shelly dcp'osit has been ob- 
served. The largest sp. measures long. 1'95, lat. 1'35, alt. '46. 
Aflatsp. „ „ 1-46, „ 1-02, „ -14 

A rounded, convex sp. „ ,, "77, „ "68, „ ■2G. 

An elongated sp. ,, ,, 1'35, ,, "6, ,, "3. 

Sp. a. Deck margin from vertex '77, from opposite end '45. 
Sp. b. "53, ,, ,, '8. 

Sab. — Mazatlan ; abundant ; L'pool Col. — (C. nivea) Panama ; 
under stones near low water mark, not common ; C. JB. 
Adams. — (C. squama) Panama, Caming : — do. under stones 
and in dead shells near low water mark, not common ; 
C. B. Adams. — (C. Lessonii) Isle of Muerte ; under stones 
at low water ; Cuming, — Panama, do. common ; C. B. Ad- 
ams. — Vancouver's Straits, Mus. Cuming. 

Form squama. Tablet 1397 contains 8 sp. very young, of 
different sizes. — 1398, 17 sp. different ages, striped. — 1399, 5 
sp. difiercnt ages, colour not conspicuous. 

Form nivea, normal. Tablet 1400 contains 6 sp. finely 
grown, with brown rays outside. — 1101, 6 sp. do. without 
brown raj^s. — 1402, 7 sp. with broad laminated margin ; one 
sp. measuring 1*7 outside, and 1'38 within ; another, measuring 
'97 within, has an apical margin "32 across. — 1403, 4 sp. rough, 
laminated outside. 

Forni striolata. Tablet 1401 contains 4 sp. beginning as 
squama, developing a few slight ridges. — 1405, 5 sp. form nivea, 
irregularly developing ridges. — 1406, 6 sp. ridges more deve- 
loped ; one being convex and closely ridged from the begin- 
ning. — 1407, 2 sp. Lcssonii-iovm. developed, lamina; close. — 
14/)8, 3 do. very irregular. (The two larger sp. are from a 
dealer, locality imkuowu, but among other Mazatlan sheUa.)— 



284 MAZATLAN UNIVALVES 

1409, 1 sp. finely developed, with coloured rays, laminae con- 
centrically striated. 

Aberrant specimens. Tablet 1410 contains 1 sp. longitudin- 
ally ribbed (from adkerent surface.) — 1411, 7 sp. margin 
irregular. — 1412, 3 sp. margin curved. — 1413, 3 sp. flat and 
recurved, form of C. unguiformis.— 1414, 6 sp. posterior margin 
expanded. — 1415, 3 sp. subspiral, approacliing C. aculeata. — 
1416, 1 sp. deck elongated.— 1417, 3 do. deck very sliort.— 1418, 
3 do. colour developed inside, brown passing into green. — 1419, 
1 sp. sliewbig under layer of deck, striated. — 1420, 1 do. dis- 
eased.— 1421, 1 do. deck solid, as in C. onyx.— 1422, 1 do. flat, 
concentric striae conspicuous. — 1423, 3 do. longitudinally cor- 
rugated. 

Tablet 1424 contams a portion of Spondylus calcifer, pre- 
sented by R. D. Darbiskire, Esq. containing in situ 4 sp. 
Petricola robusta, 1 Cumiugia, 2 Litbophagus plumula, 1 G-as- 
trochaena truncata, and 1 Crepidula nivea. This is greatly 
elongated, 1 '55 by "72, muck arcked, and witk very numerous 
layers. Its position in a burrow of Litkopkagus kas preserved 
the apex from detrition.— 1425, 1 sp. stiU more elongated, from 
tke bun-ow of a Litkopkagus in Ckama, closely resembling 
C. explanata, Gould. 

Specimens shewing decTc margin. Tablet 1426 contains 3 sp. 
sinus sligkt, center more or less deeply augulated. — 1427, 6 sp. 
sinus deep, center nearly straigkt, more or less angulated or 
sinuated.— 1428, 1 sp. witk abnormal central ridge. 

Tablet 1429 contains 2 young shells wkick probably belong 
to this species, though the apex has been rubbed smooth. 



342. Ceepidula Pungttifoemis, Lam. 

Patella crepidula. Linn. 8t/st. Nat. p. 1257, no. 7o2.—Dillw. 

Descr. Cat. p. 1021, no. 13. 
Crepidula unguiformis. Lam.. An. s. Vert. vol. vii. p. 642, 

no. 'L—Brod. Proc. Zool. Soc. 1834, p. 39.— C. B Ad. Pan. 

SMls, p. 230, no. 350.— (lanacus u.) -H". ^ A. Ad. Gen. i. 

p. 370. 
Crepidula Italica, Defr. Diet. Sc. Nat. vol. xi. p. 397. 
Crepidula plana. Say, Joitrn. Ac. Nat. Sc. Phil. vol. ii. p. 226. 

(teste Gould 4* C. B. Ad. non Desh.) 
Comp. Patella Goreensis, Gmcl. p. 3694.— i>(7Z7i'. Descr. Cat. 

p. 1020, no. 12.— (Crepidula G.) Desh. in Lam. An. s. Vert. 



MAZATLiiK UNIVALVES 285 

vol. vii. p. 645, no. 10— Mke. in Zeit. f. Mai. 1851, p. 36, 
no. 124— (Crypta G.) H. S," A. Ad. Gen. i. p. 369— (Le 
Jenac,) Ada7is. Coq. de Sen. p. 41, pi. 2, f. 10. 
For other references, v. C. B. Ad. loc. cit. 

The late lamented and most accurate Prof. Adams, ^ ho in 
all other instances has created fresh species sooner than allow 
that the same shell eoidd be common to the Atlantic and 
Pacific waters, has here, and here only, departed from his 
theory, and has quoted the above shell from the following six 
zoological provinces, to which we must now add a seventh : — 
1. Mediterranean — 2. East coast of North America, North of 
Cape Cod. — 3. Do. South of the Cape. — 4. The Carriljean 
waters. — 5. West tropical America. — 6. S. W. temperate 
region. Also fossil in Italy, Morea, Bordeaux, Dax and Tour- 
aine, Desk. "Fossil nel Piacentine e nel Sauese," Broc. And 
yet it is not impossible that in this his only instance, he may be 
in error ; and that the shells he has quoted from Panama (with 
those of Brod. from Panama, perhaps from Chiloe,) are varie- 
ties of his own C. nivea ; as the shells of D'Orbiguy, qixoted by 
him under this species, are said by Dr. Gray (B. 31. Cat. 
D'Orb. Ifoll. p. 49, no. 418,) perhaps not correctly, to be 
varieties of C. dilatata. The form either of margin or of deck 
is not to be relied on in shells of this type. 

On examining however the young shells classed as C. nivea, 
it was found that some of them differed from the rest in the 
following particulars. 1. The spiral vertex is much larger, 
being, in a shell ■ 095 long, "025 across. 2. It is smooth, not 
concentrically wrinkled. 3. It is sunken in the produced mar- 
gin of the shell, not prominent as in C. nivea. 4. It expands 
so evenly, that it is difficult to fix upon the point at which the 
spiral part ends. 5. The large spire shews conspicuously 
through the eolumellar lip, (at an angle from the deck, as in C. 
nivea.) 6. The epidermis appears much thinner. In all other 
respects, its mode of forming the deck, the shape of its margin, 
the white colour often streaked with brown, and the tendency 
to grow in layers, it agrees exactly with the larger species. 
Whether these characters are peculiar to the shells of the 
ordinary form Cr. ungiiiformis, which dwells in dead shells 
and is therefore liable to transportation through all seas, I 
cannot tell, as the vertices are rarely perfect, being lost at the 
advance of the shell. It is however worthy of examination 
by those who have access to young shells on the Atlantic coasts. 
That two shells, so very similar and similarly variable in the 



286 MAZATLAN TTNIVALVES 

adult state, should be so different in their early stage, is very 
remarkable, A series of specimens from the inside of a West 
African Pinna, of which the youngest is only "01 long, agree 
exactly Tvith the Mazatlan specimens now described. The 
largest, 1'18 in length, would certainly have been called C. 
squama if from Panama, though the epidermis is thinner than 
in the ordinary INIazatlan specimens. They go through the same 
changes of colour, deck margin, &c. as C. nivea ; and if they 
had been born in an empty Cowry would probably have deve- 
loped into the genuine C. "unguiformis. As it is, they are 
probably the C. Goreensis,* a species which, according to 
DillwjTi, has a tendency (like C. nivea) to develop foliations. 
Whether the specimens quoted by Mcnke as C. Goreensis 
belong to this species or to C. squama, cannot be told without an 
examination of the vertex. Shells of exactly the same species, 
some extremely young and well formed, others of the true C. 
unguiformis shape, circular and elongated, were found in dead 
East Indian Cowries from Singapore The species may abound 
at Mazatlan ; but as almost all the vast nunabers of shells sent 
were perfectly fresh, there is no knowing what the dead ones 
contained. The largest Mazatlan shell with the apex perfect 
measures long. '12, lat. "08, alt. '02. Others, which have lost 
the apex in growth, may belong either to this species or to 
C. nivea. 

Hah. — Mediterranean, Africa, Singapore, North and South 
America, East and West ; fossil in tertiary strata ; v. supra. — 
Callao, Peru, ver\' fine, in dead shells, B. M. Col. D' Orbigny, 
not in Cat. — Mazatlan ; extremely- rare, in dead shells, &c. ; 
Uimol Col. 

Tablet 1430 contains 3 sp. yovmg. — 1431, an adult sp. in 
empty Trivia radians. 



Genus CEUCIBULUM, Schum. 

Cnicibulum, Schum. Ess. no. 8, 1817 : — G-ray, Troc. Zool. Soc. 

1847, p. 157, no. 270 i—H:. Sf A. Ad. Gen. vol. i. p. 365. 
Dispotsea, Say, Journ. Ac. N. S. Phil. vol. iv. 1124. 
Calypeopsis, Lesson, 1830, Brod. 1834. 

• The young of Cr. fomicata, as appears from specimens from Statenliland 
in the collection of K. M'Aiiilrew, Escj. is of the type Cr. Goreensis, &mel. but 
with only one large tumid whirl (as in Cnicibulum imbricatum,) lying imbedded 
in the normal portion. Inside with first deck at an angle with the succeeding. 



MAZATIAN tJNlVALVES 287 

Distinj^uislied by its complete cup, attached at its vertex, 
and generally more or less along one side. Great confusion 
attends the synonymy of the species, the names extinctorium, 
inigosa, imbricata & auricidata having been used by different 
authors to denote very different species. 

343. Cetjcibulum imbeicatxtm, Sow. 

Calyptraea imbricata, Sow. Gen. f. 5. — Desk, in Lam. An. s. 

Vert. vol. vii. p. 636, no. 33. — C. (Dyspotoea) imbricata, Mke. 

in Zeit.f. Med. 1847, p. 185, no. 36.— C. (Calypeopsis) .imbri- 

cata, B. M. Cat. B'Orh. Moll. p. 47, no. 409. 
Jun. = Calyptraea imbricata, Brod. Proc. Zool. Soc. 1834, 

p. 36 -.—Trans. Zool. Soc. vol. i. p. 193, no. 7, pi. 27, f. 7.— 

C. B. Ad. Pan. Shells, p. 222, no. 336. 
= Crucibulum scutellatum, Gray, in Mus. Cuming. = Patella 

scutellata, [Graij in] TFoocZ, (B. M. ms.) Ind. Test. Suppl. 

1828, p. 26, pi. 8, f. 4.* 
= Calyptraea (Calypeopsis) rngosa., Less. Voy. Cog. no. 158 : — 

Guer. Mag. Zool. 1839, pi. 2. — (Non. Besh. in Lam. An. s. 

Vert. vol. vii. p. 637, no. 34 : = C. lignaria, Brod.) 
Var ? = Crucibulum .Pimbricatum, ?'«;■. Broderipii, Proc. Zool. 

Soc. June 1855. — =Cahi)traea (Calypeopsis) rugosa, pars, 

B. M. Cat. B'Orb. Moll. p. 47, no. 408. 
= Calyptrsa aurieulata, P. P. C. Cat. Prov. (non Chemn.) 
+ "CalyptrEea extinctorium?" Soiv. Gen.f f. 3. — (Non Lam. 

An. s. Vert. vol. vii. p. 622, no. 1.) — Crucibiilum extinctomm, 

ff. Si- a. Ad. Gen. i. 366. 
= Calj-ptraea rugosa, Val. Voy. Ven. pi. 14, f. 1, (male.) — Bve. 

Conch. Syst. pi. 141, f. l.-(Xon Besh. loc. cit.) 
= Calyptra;a (Dyspotfea) dentata, Mke. in Zeit.f. Mai. 1847, 

p. 185, no. 35.— C. B. Ad. Pan. Shells, p. 221, no. 334. 
Jun. ?= Calyptra;a auricularis, Besh. in Lam. An. s. Vert. 

vol. vu. p. 639, no. 40 : — Enc. Meth. Vers, vol. ii. p. 176, 

no. 18.— (Non Patella aurieulata, Chemn.) 
Comp. Calyptraea PPimbricata, var. Cumingii, Proc. Zool. Soc. 

June, 1856. — =C. rugosa, pars, B'Orb. loc. cit. (non Desh.) 

* Although thi3 name was published first in time, yet as no description is 
given, and as the species cannot be recognized in the miserable figure, (as appears 
from itshavii^ been overlooked bybothiSoKJ. kBrod.,) it does not appear entitled 
to priority. For the same reason the P. Feziza is laid aside, which may be the C. 
spinosa, Soto. 

t Of this shell no outside view is given ; bnt as the inside exactly corresponds 
vfith the C . imbricatum, while it is given as a distinct species, it is fair to conclude 
th at it is intended for the uou-pitted Tariety of that form. 



Zoo MAZATLAN UNIVALVES 

Comp. Calyptra?a gemmacea, Tal. Toy. Ven. pi. 15, f. 2. [If 
the figure be accurate, this is a distinct, tubercled species : 
but it maj'^ be a small, conical, worn C. imbricata ; the quasi- 
tubercles being worn ribs.] 

The pitting of the intercostal spaces which seems to form the 
ground of separation between C. imbricata of Soio. and C. 
dentata of J/Xt. appears so very variable a character, that I 
have not ventured to regard them as distinct. The Mazatlan 
specimens (when in sufficiently fine condition to speak with 
certainty) are never wholly without pits : yet they are com- 
pletely irregular in their formation, often not being seen over a 
great portion of the sm-face ; not unfrequentlj^ appearing on one 
side only ; and very rarely traceable on the young shell. The 
species is normally rather solid, conical, with a very variable 
nimiber (about 20) of stout rounded ribs, more or less spread- 
ing out at the margin. Fresh ribs are frequently formed in 
the intercostal spaces. "When a fresh margin is formed below 
the pahnations of the former one, a series of pits is produced. 
As the palmations are most developed in the adolescent state, 
so are the pits. They are rare in the older growth. Both ribs 
and intercostal spaces are finely, but irregularly indented with 
radiating corrugations. Fine radiating brown lines are often 
traceable outside, dotting the interior margin. The surface 
is generally rough and often covered with accretions ; the 
vertex is rarely preserved. 

In Mr, Darbishire's collection, is a specimen with the animal 
matter ili-ied within, and the young fry covering the principal 
part of the inner surface of the shell. These are shaped like 
Vanikoro, about "035 across ; with the apex flat, not sunken ; 
with one tumid whirl exposed, and a very large umbilical area. 
The surface is concentrically and very finely fm-rowed. Most of 
the specimens have made a faint lip over the base, with an edge 
which is to commence the margin of the Patelliform shell ; but 
the cup is not begun. In this stage, the shell cannot be dis- 
tinguished generically from Crepidula. The nuclear whu-ls are 
turned laterally with the plane of after growth (as in Capulus), 
perpendicularly to the base of the shell. The smallest specimen 
found in the adolescent stage is ' 17 across ; at which period 
it greatly resembles the young of Crepidula dorsata, the ribs 
not being developed. The cup is then semicircidar, produced 
in front, adhering at the two separate margins. As it inweases 
in size, the anterior margin bends round till it joins the 
posterior one, forming an entire cup, adherent alnjost to the 



MAZATLAN tTfTIVALTES 289 

top. In this respect it differs from C. umbella. Desk. (Lam. 
An. s. Vert. vol. vii. p. 635. no. 30, = C. rudis, Brod. Proc. Zool. 
Soc. 1834, p. 35,) and the W. Indian form C. auriculata, Chemn. 
Conch. Cab. vol. x. f. 162S-9 ; . of which, though common in 
S. W. Mexico fP. P. C.J, not a single specimen was found 
in the Mazatlan collection. This latter species is generally 
longer, more spreading, of a lighter colour, and with the cup 
only adherent close to the vertex. The ribs are also less 
developed, and never pitted. The Calyptrsea auricularis of 
Deshayes may be the young of either species. The Mazat- 
lan shell is generally of a rich metallic brown, displaying a 
lighter or -deeper tint, sometimes nearly black ; rarely of a 
light grey or flesh colour ; occasionally tinted with green. The 
cup is always white, with transparent lines of growth. Its 
inner margin is scarcely flattened, and not angulated as in C. 
spinosa. When the creature lives on hard pebbles, there is 
generally an extremely thin shelly deposit : when on shells, a 
well marked excavation. 

Aflat, spreading sp. measures long. 2'1, lat. 1*8, alt. "65. 

A conical one „ „ 1-28, „ 1'15, „ 72. 

Sab. — ^Lower California, Major Rich. — Bay of Magdalena, 
Gulf of California, KeU.ett.—S. W. Mexico, P. P. C.—Ac- 
apulco, CoL Jewett. — Panama, very rare, C. B. Adams.— 
Mazatlan ; not uncommon, on stones, dead shells, and 
each other; Z'pool Cc^^. — Straits of Magellan; [p] Mr. 
J. Rohertson, B. M. 

Tablet 1432 contains a group of the fry, presented by E. D. 
Darbishire, Esq. 

Tablet 1433 contains 7 sp. very young. — 1434, 5 do. young. — 
1435, 4 do. adolescent.— 1136, 8 sp. shewing gradations of col- 
our from very light to nearly black.— 1437. 4 sp. varying from 
very much to scarcely pitted ; margin much or scarcely palma- 
tcd. — 1438, 4 do. varying from very conic to spreading ; ribs 
few (20), with large palmations, or many (42), with very small 
ones. — 1439, 1 sp. with a young one adhering. — 1140, 2 sp. 
worm-eaten, cup diseased.— 1141, 1 sp. on Ostrea Virginiea. — 
1442, a stone with thin shelly attachment. — 1445, UvaniUa 
olivacea, with attachment of a Calyptra^id. — 1414, A fragment 
of primitive rock, with 5 sp. in situ : (presented by J. Hib- 
bert, Esq.) 

Aug. 1856. lb 



290 mazatian univalves 

344. Ceucibulitm spinosum, Sow. 

Cal.AT)tr8pa spinosa, Sow. Gen. f. 4 : var ? f. 7. — I^am. An. s. 
Vert. vol. vii. p. 636, no. 32.— Var. Brod. in Trans. Zool. Sac. 
vol. i. pi. 28, f. 8.— C. (D.vspotffia) sp. Mke. in Zeit. f. Mai. 
1851, p. 36, no. 127.— (Crucibulum sp.) ff. Sc A. Ad. Gen. i. 
366. 

= Patella Peziza, Wood, (B. M. ms.J Suppl. Ind. Test. 1828, 

p. 26. pi. 8, f. 3. 
= Calyptrs;a tubifera, Less. Voy. Ven. pi. 14, f. 2. (Ordinary 

form, with, short, crowded spines.) — "Dispolia" tubifera, 

Say, [probably a misprint,] in B. M. Cat. B'Orb. Moll. p. 47, 

no. 410. 
= CaljT)tr£ea (Calypeopsis) auriculata, D'Orb. B. M. Cat. Moll. 

p. 47, no. 410. — (Non Patella auriculata, Cliemn. v. Troc. 

Zool. Soc. June, 1856: comp. C. umbrella, Desh. = C. rudis, 

Brod.J 

+ C. (Calypeopsis) tenuis, Brod. Proc. Zool. Soc. 1834, p. 36 : — 
Tra7is. ^Zool. Soc. vol. i. p. 199, no. 9, pi. 27, f. 9.— Lam. An. 
s. Vert. vol. vii. p. G37, no. 35. 

+ C. (Calji:)eopsis) klspida, Brod. Proc. Zool. Soc. 1834. p. 37 : — 
Trans! Zool. Soc. vol. i. p. 200, pi. 27, f. \0.—Mull. Syn. Noc. 
Test. Viv. p. 144. — Lam. An. s. Vei^t. vol. vii. p. 638, no. 36. — 
Bev. Zool. Cuv. Soc. July, 1838.. — Chenu, Lee. Elem. p. 144. 
f. 464— C. B. Ad. Pan. Shells, p. 221, no. 335.— (Crucibu- 
lum h.) H. ^ A. Ad. Gen. i. 366. 

+ C. (CaljTjeopsis) maculata, Brod. Proc. Zool. Soc. 1384, 
p. 37 -.—Trans. Zool. Soc. vol. i. p. 200, pi. 27, f. W.—Miill. 
Syn. Nov. Test. Viv. p. 145. — Lam. An. s. Vert. vol. vii. 
p. 638, no. 36.— i?f i'. Zool. Cuv. Soc. Jul}-, 1838.— C. B. Ad. 
Pan. Shells, p. 223, no. 337.— (Crucibulum m.) H. Sf A. Ad. 
Gen. i. 366. — (Non C. maculata, Quoy Sf Gaim. Voy. Astr. 
vol. iii. p. 422, pi. 72, f. 6, 9 : — Lam. An. s. Vert. vol. vii. 
p. 628, no. 10. 

Comp. Cal^iJtraja rugosa, Desh. Enc. Meth. Vers, vol. ii. p. 173, 
no. 9 : — Lam. An. s. Vert. vol. vii. p. 637, no. 34. — (Non 
C. rugosa, Less. Voy. Coq. and Guer. Mag. : nee Val. Voy. 
Ven.) 

= C. (Calypeopsis) lignaria, Brod. Proc. Zool. Soc. 1834, p. 36 : — 
Trans. ZmI. Soc. vcl. :. p. 198, no. 8, pi. 27, f. 8.— Var. loc. 
cit. pi. 27, f. 8*. 



MAZATLAU UNIVALVES 291 

+ Calyptrsea (Calypeopsis) quinquina, Less., B. M. Cat. D' Orb. 

Moll. p. 47, no. 407.— ( = C. Byronensis, Gray in B. M.J 
+ Calyptrsea (Calypeopsis) rugosa, pars solum, B. M. Cat. 

D'Orb. Moll. p. 47, no. 4^8 ; syn. plur. excl. 

Comp. C. (Calypeopsis) radiata, Brod. Proc. Zool. Soc. 1834, 
p. 36 -.—Trans. Zool. Soc. vol. i. p. 198, no. 6, pi. 27, f. 6.— 
Zam. An. s. Vert. vol. vii. p. 635, no. 31.— C. B. Ad. Ban. 
Shells, p. 223, no. 339.— (Non C. racliata. Desk. 1836, An. s. 
Vert. vol. vii. p. 628, no. ll. = Galerus.) 

It is not surprising that tliis beautiful species lias been 
described under sucb a variety of names, as the differences 
between individuals are patent at first sight ; their affinities 
only after a careful examination of a large multitude of speci- 
mens. And yet, though it would be most difficult to frame a 
description that should include the whole and exclude neigh- 
bouring species, the general habit of growth is such that it is 
not difficult to recognize. The IMazatlan specimens alone 
prove the C. tenuis, C. hispida and C. maculata, of Brod. to be 
merely forms of growth of C. spinosa. Sow., which pass into 
one another by such gradual steps that they cannot be separ- 
ated even as varieties. The supposed differences observable 
in the Cumingian types are as follows. C. imbricata, olim (one 
of two shells differing specifically from each other, and each 
claiming the name of Brod. to the confusion of students ; an 
error now corrected) was the young state, before the cup is 
entirely formed : C. tenuis, the smooth, white, streaked form : 
C. hispida, the young state of the white shell, with small 
spines ; C. maculata (non Quay), a rather older stage, smooth 
and spotted. The C. radiata, in most respects agreeing with 
C. spinosa, differs in the remarlcable flattening of the cup, and 
in its greater separation from the margin. 

The C. quiriquina of Lesson and D'Orbiguy, (which is the 
C. Byronensis, Gray ms.) belongs to a Southern type which 
may be distinct ; though it has characters enough in common 
to make it not impossible that it is only a coarse variety. It 
is characterized by a more solid texture, light I'eddish brown 
colour, entire absence of spines, and a less angulated cup. To 
this form is referable, as an aberrant, variety, the C. lignaria 
of Brod., which is the C. rugosa of Desk, (not Less.) and in 
pai't of D'Orb. These shells are always conical and Hipponi- 
eoid ; which is accounted for by their growing on a narrow 
base, either on small pebbles, or attached to each other. On 



292 MAZATLAN TTNIVALVES 

this form are sometimes seen faint radiating ribs, which are 
quite abnormal, and are perhaps due to the inconvenient shape 
into which the creature finds itself driven.* 

• As D'Orbipny seems to have confounded both species and synonyms in this 
family, the followinp; account of his type specimens in the Br. Mus. (mostly dead 
Bhells) may be useful to students. His own names and synonyms are given in 
quotations : the numbers are those on the tablets. 

659, 560, "C. rugosa = imbricata. Sow." are the true Crncibulum imbricatum ; 
not C. rugosa, Desh. 

661, "C. rugosa, X>«sJ. = tenuis, Brod." is neither one nor the other; bnt = 
C. ? imbricatum, var. Broderipii, Froc. Zool. Soc. June, 1856. 

656, "C. rugosa, Desk. = rudis, Brod." is neither ; but appears the shell described 
in Proc. loc. cit. as C. ?P iitbricatum, var. Cumingii. 

683, "C. tubifera, !Ee«s. ^ spinosa, iSoic. ^ auriciilata, CAem." is the true Crnci- 
bulum spinosum; but quite distinct from Patella auriculata, Chem. which 
appears to be the W. Indian form of C. umbrella, Desk. = rudis, Brod. 

555, "C. quiriquina" is the dull, thick, spineless ? variety of Crucibulum spinosum, 
^Byronensis, Grai/, 

657, "C. rugosa, Desk." is an interesting intermediate form between the last and 
the next, of the shape of Scurria mitra. Less. ^ Each., and sometimes develop- 
ing a very few ribs . 

658, "C. rugosa = lignaria," rightly named; the extreme form, lite the largo 
fossil Hippouyx. 

666, "C. intermedia" is a Galerus, apparently distinct from any of Broderip's 
species. 

665, "C. mamillaris, & C. lorica [Plichen] Brod." is not the Galerus mamillaris, 
but the Galerus unguis, Brod. 

667, "C. pileolus" intermediate in character between Galerus and Trochita. 

- - - , "C. Patagonica" is probably a variety of Crepidula dilatata ; as also may 
be , "0. foliacea", in spite of its rugose surface. 

673, "C. protea" are probably dead specimens of Crepidula incurva, or C. onyx, 
or both. 

674, "C. protea" are perhaps C. nivea, as may be some of the specimens of 0. 

Patagonica : but, along with the last, are too much worn for certain identification. 

The following additional p::irticulars of Mr. Brooerip's species may also be use- 
ful to students. 

Galerus unguis is very small, conical, and dark coloured. G. eordidus appears 
a Hatter, lighter variety of the same species. Mr. Cuming's specimens are ail 
oovered with Bryozoa ; but none of them shew any tendency towards the corruga- 
ted exterior represented in the Trans. Zool. Soc. pi. 2S, f. 2. 

Galerus striatus is well distinguished by its strongly sculptured exterior. 

Orepidula marijinalii is intermediate in characters between C. onyx and C. 
aculeata; having the external appearance of the former, with a thin waved deck 
more resembling the latter. 

Orucibuhim serratum outside resembles Cr. ?? imbricatum vir. Cumingii: but 
within, it has a remarkably appressed and angular cup. It comes more close to 
Cr. pectiQatum, Proc. Zool. Soo, June, 1S56. 



MAZATLA-V UNIVALVES 293 

Crucibulum spinosiim begins life as a smooth. Velutina- 
shaped body, about "03 across, scarcely differing from tlie 
young of C. imbricatum. Sow. As it spreads out, it commences 
its cup as a Crepididoid deck, growing like that of Crepidula 
nivea, but at a greater angle. Tliis is soon developed into a 
semicircular lamina, much, flattened at the posterior end, and 
in the same proportion produced anteriorly. On the smooth 
surface are first developed fine stria; ; then rather irregular 
but fine corrugations, radiating to the margin as in Patella, 
not folloTsing the spiral grovrth of the shell. These corruga- 
tions are sometimes decussated by the lines of growth, which 
occasionally develop concentric lamina?, as in Crepidula Les- 
Bonii. Over these corrugations appear, not in the same 
direction, but in lines more or less spirally diagonal, and more 
or less irregular, either small tubercles, or very small tubular 
spines, generally open at the top, and, when close to the 
margin, at the bottom also. The spines are often very long, 
either on a portion or on the whole of the shell. Some- 
times a few rows are i)i'edominant, as in C. hystrix, Srod. -. 
sometimes all are alike and very crowded. In this state, 
the corrugations often disappear, developing themselves into 
spinous processes. It is common to find a shell smooth on the 
principal part, then suddenly developing spines at one corner ; 
or sometimes a shell, whicli was spiny in its earlier stage, goes 
on smooth. In shape there is the same diversity. Most of 
the young sliells are ratlicr conical : but they generally deve- 
lop in a more or less expanded form, sometimes nearly flat. 
Mr. Cuming has a most wonderful specimen (figured in the 
Tram. Zool. Soc. pi. 28, f. 8), which he extracted from a spheri- 
cal hole in a large stone brought up from deep water. After 
beginning in the usual conical way, it had spread out almost 
flat, the cup projecting far bej'ond the base of the shell, and 
the enormously large spines being recurved above the vertex. 
The life of this creature must have been perfectly sedentary. 
Other specimens however, after beginning with an uneven aud 
broken margin, appear to have gone in quest of more quiet. 
abodes, and have continued as flat and regular shells. The 
margin is either entire, slightly crenulatod by the corrugations, 
or beautifully indented and pierced by the tubes, according to 
circumstances. The cup is adherent for about two-thirds of 
its height ; very rarely to near the top, as in C. imbricatum. 
It is always flattened at the inner posterior portion, with a 
more or less defined angular groove, separating the flat from 
the swoUen portion. It is white, with transparent lines of 



294 MAZATIAN VNIVALVES 

ffroArtli in the lower part ; towards the apex stained with 
chesnut in the dark shells. The colour of the interior varies 
from pure suow w hite to very dark brown ; generally more or 
less spotted or rayed with chesnut. The finest specimens 
■were eagerly caught up by collectors : the largest I could 
find measures lo^ig. 1"72, lat.l'b, alt.'QS. 

Aflatsp. „ 1-3, „ 1-13, „ -27. 

Sab. — (C. tenuis) Samanco Bay, Peru ; on living shells, in mud- 
dy sand, 9 fm. ; Cuming. — (C. hispida) Isl. ]\ruerte ; on dead 
shells, in sandy mud, 12 fm. ; Cuming. — C. maculata) Do. 
11 fm. Cuming. — Panama ; under stones at low water mark, 
rare ; C. B. Adams. — San Diego, Lieut. Green. — Monterey ; 
very rare ; Nuttall. — Mazatlan ; not uncommon ; IS pool Col. 

Tablet 14-15 contains 3 sp. extremely young. — 1446, 3 do. a 
stage older.— 1447, 4 do. adolescent : on one a young Crepidula 
aculeata has fastened itself, wearing away the spines. — 1448, 
1 sp. adult, with attachment of another. 

Specimens sheioing form. Tablet 1449 contains a series of 9 
pp. from very flat to conical. — 1450, 3 sp. shewing crenations of 
the margin. — 1451, 4 do. margin very irregular. — 1452, 4 sp. 
ciiriously deformed and thickened by disease . 

Specimens shewing changes of surface. Tablet 1453 contains 
3 sp. nearly smooth. — 1454, 4 do. tubercular spines develop- 
ing. — 1455, 4 do. spines regular and crowded. — 1456, 6 sp. some 
spines greatly developed. 

Specimens shewing colour. Tablet 1457 contains 4 sp. white, 
developing chesnut rays. — 1458, 5 do. light brown, scarcely or 
generally diffused. — 1459, 4 do. tortoiseshell pattern. — 1460, 4 
do. tortoiseshell changing into dark brown. 



Gbnus CALYPTEyEA, Lam. 

Calyptrsea auct. (pars.) Subgen. Calyptrsea, b. Less. Brod. 
Calyptra, Humph. 1797, (pars). Grai/, Proc. Zool. Soc. 1847, 

p. 157, no. 271.— -ST. ^- A. Ad. Gen.\. 364. 
?-litrularia, Schum-. 1817, Ess. no. 9.— Phil. Sandb. Conch. 

p. 186. 
Lithedaphus, Owen, Proc. Zool. Soc. 1842, p. 147.— Litholepas, 

Gray, loc. cit. 
Cemoria, Hisso, 4826 ; non Leach, nee Swains. 



MAZATLAN TINIVALVES 295 

This group, first distinguislied by Sckum., is characterized 
by its free, semi-tubular lamina, like a cornucopia divided 
longitudinally. It may be regarded as a Crepidula with each 
marginal sinus intensified ; or as a Crucibulum with the lamina 
free instead of being turned round upon itself. A full descrip- 
tion of the animal of one species is given by Owen, loc. cit. It 
is probable that the young will be found to commence like 
Crepidula. The genus is represented in the Mazatlan collec- 
tion by a single specimen. In all the species examined, the 
plane of increase is more or less perpendicular to the base, aa 
in Capulus. The habit of growth is generally extremely 
irregular, as in Hipponyx, which at least some of the species 
resemble in possessing a shelly plate of adherence. As far as 
can be judged by the specimens in the Cumingian Museum, 
the species which Brod. has constituted in this group are all 
well founded. C. corrugata has an exterior like Crucibulum 
umbrella, Desk. ( = rudis, Brod.) The other three species dijQfer 
in the growth of the cup : that in C. cepacea is produced 
forward, and occupies not much more than a semicircle ; in 
C. varia, it grows straight up, occupying three-fourths of a 
circle ; in C. cornea, it is compressed, lengthened, with pro- 
jecting points, and the opening very small. 

345. Calyfte^a cepacea, Brod. 

Proc. Zool. Soc. 1834, p. 35 -.—Trans. Zool. Soc. vol. i. p. 197, 
pi. 27, f. 4,.— Mull. Si/ii. Nov. Test. Viv. p. U2.—Lam. An. s. 
Vert. vol. vii. p. 633, no. 21.— Rev. Zool. Cuv. Soc. July, 
1838.— CMnii, Lee. Mem. p. 144, f. ?4>Q2.—]\£ke. Zeit.f. Mai. 
1851, p. 36, no. 128.— C. B. Ad. Pan. Shells, p. 220, no. 332. 
This shell is easily distinguished from the W. Indian species, 
C. equestris, &c. both by the vertex and the markings. The 
nucleus consists of an elevated spiral body, like Bithinia. (The 
apex is unfortunately wanting.) The spire axis is fixed horizon- 
tally. The sculpture of the shell consists of extremely fine, 
close, radiating lines, which under the microscope are found 
to be sharp ridges, with semicircular spaces between, crowded 
with concentric (semicircular) striae. Long. "Si, lat. '65, alt. '23. 
Sah. — Isl. Muerte ; on dead shells, in sandy mud, 11 fm. ; 
Cuming. — Panama ; extremely rare, on dead shells, at low- 
water mark; C. B. Adams.— 'MdzoXlao., Menke : — one sp. 
L'pool Col. 

Tablet 14^1 contains the specimen. 



296 mazatlan univalves 

Family CAPULID^. 
Gekcs HIPPONYX, Defr. 

Cochlolepag, Klein. 1753 :— S". 8f A. Ad. Gen. vol. i. p. 373. 

(Non Conckolepas, Lam.) 

346. HlPPOUTX SESEATUS, n. s. 

H. t. conicd sen depressa, alba ; apice decollato, subcentrali 
sen valde remoto, intenlinTi valde prominente ; lamslUs crebris, 
acutis, extantihus, basi parallcUbus, concentrice ornatd ; apicem 
versus radiatim coatatX ; supra lamellas radiatim tcnuissime 
sulcata ; basi latissimd, planatd, lamelUs creherrimis instructd ; 
lamellis profande serratis, lobis subquadratis ; inter lamellas 
epidermide fused copiosissime indutd, tceniis incisis confertd ; 
cicatrice musculari transversim corrugatd. 
Proc. Zool. Soc. 1856, p. 3, no. 2. 
?= Hipponyx foliaceu3, Mice, in Zeit. f. Mai. 1851, p. 36, 

no. 129, non Quojj Sf Gaim. 

This well marked species differs from H. antiquata, Linn. 
in the character of the base, which is broad and flat, made up 
of very numerous, close-set lamella, deeply serrated into large 
scarcely rounded lobss. The interstices are filled with epider- 
mis, in irregular ribbaad-like shreds as in Byssoarca Pacifica. 
The exterior, which rarely displays its characters satisfactorily, 
has sliffht tubercular ribs near tlie apex, which are continued 
over the lamellae as very fine, rather distant, indented striae. 
The apex is sometimes flat, sometimes high and curved back 
as in Emarginula rosea. It is always decollated and eroded. 
One extremely young specimen has the minute helieoid apex 
adhering to the spreading, rounded shell. The shelly base is 
almost always very thin and smooth, sometimes scarcely per- 
ceptible. It is nearly related to an Australian species, probably 
H. foliaceus, Quoi/ ; but in that species the lamelhe are serrated 
outside with the strong radiating sulci ; the lobes of the basal 
laminae are more rounded; and the epidermis is finer and 
lighter. The largest specimen measures (from the very pro- 
jecting apex) long. '96, lat. '94, ait. '46. 

A very flat sp. „ -86, „ '78, „ -25. 

A very conical sp. „ *68, „ *73, „ "43. 

Hab. — Mazatlan ; gregarious, attached to each other, or on 

shells, (Byssoarcae, &c.) rare ; L'pool Col. 



MAZATLAN TTNITALVES 297 

Tablet 1462 contains an extremely J^oung sp. with, the helicoid 
apex. — 1463, 2 young sp., one on Byssoarca solida. — 14'64, 1 sp. 
with exterior beautifully perfect. — 1465, 2 sp. one very flat, 
the other very conical. — 1466, 2 distorted sp. of which one is 
shaped like Amathina, Grai/. — 1467, 1 sp. probably old, with 
the margin narrowed inside by non-serrated lamina?. — 1468, 
3 sp. shewLog basal supports on the outside. 



347. HippoNYX AXTiQUATUS, Linn. 

Patella antiquata, Linn. Si/st. Nat. p. 1259. — Gmel. p. 3709.— 

Mont. Test. Brit. p. 485, pi. 13. f. 9.—DiUiv. Descr. Cat. 

p. 1035, no. 44. 
=Lepas alba, Mart. Conch, pi. 12, f. 111-2. 
+ Patella Mitrula, Gmel. p. 3708. 
+ Patella nivea, Gmei. p. 3727. 
Le Soron, Adams. Sen. p. 32, pi. 2, f. 3. 

Pileopsis antiquata, Forbes Sf Hani. Br. Moll. vol. ii. p. 462. 
Hipponyx antiquatus, Mke. in Zeit.f. Mai. 1853, p. 79. — Proc. 

Zool. Soc. Jan, 1856, p. 3. 
Coehlolepas antiquatus, H. Sf A. Ad. Gen. i. 373. 
= Pileopsis mitrula, Lam. An. s. Vert. vol. vii. p. 610, no. 2. 
Capulus mitrula. Dank. Ic. Moll. Guin. p. 36, no. 99. — B. M. 

Cat. Cuba Moll. p. 32, no. 390. 
Hipponice mitrale, Defr. Journ. Bliys. 1819, f. 4. — Blainv. 

Malac. pi. 50, f. 4. 
Hipponyx mitrula, Sow. Proc. Zool. Soc. 1835, p. 5 : — do. Thes. 

Conch, (inter Brachiopoda, Nov. 1816) p. 369. no. 2, pi. 73, 

f. 18—20. 
Hipponyx Panamensis, C. B. Ad. Pan. Shells, p. 218, no. 328. 
Amalthea Panamensis, H. 8f A. Ad. Gen i. 374. 

Known from H. serratus by the rounded base. Sowerby'a 
species was described, as of Lam. from Peruvian shells brought 
by Mr. Cuming. Prof. Adams, finding certain differences of 
form and markings between his Panama and Caribbean speci- 
mens, gave the Pacific shells a fresh name. Both these and 
the Atlantic forms are however extremely variable in shape 
and details of sculpture.— Only three Mazatlan shells are 
referable to this spocies ; one, although only " 062 long, has its 
apex decollated, is compressed and conical, with the beak 
much recurved, and has very fine, close, radiating stria?, inter- 
rupted by lines of gi-owth ; the second, flattened and extremely 
worn, is curiously indented in the region of the head ; the 



298 MAZATLAN ITKIVALTES 

third, in fresh condition, is immature, with the apex but slight- 
ly recurved, and the radiating striae very coarse, while the 
concentric laminae are but slightly developed. Epidermis in 
shaggy layers between the laminae. Long. '34, lat. '3, alt. "18. 
Hah. — W. Indies, passim. — Cuba, Sagra. — Barbadoes, Br. 
Cutting. — Senegal, Adanson. — Loander, Tarns. — St. Vincent, 
W.Africa, Schmidt. — Lobos Is., Peru; on stones, among 
coarse sand, 17 ftn. ; Cuming. — Panama ; 14 sp. on stones 
and shells near low water mark, with thin attached valves ; 
C. B. Adams. — !Mazatlan ; extremely rare, off Spondylus ; 
L'pool Col. 

Tablet 1469 contains the 3 specimens. 

348, HiPPOJfTX PLANATUS, n. s. 

S. t. valde planatd, suhovali, albd ; vertice anfr. ii. rapide 
aiigentihus, lateraliter incumhentihus, interdum persistente ; 
t.juniore sparsim radiatim costatd ; postea laminis concentricis 
a sulcis radiantihus indsntatis, ad marginem t. juniore profunde, 
t. aduUd vix serratis ; epidermide tenui, laminas intercalante ; 
intus valde politd, cicatr. muse, angustd, circulari, regiane 
capitis hiterruptd ; margine producto, simj^lici, intus rotundato, 
extus tenuissime serrato ; valvd inferiare tenui (t. juniore) 
multo minore, usque ad regionem cicatricis solum continud. 

Three very smaU specimens of this species were found in 
. the Spondylus washings ; but Mr. Darbishire was fortunate 
enough to find a beautiful young shell in a Lithodomus bur- 
row in situ ; too late for the list in the Proc. Zool. Soc. 
Afterwards some large adult upper valves were brought by 
Mr. Bridges. All agree in the extreme flatness, torque-shaped 
muscular scar, finely' cancellated laminre and rounded but 
spreading margin. The spiral apex, being recumbent and 
rather solid, has remained on two of the specimens, a very 
unusual thing in the genus. It is known from even the flattest 
specimens of H. antiquatus by the shape of the scar, spreading 
margin, recumbent apex, and sparse radiation of the earlier 
portion. The youngest shell is "07 across, with the Heiicoid 
whirls about '015 in diameter. The most pei'fect specimen in 
Mr. Cuming's collection (not the largest) measures long. "73, 
lat. -64, alt. "17. 
Hab. — Mazatlan ; on Spondj-lus. extremely rare ; L'pool Col. — 

Bay of Panama, T. Bridges, Mus. Cuming. 

Tablet 1470 contains the youngest and an adolescent sp. 



MAZATLAN UNIVALVES 299 

349. HiPPONTX BAEBATTJS, Sow. 

Froc. Zool. Soc. 1835, p. 5 : — Thes. Conch. (Bracliiopoda,) p. 369. 
pi. 73, f. 26, 27.— C. B. Ad. Pa,i. Shells, p. 217, no. 327.— 
Proc. Zool. Soc. 1850, p. 3, no. 3. 
? = Hipponyx australis, Mhe. in Zeit. f. Mai. 1847, p. 186, 
no. 38 : non H. australis, De*// . = Patella australis. Lam. 
Shell commencing as a lielicoid body with nearly two whirls ; 
apex more or less sunken ; smooth, with the lip entire as in 
Cyclostoma. It then spreads out, develops slight strise, and 
long star-like rows of hairs, the mouth expanding downwards 
as in Helix. The spiral part remains longer than in most 
Hipponices ; the shell also is elongated. A j'oung specimen 
had eaten its way into the shell of Murex princeps, without 
shelly attachment, as in Amalthea. No attachment was found 
with the adult shells, while in Mr. Cuming's specimens it is 
enormous. Shell when mature with close nodulous ribs, each 
armed with a row of bristly hairs. laner margin rounded, 
crenulated by the ribs outside. Colour white, more or lesi 
tinged with rufous brown Long. '65, lat. "54, alt. '22. 
Sab. — Coral reefs round Toobouai, Soc. Is. Ce«ffi/«f/.— Panama ; 
on stones and shells near low water mark, rare ; C. B. Ad- 
ams. — Mazatlan ; young rare, adult very rare, on Spondylus 
calcifer, &c. ; L'pool Col. 

Tablet 1471 contains 6 sp. extremely young, the smallest '02. 
across. — 1472, 5 sp. different ages. — 1473, 2 sp. jun. off Mure« 
princeps, very elongated form. 



350. HippoxYX (Amalthea) Geayanus, Mhe. 

Zeit.f. Mai. 1853, p. 115.— Proc. Zool. Soc. 1856, p. 4, no. 4. 

Hipponyx radiata, Gra//, Proc. Zool. Soc. 1835. — C. B. Ad. 
Pan. Shells, p. 218, no.?,2d. — Mke. in Zeit.f. Mai. 1853, 
p. 79. (Non H. radiata, Quoy Sf Oaim. 1824 : nee H. radiata, 
Desh. 1830, in Lam. An. s. Vert. vol. vii. p. 616, no. 6; = 
H. crispa, Mke. loc. cit.) 

Only one small dead shell was found, which probably be- 
longs to this species. Although only "06 across, the apex is 
decollated. In well developed specimens, the ribs are fewer, 
coarser and more nodulous than in H. barbata. The epidermal 
hairs are softer, smaller, fewer, and ii-rcgularly scattered. The 
apex is subcentral. Base rounded within, flattened externally, 



300 MAZATLAN TJKIVALVE3 

where it is crenated by tlie ribs, with numerous lamellEB, 
undulated, not serrated. 

Sab. — Gallapagos, Cuming. — Sandwich Is. on Pinna, Nuttall. — 
Panama, 16 sp. on stones, near low water mark ; C. B. Ad- 
ams.—^. W. Mexico, on Pinna, P. P. C. — St. Vincent 
(Guinea) Schmidt, teste Menke. — Mazatlan ; extremely rare ; 
L'pool Col. 
Tablet 1474 contains the specimen. 



GENrs CAPULUS, Monif. 

Capulus, Conch. Syst. II. 54, 1810. — Phil. Handb. Conch. 

p. 188.—^. ^- A. Ad. Gen. i. 371. 
Pileopsis, Lam. Extr. Cours. 1812. 
Amalthea, pars, Schum. JSss, p. 181, 1817. 



351. Captjlus , sp. ind. 

Tablet 1475 contains 3 apical fragments which may be con- 
specific, though they differ somewhat in sculpture and outline. 
They appear nearly related to the W. Indian Patella militaris, 
Idnn. The vertex has two tumid helicoid whirls, of which the 
upper is prominent, in thi.s respect differing from the supposed 
young of Hipponyx serratus . 
JIab. — Mazatlan ; 3 sp. on Spondylus ; L'pool Col. 



Family VERMETID^. 

Neither animals, shells nor opercula in this family have yet 
been studied by travelers, as much as from their diversity and 
aberrant characters they deserve. The species are extremely 
difficult to discriminate by the shells alone. Habit of growth 
and colour appear to be of more consequence than the variable 
details of sculpture. The figures of Chenu and Valenciennes, 
unaccompanied by either description or geographical informa- 
tion, are ratlier calculated to confuse than to aid the student. 
Eemarkable variations were found among the opercula, which, 
from their occurring among the Spondylus washings, and from 
their not being ad.nissible in any other direction, appear to 
belong to this family : but only in regard to two species can 



MAZATLAN TTNITALTES 301 

they be deteiininately referred to the shells. The two are 
therefore described separately, leaving their union to future 
researches. The arrangement of generic sections is simply 
provisional. 

Genus SIPHONIUM, Browne. ■ 

Testa valde irregularis, juniore haud turritelloidea. Oper- 
culum tenue, concavum, haud laminatum. 

Section A. Species typici. 

Operculo valde co?icavo, vix spirali. Species oceanis Ailantico 
tt Orieydalihus repertce. 

B. Subgenus ALETES. 

Opei'culo parum concavo, multispiraU, scepe irregulariter 
formatum. 

It might have been thought that the turritelloid opercula 
would have belonged to the turritelloid shells. Such however 
is not found to be the case ; the opercula of V. lunibricalis, 
Hindsii, &c. being formed on the laminated type, with a very 
large outer whirl. Without a knowledge of the animals or the 
opercula, these shells can hardly be separated even specifically 
from those of Siphonium proper and Serpulorbis. 

352, Aletes centiquadeus, Val. 

A. t. magna, pallide, interdum intcnsius rvfo-fuscd ; anfr. 
nucleosis parvis, lavihus, globosis, spird vix monstrante ; deiit 
anfr. rapide augcntibus, separatis ; interdum irregulariter 
spiralihus, ad ang. 25", interdv^m varie contortis ; seu segregatis, 
seu glomeratis ; conchis et rupihus parum affixa,facile se2)aratd, ; 
superjicie plerumque spiraUter dense rugosCi, lineis incrementi 
transversis decussantibus, interstitiis subprofunde punctatis : 
pagind omnino inferiore et interdum, testa adultd, totd superjicie 
srulpturd obsoletd ; hasi interdum planatd, angulatd ; transver- 
sim interdum septo concavo divisd. 

Operculo parvo, dimidio apertures cequante ; extus concavo ; 
in medio Imviore, strudurd vix conspicud, apice planato ; margi- 
nem versus multispiraU, margiiiibus anfractuum haud plurimo- 
Aug. 1856. cc 



•302 MAZATLAN UNIVAIVES 

rum Icevibus, parum elevatis, hand (normalitei') separatis : intus 
convexiore, cicatr. muse, medlano, circulari, macjna, irregulariter 
conceiitrlce rugtilosd ; rnarcjinem versus anfractus monstrante. 
Verraetus centiquadrus, Yal. Voj/. Ven. pi. 11, f. 1, \a, la his. 
+ Vermetus Peronii, Yal. loc. cit. f. 3, 3a. 

The operculum appears intermediate in character between 
the regularly multispiral operculum supposed to belong to a 
species of this group, and the deeply concave, paucispiral 
operculum of Siphouium giganteum. One specimen foimd in 
situ, (by which, along with two others scarcely admitting of 
doubt, the rest were identified,) has not more than half the 
diameter of the aperture. ]\Iost of the few found were more 
or less irregular ; the edges having a tendency to separate 
elevation, and the whirls to become fewer after fracture. 

The V. Peronii, a group of which is figured on Strombus 
galea, fixing the locality of the si^ecies, appears only to differ 
from V. centiquadrus in the absence of punctures : but as both 
states are frequently found on the same specimen, it cannot 
warrant specific separation. 

The shell is loosely adhering, and of very irregular habit of 
growth: when spiral, with rapidly diverging whirls. The 
sculpture is close, and seldom much impressed. The colour is 
laid on here and there in blushes. An average specimen 
measures as it stands lo7ig. 2 '4, lat. 1"4, diam. '44. 
JSah. — Mazatlan ; not uncommon on Spondylus and Chama ; 

also on stones and other shells ; L'pool Sf Havre Coll. 

Tablet 1476 contains an extremely j'oung sp. with apex en- 
veloped ; also one somewhat older. — 1477, a yoiing sp. growing 
straight, on Conns gladiator. — 1478, an adolescent sp. covering 
an extremely deformed Crepidula aculeata. On the back are 
some egg-cases, and on the same tablet a similar group. — 1479, 
2 sp. intertwined with spiral growth ; also a fragment shewing 
septa. — 1480, a sp. on Vitularia salebrosa. On reaching the 
canal, it has left its mouth, and twisted back at right angles. — 
1481, a specimen on rock, gi'ovviug upwards, spirally twisted on 
itself. — 1482, a large group off Spondylus, with Petaloconchus, 
Annelids, &c. — 1483, an operculum as found in a fragment of 
the shell ; also 4 separate opercula, of which 3 arc abnormal. 

352 b. Aletes ? centiquadexjs, var. imbeicattts. 

A. t. "A. cenfiquadro " simili, sed colore inteihriore ; rvgulis 
spiralibus parvis, confertissimis, kaud decussatis, squamulis 



MAZATLAN TJjTIVALVES 303 

arcuatis ornatis ; decumbente, vix spirali, pertvnaciter c^ffixd, 
superjiciem matricis partem erodente. 

Only one characteristic and one rubbed specimen were found 
of tkis shell, which, may be a Spiroglyphus. It has however 
some characters in common with the young of the great Cali- 
fornian Vermetid, Aletes squamigerus. Long. '6, lat. apert. *13. 
Sab. — Mazatlan ; extremely rare, on Uvanilla an^ Cuma ; 

Upool Col. 

Tablet 1484 contains the characteristic sp. 

353. Aletes MARQAEiTAKrM, Val. 

A. t. "A. centiquadro" simili, sed anfr. nucleosis iii. magis 
elorif/atis ; anfr. normalihus rapide augentibus ; adidta suh- 
quad'rata, ad angulas carinis nodosis conspicue ornatd ; liris 
tenuioribus, vix deciissatls. 
Vermetus margaritarimi, Val. Voy. Yen. pi. 11, f. 2. 

Only one adult and two extremely young sp. were found, 
which may not be conspecific. The nuclear whirls are not 
globular, as appears the case in the only specimen seen of V. 
centiquadrus ; in this respect it is intermediate between that 
species and Bivonia. Long. I'l lat. apert. '3. 
Sab. — Mazatlan : extremely rare, on Spondylus ; L'pool Col. 

Tablet 1485 contains the youngest and the adult specimen. 



Genus VEEItlETUS, Adanson. 

Testa plus minusve spiralis. Ojjerculwn magnum ; extus 
laminis concentricisfoliaceis instructum : intus marginem versv-s 
convexum ; cicatrice musculan circulari, concentrice ccelatd. 
Sen. p. 160, 1757.— JT. ^- A. Ad. Gen. vol. i. p. 357. 

Section A. Species typici. 

Testdjtmiore turritelloided. Operculo colore corneo, tenuiore, 
extus foliaceo ; cicatrice concentrice lirulatu. 

The turriteUoid Vermetidse form a small but natural group ; 
of which the species are distinguished by the sculpture of the 
spiral portion, and of the operculum. 



304 MAZATLAN T7XIVALTE8 

354. Veemetps ebueneus, Rve. 

V. t. alba, seu ruhro-fusco tincta, satis magnd ; anfr. spirali- 
hus albis x.-xiv. ; primis iii. valde rotundatis, Icevibiis ; detn 
carina una acutd, dein duabus, postea tribus monstrantibus, 
quarum una circa peripheriam major ; postea subito irrcgulari, 
anfr. separatis, vix spiralibus, marginibus plerumque valde 
divergentibus, parum seu ad sese, sen ad concham alienam, 
ajjixis ; spiraliter tenue et confertim striata, costis interdum 
subobsoletis ; adultci interdum rufo-fusco tincta. 

Operculo extus concavo ; foliis plurimis tenuibus altera intus 
alteram sitd ; radiatim tenuissime striulato, striularum inter- 
stitiis punctulatis ; intus marginem versus convexo, opaciore, 
margine tenuissimo ; cicatrice circulari, trienti latitudinis haud 
(Equante, lirulis circiter xii. concentriris ornato. 
Proc. Zool. Soc. 1842, p. 1.97 ■.—Co7ick. S^st. vol. ii. p. 46, 

pi. 152, f. 2. 

Comp. Vermetus pellucidus, Brod. Sf Sow. Zool. Joum. vol. iv. 

1829, p. 369. " V. t.pellucidd, longitudinaliter striata, apicem 

versus carinatd." (This description will suit the young of 

V. eburneua, but is not sufficiently explicit for certainty.) 

The operculum is described from specimens in Mr. Cuming's 

collection, which are believed to be authentic, as they agree 

with that of V. Hmdsii in the B. M,, though differing essentially 

from the figure professing to be of that species in S. Sf A. Ad. 

Gen. pi. 88, f. 8, a, b. An operculum agreeing even in the 

peculiar microscopic markings is seen in Mus. Cum. in a very 

different shell, which has lost its apex, but is probably an 

Aletes, and s not unlike A. squamigerus. The V. Hindsii 

seems to diffeir from V. eburneus in the arrangement of the 

keels on the turritelloid portion. 

About 30 young specimens of this very beautiful species 
were obtained on Chamne and Spondyli ; but only two were 
found adult, loosely entwined on a Chama. These, having 
passed through the acid process, have lost their sculpture and 
would hardly be known from A. centiquadrus, (with which 
the later whirls agree in colour,) but for the Turritelloid 
apices, which have fortunately survived. The sudden contrast 
between the elegantly chiseled, alabastrine Pseudo-Turjitella, 
and the irregular, almost smooth subsequent whirls, is very 
remarkable. A fossil species found by Mr. Kuttall at New- 
bum, N. Carolina, differs essentially from the Atlantic species, 
and offers no marks by which it has been distingmshed from this. 



MAZATLAN UNIVALVES 305 

The longest spire measui-es '44, by '14; the adult, long. 1'9, 

diam. apert. "5. 

Hab. — Mazatlan ; extremely rare, on Chamac and Spondyli ; 

L'pool Col. 

Tablet 1486 contains 1 extremely young and 1 adult spire.— 
14S7, 2 sp. irregular portion commencing : one has cemented 
to itself the valve of a Donax.— 1488, the adult specimens, on 
Chama frondosa (Mexicana.) 

Section B. BIVONIA, Gray. 

Testa solute spiralis, nunquam turritelloidea : Operculo rubra, 
solidiore, extus parum foUaceo, intiis cicatrice corrugatd, ple- 
rumque vix concentrice Urulatd, scepe umhonata. 
(Diagn. carent.) Proc. Zool. Sac. 1847, p. 156, no. 258 -.—Fig. 

Moll. An. p. 82, no. 3; "operculum rudimentary, small. 

(Pspiral.)"— £". Sf A. Ad. Gen. vol. i. p. 358; "operculum 

red, convex in the middle, with a thin, flat margin, and a 

central muscular scar." 

The name is retained for the typical species quoted by Dr. 
G-ray in default of description. It was natural that Bivon and 
Philippi should not be agreed in their account of the oper- 
culum of V. glomeratus, Phil, as the concentric elements 
present a very spiral appearance, and the outside is almost 
always !incrusted with coralline &c. which, even if removed, 
probably carries off the foliated surface along with it. The 
genus, as afterwards defined by Dr. Gray, "operculum small, 
rudimentary," applies better to what little is known of Petalo- 
conchus, one species of which inhabits the Mediterranean. 

355. PBlVONIA CONTOETA, 71. S. 

?B. t. minore, ruhidd, caneellatd ; anfr. nucleosis iii. leevibus, 
elevatis ; normalibus irregulariter una super alio decliviter 
et spiraliter incumbentibus, marginibus scepe vix parallelis : 
plerumque solitarid, conchis variis basi iota tenue adkatrente ; 
sculpturd ut in A. centiquadro ; aperturd rotundatd. 
Comp. Verraetus glomeratus, Rouss. in Ch^nu III. Conch, pi. 2, 

f. 2 (1843).— 3//L-e. in Zcit. f. Mai. 18^17, p. 178, no. 4 :— do. 

1850, p. 165, no. 14.— C. B. Ad. Pan. Shells, p. 216, no. 323. 

Mab. — Panama ; attached by a small part of the spiral por- 



306 MAZATLAN UNIVALVES 

tion of tlie shells to rocks and stones, near low water mark 

of neap tides, not uncommon ; C. B. Adams. 
Comp. Vermetus Pauameusis, " Rouss. in Chenu, HI. Conch. 

pi. 5, f. l."—Mke. in Zeit. f. Mai. 1850, p. 165, no. 13.— 

C. B. Ad. Pan. Shells, p. 216. no. 3'21. jK^S.— Mazatlan ; 

in mass of coral, on Spondylus ; Menlce. — Panama ; in the 

same situations as V. glomeratus, attached on one side of all 

the whirls ; C. B. Adams. 

This species may possibly be the V. glomeratus of Mice, and 
C. B. Ad. : but as it is not the S. glomerata of Linn. (v. Sanl. 
Ips. Linn. Conch, p. 441,) nor the V. glomeratus of Phil., which 
has a peculiar habit of growth, it does not seem fair to adopt 
the name figured ouly in Chenu, especially as that appears a 
third species, judging by the size and colour.* — The shell may 
again prove to be the V. Panamensis of the same authors ; but 
the figures cited do not -appear with that name, but with that 
of V. lumbricaUs, Lam. There can scarcelj' be a doubt that 
they represent the species of Adanson "Le Vermet" : as to 
whether that be the real V. lumbricalis o{ Lam., v. Desh. An. s. 
Vert. vol. ix. p. 66, no. 1. "UTiether this again be the S. him- 
bricalis o? Linn., v. Hani. Lps. Linn. Conch, p. 445. 

The shell is much more uniform in diameter and more parallel 
in spire-margins than A. centiquadrus, jun. which it resembles 
in sculpture, and mode of attachment. The colour is however 
generally with more of a pink and less of a brown tinge. The 
nuclear whii'ls resemble Rissoa. It is known externally from 
Petaloconchus macrophragma, which it resembles in mode of 
gn'owth, bj- its much ligher coloiu', without purple tinge. An 
extremely fine specimen, from the Gulf of California, is in 
Mr. Cuming's collection. A closely related, if not identical 
species is found in the W. Indies. Long. '9, lat. apert. '14. 
Sab. — Mazatlan ; not uncommon, on Spondylus, Gadinia, and 

other shells ; L'pool Col. 

Tablet 1489 contains 4 sp. very young.— 1490, 1 sp. on frag- 
ment of Pinna, and several young on Gadinia pcntegonio- 

* Or C. B. Adams' V. glomeratns may be the Aletes centiquadrus, which is 
cited under query in the Fan. ShelU as a synonym. A different species from 
either, though intermediate in character, was brought from Panama by Mr. 
Bridges, and may be the V. Panamensis. ? Has Prof. Adams in this eenus alone 
taken his synouynis on trust, and copied the species of Meuke's Catalogue. This 
at least will explain the confusion. Mr. Bridges' shell was at first believed by 
Mr. Cuming and myself to be a Petaloconchus, in consequence of the edges of a 
minute Isognomon appearing inside a broken section. After openin" several parts 
in hopes of observing the structure, the bivalve fell out, and .the Vermetid sub- 
sided into Bivouia, 



MAZATLAN UNIVALVES 307 

stoma.— 1491, 1 sp. on fragment of Spondylus, with Bryozoa, 
&c.— 1493, 1 sp. on Uvanilla unguis.— 1493, 2 separate sp., of 
which one has deep sculpture. 



355 6. PBlVONIA PCONTOETA, VaV. INDENTATA. 

B. t. "B. contortcB " simili, sed mimre ; colore hand rosea ; 
sculpturd indentata ; costis pauciorihus ; interstitiis profundis, 
caneellatis. 

This form would hardly be distinguished as a species from 
the shell alone, so variable is the sculpture of Vermetidae, 
even on the same specimen ; but as it is not improbable that 
the second Bivonoid operculum, which is quite distinct, be- 
longs to it, it is here kept provisionally separate. It is of 
smaller growth, and yet of much coarser sculpture ; with a 
different shade of colour, which in this family appears to be of 
some importance. Long. "5, diam. apert. 'Oh. 
Hah. — Mazatlan ; very rare, on Spondyh &c ; L'pool Col. 

Tablet 1494 contains 3 specimens. 



356 PBlVOKIA ALBIDA, «. S. 

B. t. parvd, alhida ; ahfr. ii. primis lavibus, turbinoideis, 
suhelevatis, postea amplectatis ; anfr. normalibus suhregulanter 
spiraliter contortis, marginihus suhparallelifi, ad sese plerumque, 
ad concham alienam parum, adhareniibus ; riigis concentricis 
plus minusve exjjressis, spiralibus nullis. 

Both sculpture, colour and size mark this species as distinct, 
although only 2 extremely young specimens and one with 
about 5 normal whirls were found. This measures long. "22, 
lat. "1, diam. apert. '03. 
.Hizi.— Mazatlan : extremely rare, off Spondylus ; L'pool Col. 

Tablet 1495 contains a young and the adult specimen. 



357. PBiVONiA , sp. ind. (a.) 

Tablet 1496 contains 2 minute Spirorbiform specimens, and a 
portion of a separate non-spiral tube, only '02 in diameter, 
which do not appear to be the young of any of the former 
species. They are of a pale colour, and are nearly smooth. 



308 MAZATLAN UNIVALVES 

Tablet 1497 contains a sp. "08 across, on Pisania insignia, 
containing 4 regular sinistral wkiils, like Planorbis spirorbis. 
It is sniooth, and may be the same species as the above, the 
diameter being about the same ; but the colour is much deeper. 
Sab. — Mazatlan ; extremely rare ; ISiwol Col. 



358. P? BivoNiA , sp. ind. (h.) 

Tablet 1498 contains a scarcely spiral white shell wandering 
like an Annelid over a Byssoarca solida. The texture however 
appears Molluscan. It has two very stout rounded keels on 
the back. The same sp. displays the attached valve of Hip- 
ponyx serratus. 
Sab. — Mazatlan ; extremely rare ; L'pool Col. 



Genus PETALOCONCHUS, Lea. 

Animal ignotum. 

Testa extus "Bivonice" simUUma ; intus, transversim raris- 
sime septata ; anfractihiis medianis, laminis elongatis spiralibtcs 
varie dispositis, cameram scepe pcene secantihus ; 2^i^f^^i^^ 
duabus majorihus, tertid, quasi plica. columellari, minore. 

Operculum [specierum duaruni] parvum, tenuissimum, corne- 
um, Iceve, subplanatum, vix spirale. 
m C. Lea, Trans. Am. Phil. Soc. 1843, vol. ix. p. 229.— Woodw. 

Man. Moll. pt. 3, p. 462. — Monogr. in Proc. Zool. Soc. 

July, 1856. 

The remarkable internal structiire in many species ofVer- 
metidae, appears to have been overlooked by English naturalists, 
although it was observed mauj" years ago by Lea in a fossil 
species. Three species in my collection from different scaa 
having presented clear difference of external structure, I had 
proposed for them the name of Maerophragma, which is now 
retained for the typical, though small, Mazatlan species. Mr. 
Cuming having most obligingly allowed me to open several of 
his specimens, nine species have been found, which are des- 
cribed in the Proc. Zool. Soc. They cannot be distinguished 
externally from Bivonia, which even as species they most 
closely resemble. The shell has somewhat the same relation 
to VermetuB that Nerina^a has to Cerithiiun. 



MAZATLAN UNIVALVES 309 

359. Petaloconchtjs maceopheagma, n. s. 

p. t. parvd, dextrali, dense purpureo-fuscA ; cylindraced, 
solute spirali, marginibus spires scepe suhparallelis ; plerumque 
glomerante, interdum soUtarid ; basi ad conchas, seu altera ad 
alteram, constricte adhcerente, sa;pe erodente ; superficie rugis 
irregidaribus spiralibus haud extantibus, et riigulis incrementi 
ornatd : intus anfr. primis, et itltimis quoad iv., apertis; medlanis 
lamiitatis ; lamina superiore multo majore, prius conspicud, a 
colu)?ielld extante ; primum simpUci, dein angulo recto rejiexd, 
extus carinis i-iii. quarum ii. acutissimis ; lamind inferiore 
simplici, a columella extante, altero juxta carinam fere attin- 
gente ; lamind tertid minima, intercalante, hrferiori pcene attin- 
gente ; laminis tenuissimis, albis, diaphanis, lineis incrementi 
conspicuis ; pagind interna niaxime nitente, transversim haud 
septato. 

The shell is of small diameter ; when growing freely taking 
a tolerably regular spiral, like a Turritella squeezed sideways ; 
the whirls enlarging very slowly, and resembling a winding 
staircase. It is known when fresh by its lustrous j)urple-bro\vn 
colour and absence of pits on the surface. It occasionally eats 
into the shell on which it grows, like Spiroglyphus, from 
which it is known by being dextral and cylindrical. Sometimes 
it clusters in large masses, like Bivonia glomerata. At which 
whirl the internal lamina? commence, it is difficult to say ; they 
have been counted running through 10 whirls ; and the terminal 
number of open whirls appears to vary. At each end they 
commence (the large upper one first) as simple columellar 
plaits, afterwards increasing till thej^ fill the greater part of the 
cavity and nearly meet. The upper one bends at right angles, 
with two sharp keels at the corners, and a third, not always 
developed on the upper side. The lower one goes to meet it, 
forming with it and the columella a rectangle, only com- 
municating with the remainder by a narrow slit. A small 
columellar plait supports the inside base of the lower lamina. 
The delicate texture of these laminne resembles the cup in 
Crucibulum, &c. No transverse i)artitions have been seen. A 
solitary specimen on the base of a Uvanilla unguis has at least 
13 whirls, and measures long. "05, lat. "13, div. 6". A large 
sp. measures lat. "23, diam. apert. "07. 
Hab. — Mazatlan ; not uncommon, on Uvanilla, Cuma, Murei 

princeps, &c. ; L'pool Sf Havre Co^/.— Panama ; on Margari- 

tiphora; Mus. Cuming. 



310 MAZATIAN TTNITALVE3 

Tablet 1499 contains 6 sp. broken so as to shew tke internal 
lamin£&. — 1500, a mass almost covering Murex princeps, ivitli a 
? Sphaenia in a rarical foliation. — 1501, TJvaniUa olivacea, with 
several specimens attached. — 1502, 2 sp. of U. ungtiis, do. — 
1503, Leucozonia cingiilata, do. — 1504, 3 sp. Cnma costata, do. : 
in one, the P. macrophragma has been removed, shewing the 
amount of erosion. — 1505, Ehizocheilus nux. Pisania gemmata, 
and Columbella fusca, do. — 1506, Omphalius ligulatus and 
FissureUa rugosa, do. 

Opercula of Vermetida. 

(a.) Operculum o. " AletcR centiquadrcB" simile, sed magis 
regulariter multispirale ; extiis parum concavum, marginihus 
anfractuum Icevibus, parum extantihus, wmhone centrali elevata ; 
superjicie anfr. circiter viii., umbone iv. instructis ; intus cica- 
trice magna irregulariter concentrice rugosa. 

Tablet 1507 contains one of three opercula, probably belong- 
ing to a second species of Aletes. 

(h.) Operculum spirale, corneum, suhoUvaceum, tenue ; exfu^ 
parum concavum, marginihus valde tenuibus, haud regularihus ; 
anfr. circiter ixv. haud distincte definitis, haud extantihus, ad 
apicem haud umbonatum ascendentibus ; intus cicatrice parvo, 
vix corrugafo. 

Tablet 1508 contains two opercvda, which probably belong 
to an Aletes. 

(c.J Operculum haudparvum, haud regulare, corneum, tenue, 
diaphanum ; extus subconcavum, laminis parum elevatis, um- 
bone extante : intus vix convexum, liris /concentricis multis 
subdistantihus, subextantibus, margine parvo ; cicatrice parvd, 
irregularite}^ concentrice rugosa. 

Tablet 1509 contains an operculum, in poor condition, inter- 
mediate between Alotcs and Vermetus proper ; remarkable 
for the internal ridges, which are not crowded into the middle 
portion, and leave a comparatively small margin. 

(d.) Operculum distincte spirale, tenue, corneum, diaphanum^ ; 
extus marginihus parum eonvexis ; lamina concavd solutd, kevi, 
acutd, spirahter ascendente, anfr. internis conveniente, apice 
parum elevato, vix umbonato : intus parum convexnm, trienie 
inteimd anfr. muUis ; trientibus duabus externis anfractu ultimo 
occupatis ; cicatrice vix corrugatd. 



MAZATLAN tJNIVALVES 311 

The outside presents the appearance of a set of saucers, but 
is more distinctly spiral even than in Aletes. When viewed 
inside by transmitted light, the size of the last whirl is not 
seen, owing to the intercalation of the external ridges. 

Tablet 1510 contains the only specimen found. 

(e.) Operculum minimum, corneuiu, tenne, jiavidMm, diapha- 
nuvi ; extus margiiiihus convexis, lamlnis concavis solute axim 
extantem concentrice, subspiralitei' ascendentibus, haudfoliaceis, 
suhcremilatis ; intus marcjinem versus convexum ; cicatrice 
parvd, circulari, lirulis extantibus concentricis circiter xii. 

One imperfect specimen alone was foimd. It most resembled 
Vermetus proper. The ridges appeared principally concentric, 
but here and there running into each other, as though spiraUy. 
The tiny saucers were piled on each other outside, so that the 
external outhne was convex. After repeated examinations, it 
sprang from the forceps, and was lost in the meshes of the 
carpet. 

Tablet 1511 contains a sketch. 

(f.) Operculum tenue, rubra - aurantium, haud regulare ; 
extus (plerumque dense incrustata) concavum, maxime intus 
umbonem, marr/inibus concentricis irregulariter vix extantibus ; 
intus lineis concentricis pluribus vix conspicuis ; umbone latiore, 
valde extante ; margine lata, corneo, plus minusve convexo ; 
muse, cicatr. circulari, 'pnrtem interioretn occupante. 

Six opercula were found, probably belonging to Bivonia 
contorta, whose reddish orange colour is cousijicuous against 
the verj' thick coralliuous incrustations which generally cover 
the outer part. The growth is irregular, but slightly concave 
externally, except inside the boss where it is very dpep. The 
margin is also irregular, and of a light horn colour. It closely 
resembles the opercidum of Bivonia glomerata, Phil., wliich is 
generally similarly incrusted. 

Tablet 1512 contains 2 opercula, shewing variations in gi'owth, 
\\ ith the thick incrustation removed from one of them. 

(g.) Operculum solidius, dense rufo-purpuretim ; extus con- 
vexum, marginibus foliaceis tenuibus, angulofere recto extanti- 
bus : intus concavum ; margine haud interrupto, valde rotunda to, 
convexo, angustiore, diaphand ; cicatr. muse, haud couspicue 
definita, lirulis concentricis viii. conspicuis ; umbone maxima 
extante, subspirali. 



312 MAZATLAN UNIVALVES 

This operculum within looks like a purple basin with a thin, 
narrow, transparent rounded edge, and a stout boss rising up 
in the middle. The outside, which was much incrusted, has 
the layers rising sharply from the surface up the spire. The 
concentric lirulse are distinctly marked within (except on the 
boss) with a conspicuous termination, but the margin shews no 
break. The colour near the boss is extremely deep. It is 
clearly congeneric but not conspecific with the last. 

Tablet 1513 contains the only specimen found. 

Family CyECID^. 

These creatures, ranked by Fleming among the Foraminifera, 
by Philippl (a prima manu) among the Pteropods, and after- 
wards, along with the Vermetidse between Eulima and Siph- 
onaria, are arranged by Gray between Eissoa and jMelania. 
Their natural allocation however appears to be between Ver- 
metus and Turritella, as assigned by Forhes Sf Hanley (Br. 
Moll. iii. 176) and by Clark (Moll. Test. Mar. Brit. p. 322.) 
They yet seem sufficiently distinct both in animal and shell, to 
be separated, as a family, from each of their congeners, 

Gefus C^CUM, Flem. 

Ccecum, Flem. 1824, Edinh. Fncycl. vol. vii. p. 67, et auct. 
Brochus + PCornuoides, Broion, 1827, Conch. Gr. Br. pp. 12^1, 125. 
Odontina, Zhorzewski, 1834), Mem. Sac. Mosc. iii. p. 310. 
Odontidium, Phil. 1836, Fmim. Moll. Sic. vol. i. p. 102. 
Caecalium, Macqil. 18443, Moll. Aherd. 
Cfficum, Phil. Ilandh. Conch, p. 197 :— iZ". Sf A. Ad. Gen. I 

355 : — Clark, loc. cit. 
Dentaliopsis, Clark, ms. 1834. 
Corniculina, Mimster. 
Odontostoma, Cantr. non Phil. 

For a fiUl account of the animals of the British species, 
V. Clark loc. cit. to whose patient researches, long hidden 
from the world, is due the first clearing of the mystery attend- 
ing these curious little shells. The animal of the N. England 
species, C. pulchellum, has also been described by Stimpson, 
Proc. Bost. Soc. N. II. Oct. 1851. With regard to the shells, 
errors have arisen from supposing that the adult form generall}- 
seen immediately follows the spiral part known to be the early 
stage of C. glabrum, and therefore believed to be characteristic 



MAZiTLAN UNIVAIiVES 313 

of the genus * Clark however speaks of three or four epochs 
of growth iu C. trachea, aud Stimpsou of two (with one inter- 
mediate) in C. puk-hellum. The large uumher of specimens that 
were fortunately disentombed from the worm-eaten galleries of 
Spoudyli and the crevices of Chama) and Ostrea), lead to the 
conclusion that some species at least form many successive 
portions ; so that if the whole shell could remain entire, an 
object would be seen resembling an mcurved Toxoceras, with 
a Skencoid apex. Among the 700 Mazatlan Caca of various 
ages, onlj'- one specimen with the spiral portion was found ; and 
not one of the spire alone. (The minute Vitriuells are perfectly 
distinct.) They ai-e probably so frail as rapidly to perish. 
After repeated examinations of large numbers of individuals, it 
is more easy to say what does not, tlian what does hold good as 
a specific character. The shell, at different iieriods of its growth, 
assumes very variable proportions of length and breadth, 
larger or smaller ares of circles with changeable radii, different 
forms of mouth, greater or less protrusion of apical plug, and 
perhaps opposite styles of sculpture. The different conditions 
are proved to belong to the same species bj- our continually 
finding sheUs with the anterior and posterior portions belong- 
ing to different types. Shells in this state were described by 
Prof. Adams as C. monstrosum, and must have been very 
puzzling to an author who in so variable a genus described 5 out 
of 8 species from 8 specimens. The number and disposition of 
the rings, on which several species are founded, is a very vari- 
able character. Perhaps the most constant is the form (not 
the amount of protrusion) of the apical plug ; which Prof. 
Adams, with less than his usual minuteness of description, un- 
fortunately passed over, although Searles Wood in his Crag 
Mollusca had called attention to its importance. A careful 
examination however of the tyges of 6 out of the 8 species 
described from Panama, which are fortunately preserved in 
the Cumingian collection, has supplied the deficient informa- 
tion. It seems ungracious, while now describing 16 new 
species from Mazatlan, (the oporcula being known in nine) to 
group together 5 out of the 8 already described from the same 
coast. I have only done so, because the necessities of the shells 
seemed to require it ; and it would have been easy, on the 
principles followed by Prof. Adams, to have increased the 
number of Mazatlan species four-fold. The plan here adopted 

• . . . " septum, marking the point at which the original spire has been 
cast off." Forbes Jf Hani, loc. cit. p. 170. 

Aug. 1856. dd 



314 MAZATLAK US^IVALVES 

was to take first tliose species (C. undatum and C. Iseve) of 
■which there were the greatest number of specimens presenting 
well marked characters ; to ascertain the mode of growth and 
power of variation in these ; then to apply principles so arrived 
at to the elucidation of the rarer forms. 

To save labour in the identification of species, they are here 
gi'ouped under 3 sections, according to form and sculpture. 
The plug also is described as either (1) mammillate, when it is 
uniformly convex, without apex, as in C. glabrum ; (2) ungu- 
late, when the whole sm-face gradually rises towards the back, 
where it ends in a long but narrow apex, as in C. trachea, 
presenting in profile the appearance of a hoof projecting from 
the ankle of the shell ; or (3) mucronate, when it is nearly 
flat over the principal part of the sui-face, rising suddenly into 
a knob at the back. The projectmg profile is described as 
"margo lateralis." 

The largest and finest shells belong to the group Elephantu- 
lum ; this is however scarce in individuals, and the tj-pical 
conition of the genus appears to be in the Anellum group.* 
Their relative proportion of individuals and species, as found 
in the Mazatlan collection, may be thus summed up. 

Elephantulum .... 5 species, 71 individuals. 

AneUum 6 „ 412 

Fartulum 7 „ 210 

Total 18 „ 693+ „ 



Section A. ELEPHANTtrLUJi. 

C. t. majore, tereti, solidiore, wctualiter arcuatd, aperturd vix 
contradd, postea expansd, parmn dedivi, adultd longitudin- 
aliter sulcata, testdjwniore hand suhiter mutante. 

The shells thus grouped are like minute Dcntalia Elephan- 
tina. They differ from the more common forms in their greater 
size and proportionate length, and in the regidarity of the 
outline, both when young and adult. They appear to be rare, 
both at Mazatlan and in other seas. Very few young speci- 
mens were found. From the appearance of the youngest, it is 
probable that those, like the annulate species, are smooth in 
the earhest stages. The number of ribs appears to be a very 

• Of a fourth jTonp. Inflatalum, only one species is yet known, recent in 
epongci, fossil »t Qrignon 



MAZATLAN XTNIVAIiVES 315 

inconstant cliaracter, as in Siphonaria. The liabit of growth 
also is very similar in all. Prof. Adams only found two specimens 
belonging to tliis group, which he called C. laqueatum ; the 
fortunate circumstance of one being in the Cumingian collec- 
tion enables us to complete the iinperfect description in Pan. 
SMls, no. 215, pp. 162, 311. The plug is found to be of unique 
formation, being mammUlate over the principal surface, with a 
separate rather prominent lateral tubercle, which is somewhat 
s nistral. 



360. C^CUM INSCULPTUM, 71. S. 

C. (Elephantulum) t.juniore vitred, diaphand, adultd solidd ; 
Uris validis quadratis et interstitiis profundis ornatd ; aper- 
tnram versus hand tmnente ; septo inigulato, suhprominente, 
apice obtiiso, paululum dextrorsum verso, marginc later alt sub- 
redo ; operculo ? . . . . 

Only one young and one adult specimen, besides fragments, 
were found of this species. The young shell is as transparent 
as glass, and of exqvusite beauty. The adidt is solid, beariag 
deeply cut sculpture. It is known from C. liratocinctum, by 
the absence of rings, the squareness of the ribs and depth of 
the interstices ; and by the plug which is somewhat interme- 
diate between the ungulate and mucronate forms, rising in a 
nearly straight and regular line to an obtuse apex which is 
turned somewhat to the side in both specimens. The young- 
est measures lo7ig. '053, lat. '013, — '017- 

The largest „ '133, ,, -023— -028. 

Sah. — Mazatlan ; extremely rare, off Spondylus, Upool Col. 

Tablet 1514 contains the perfect specimens, old and young. 



361. CiECtrM SUBSPIEALE, n. s. 

C. (Elephantulum) t. ma<rime elongatd, tenuissime liratd ; 
juxta aperiuram annulo suhtumente ; septo mucronato, super- 
ficie suhplanato, mucrone laterali, dextrorsum sita, parvd, apice 
rotundato, subspiraU : operculo concavo, tenui, anfr. plurimis 
lira tenui spiralitcr ascendente. 

Of this beautiful species, a giant among the Cseca, being no 
less than a tenth and a half of an inch in length, 6 perfect and 
6 broken sp. were found. It is known by the finely striated and 



316 MAZATLAN tTNITALVES 

slowly enlarging shell ; and by the plug, which is nearly flat, 
with a very small knob on the right side of the back. This, 
under a high power, appears to be of a subspiral growth, like 
a tiny Vitrinella fixed on the surface. The operculum appears 
to be thinner than that of C. liratocinctum, with rather more 
numerous whirls and a finer spiral ridge. It is known at once 
from the dextral specimens of that species by the very fine 
ribs being straight, never spii'al, and hy the apex being round, 
not pointed. 

The youngest specimen measures long. "05, lat. "007 — '01. 

The largest „ „ „ "loS, „ ■025— "OS. 

Sab. — Mazatlan ; ofi" Spondylus ; extremely rare ; I! pool Col. 

Tablet 1515 contains 2 very young specimens, the largest 
adult, and a fragment retaining its operculum. 



362. C^CUM ABNOEMALE, n. S. 

C. (Elephardulum) t. (lahnormaliier) curtissima, arcuata, 
latiore, tenuiore ; lirulis tenuissimis circiter xxx. ornatd, aper- 
turam varicosam tumentem supereuntibus ; interstitiis interdum 
minutissime concentrice striatis ; septo mucronato, prominente ; 
mucrone oninino dextrorsum lateraliter site, ohtusiore ; margine 
laterali (i. e. hoc specie, dorsali) concavo, rapide ascendente ; 
operculo ? . . , . 

Whether this be an extremely short deformed variety of 
C. subspirale, or a very aberrant species, cannot be affirmed 
until more specimens are found. It is common among Ca;ca, 
in the process of growth, for specimens of the same age to vary 
greatly in length ; but these shells, as shewn by the stout 
varix at the mouth, arc mature ; and yet, contrary to the habit 
of Elephantulum, they are much shorter in proportion even 
than in the compact group Inflatulum. They are so much 
bent that notwithstanding their shortness, both the surface of 
the plug and the interior of the mouth can be inspected with- 
out altering the position of the shell. Another very singular 
feature is the position of the plug, which is set on the extreme 
right, so that the front (or back) view of the shell gives it« 
profile. One specimen measures ZoM^y. "06, lat. '023; the other, 
loiig. -018, lat. "OlS. 
Sai). — Mazatlan ; 2 sp. ofi" Spondylus ; Z'pool Col. 

Tablet 1516 contains one specimen. 



MAZATLAN UNIVALVES 317 

363. Cjecum obtusttst, n. s. 

C (Elephantulum) t. elongatd, tenue Uratd,, aperturam ver- 
sus hand tumente, ; septo stihmammillato, parum tumente, apice 
obtusissimo dorstiin versus spectante ; operculo ? . . . . 

Six specimens and fragments were found of this species, 
which in. the liration closely resembles C liratocinctum, but 
appears quite destitute of rings. It is known however by the 
plug, which is almost mammillated, but has a very obtuse apex 
pointing towards the back. The smallest of the specimens 
measui'es long. '04, lat. '01 — '014. 

The largest „ -132, „ '017— -026. 

JIab. — Mazatlan ; extremely rare, off Spondylus ; L'pool Col. 

Tablet 1517 contains the largest and the smallest specimens. 

364. CiECtTM LIRATOCINCTUM, 11. S. 

C. (Elephantulum) t. tenue lirafd, lirls plus minusve acutis, 
confertis seu subdistantibus ; plerumque hue et illuc, maxiine 
aperturain versus, annulis incrementi obsoletis cincta, sub liris 
monstrantibus ; albidd, seu alba et corned concentrice undato- 
nebulosd ; septo submucronato, siobungulato ; ■mucrone dacty- 
liformi ; apice plerumque maxime prominente, laterali, acuto ; 
margine laterali subconcavifer ascendente : operculo valde con- 
cava, anfr. circiter xii. lird prominente spirali, marginem inter- 
dum quasi duplicante. 

This very variable species shews a tendency both in its young 
and old stages, sometimes very much, sometimes scarcely 
developed, to form rings of growth under the ribs, which cross 
them like the varices of Scalaria. The ribs are sometimes fine 
and close, sometimes strong and rather distant, sometimes 
degenerating into mere angles. A few very fresh specimens 
were found, with white and horny brown beautifully mottled 
in concentric portions. The whirls of the operculum are fur- 
nished outside with a very strong rib, which makes the margin 
sometimes appear double. The plug is generally extremely 
prominent at the side, flattened anteriorly, and rising into a 
fiuger-like pointed knob behind. Sometimes however the 
whole surface rises, and the apex becomes rather more tentral. 
llarely in very young shells (when it is extremely sharp) it is 
rather sinistral ; but as the vil)s then take a somewhat spiral 
line down the tube, it is presumed to be merely accidental. 
Only imperfect specimens of this form have yet been seen from 



818 MAZATLAN TNIVALVES 

other seas ; these, from the sponge of commerce, and from the 
Isle of France (Beau) appear distinct ; those from "Singapore" 
(among Chamse and Plicatnla?, P. P. C.) offer no grounds of 
specific separation. I have not however ventured to insert 
them in the habitat, as a larger series of perfect shells may 
shew distinctive characters. From Mazatlan traces were found 
(including varieties) of 51 specimens, of which about 20 were 
perfect, and 4 possessed their opercula. 

The smallest measures long. '04i7, lat. '017. 

The longest „ „ -145, „ '015— -025. 

The largest „ „ -14, „ -02 —-032. 

.ffai. — Mazatlan ; very rare, off Chamse, Spondyli, &c. ; 

L'pool Col. 

Tablet 1518 contains 7 specimens varying in age and sculp- 
ture, with a fragment having C. firmatum interwedged.— 1519, 
1 fresh sp. with operculum ; ribs close and deeply chiseled. 

Var. TENUILIEATTTM ; t. liris crebris, tenuibtis ; apice parum 
prominenti. Tablet 1520 contains 1 specimen. 

Var. sUBOBSOLETtJil ; t. alba, alabastro simili ; liris paucis 
inierdum vix monstrantibiis. Tablet 1521 contains a young 
and an adult specimen. 

Var. STTBCONICTJM ; t. septo maxime elevato, subconico. Tablet 

1522 contains a perfect, and a worn specimen. The latter 

appears to have its apex subcentral, and may be distinct. The 

value of the several distinctions above named cannot be tested 

■ till more specimens are procured. 

Among all the specimens of Mazatlan Csca, only one was 
found with its spiral apex. It was so extremely frail that (not 
however until after careful observation) it dropped off on touch- 
ing with a camel hair pencil. This portion possessed two whirls, 
of somewhat irregular flattened growth, differing in texture 
from Vitrinella, and much smaller, measuring only '006 by '004. 
About half a whirl however remained on the shell, separated 
from the normal part by a very distinct suture. On removing 
this, it was found that no plug had yet been formed. The 
species is therefore indeterminate, as the shell is in the main 
smooth, with extremely taint traces both of concentric and long- 
itudinal sculpture. It is placed provisionally under C^ lirato- 
cinctiun. The normal part measures long. "028, lat. "OOIS— '009. 

Tablet 1523 contains the specimen. 



MAZATLAN UNIVALVES 319 

365. C^CITM HEPTAGONUSr, n. S. 

C. (Elephantulum) t. septangulatd, angidis valde 2)>'ominenti- 
7ms ; annulis rohmdatis confertis cincta, angulos longitudinales 
supracurrentihus ; aperturd planata, extus hcptagonis forma, 
Intiis circulari, sulco concentrico ornatd ; operculo ? . . . . 

AlthougL. only a fragnieut was found, containing a perfect 
mouth, the shell is so different from all other known species 
of the genus, that it was thought best to name it and thus 
direct attention to its existence. By its strong longitudinal 
angles, it would rank with Elephantulum ; by its concentric 
rings, (traversing these angles) with Anellum. The front view 
of the aperture exactly resembles an old-fashioned clock-face 
in miniature. In a flat surface with a heptagonal border is 
cut a circular hole surrounded by a ring. The discovery of 
tliis curious link, which was on the point of being discarded, 
shews the importance of not rejecting fragments. The diame- 
ter of the mouth is ext. "02, int. '01b. 
Hah. — Mazatlan ; 1 imperfect sp. off Spondylus ; TJpool Col. 

Tablet 1524 contains the fragment. 

Section B. Anellum. 

C. t. rare elongata,juxta aperturam parum constrictd, annulis 
concentricis testa aduUd cincta. 

366. Cectjm elongatum, n. s. 

C. (Anellum) t. elongata, tereti ; primuni laivi, dein annulis 
rotundatis, j^ariim extantlhus instructd, interstitiis minimis ; 
.-iepto ungulato, apice parum elevato, subobtuso, margine laterali 
subrecto ; operculo ? . . . . 

? Var. semiLjEve ; t. hue et illuc annulatd, hue et illuc Icevi. 

Known from C. firmatum by the elongated form, and by the 
scarcely raised rounded rings with verj- small intei'stices ; also 
by the plug, which is ungulate, with the apex not dextral and 
rather broad. Of the ? variety, three specimens were fotmd, 
not ijerfect enough for description, but most probably distinct. 
They seem to have relations with C. liratocinctum, but shew 
no trace of longitudinal ribs. One fragment presents a few well 
marked rings between smooth spaces. Another very large 
but rubbed specimen has a sudden contraction followed by a 



320 MAZATLAN UNIVALVES 

very large swelling previous to the aperture. It measures 
Jong. '112, led. (juxta apcrtui'am) "025 — *028. 

Of the typical form about a dozen sp. were found, but most 
of them were rubbed. They present however the different stages 
of growth. The youngest measures fo«^. '06, Za^. '008— '017. 

The largest „ „ -103 „ 'OlS— '023. 

A fragment (Pconspecific) ,, „ •(327. 

Sah. — Mazatlau ; extremely rare, off Spondylus ; L'pool Col. 

Tablet 1525 contains 4 sp. and fragment of different ages, 
typical form. 

Tablet 1526 contains 2 sp. ?var. seniilaeve. 



367. C^CUII SXJBIMPEESSUM, n. s. 

C. (Anellum) t. elongatd, haud jjarvd, solidiore ; annidis 
creberHmis, rotundatis, haud extantibus, interstitiis parvis, 
seepius suhimpressis ; septo mucronato ; margine laterali vix 
concavo ; mucrone parva, obiusd, ad dorsum sitd ; operculo 
? concavo. 

Of this species only 2 adult and 6 young specimens were 
found ; these, being in different stages, have to be retained. 
The sculpture and habit of growth resemble those of C. elonga- 
tum ; from which it differs especially in the naiTOw mucro. 
The only specimen possessing the operculum is of aberrant 
growth. The sutures are least impressed in the very earliest 
stages. The smallest sp. measures long. "058, lat. '008 — '016 

The largest „ „ '115, „ '017— 'OS. 

Hab. — Mazatlan ; extremely rare, off Spond3dus ; Upool Col. 

Tablet 1527 contains 7 specimens in different stages of growth, 
of which one possesses the operculum, and another is curiously 
deformed. 



368. C^CUM riRMATUM, C. B. Ad. (diagn. aucf.J 

C. f Anellum) t. robustd, arcuatd, satis tereti ; aperturd vix 
ron.strtctd ; t. juniore primum Icevi ; dein annuiis circiter 
xxiii. — xxxiii., primum acutioribus, dein parum qtiadrati-i ; 
interstitiis suhquadratis, plus minusve distaniibus, interdum 
aperturam rertius eranidis ; septo siibungiilato ; apice partem 
prominente, xuhdcxtrorsum sito, obttisiore, latiore ; margine ad 
latus subrecio ; operculo ? . . . . 



' MAZATLAN TTNIVALTES 321 

Ccecum firmatum, C. B. Ad. Pan. Shells, no. 213, pp. 161, 311. 

+ Ccecum eburneum, C. B. Ad. do. no. 212, pp. 161, 311. 

+ (adolesc.) CcBCum monstrosum, C. B. Ad. do. no. 216, pp. 162, 

311. 
+ (adolesc.) Ccecum pygmseum, C. B. Ad.A.o. no. 218, pp. 163, 311. 
? + (jun.) Ccecum diminutum, C. B. Ad. do. no. 211, pp. 161, 310. 

The fortunate preservation of specimens in the Cumingian 
collection, received from Prof. Adams himself, (viz. 3 of C. 
firmatum out of 85, 3 of C. eburneum out of 22, 2 of C. mons- 
trosum out of 7, and 1 of two of C. p.vgma?um) which, through 
the wonted kindness of H. Cuming, Esq., I have been enabled 
to subject to a rigid microscopical examination and comparison 
with the Mazatlan specimens, enables me to give the above 
synonymy with tolerable confidence, in spite of the worn state 
of most "of the shells. Of C. diminutum. Prof. Adams only 
found one specimen. As far as can be judged from the des- 
cription, it is the early stage, long and slender. The next 
stage, appears to be C. pygmajum. C. monstrosum partakes 
half of this, and half of the adult form. A similar state is 
found in other species, when there is any quantity of specimens. 
C. eburneum and C. firmatum are to one another as the English 
forms C. imperforatum and trachea. The rings in the Cum- 
ingian specimens of C. eburneum vary from 26 — 33. and are 
more or less pressed together near the aperture. This char- 
acter is extremely variable. The largest specimen here given 
is exactly intermediate between the two forms. It appears 
very rare at Mazatlan, where it is represented by C. undatum. 

C. firmatum is distinguished from nearly allied species by 
the following characters. Eibs somewhat flattened and squared, 
with deep rather squared interstices. Plug intermediate be- 
tween the ungulate and mucronate forms ; rising gradually in 
a nearly straight line to the summit, which is placed rather to 
the right, somewhat broad but thin, with the apex rounded. 
The youngest shell (probably belonging to this species, but the 
plug is rather imperfect) is quite smooth in the first part, 
but afterwards ringed ; it measures long. '067, lat. 'COS — '012. 
The next shell, measuring long. '018, lat. '008— "013, is grace- 
fully bent and tapering, and entirely ringed. The next, in the 
'pygmajum' state, measures long. "063, ltd. "013— '017. The 
rings on first appearing are rather sharp and distant : tliey 
gradually assume the normal type ; sometimes however run- 
ning into each other, in the 'eburneum' state. The largest 
specimen measures Zo /;.(/. "1, led. '016 — '025. 



322 MAZATIAN UNIVALVES 

Sab. — Panama ; common in the sand ; C. IB. Adams. — 
Mazatlan ; 14 sp. off Spondylus &c. ; L'pool Col. 
Tablet 1526 contains 5 specimens in different states. 

369. C^CUM CLATHEATtlM, n. S. 

C. (Anellum) t. haud parva, solidiore, annulis valde distanti- 
bus, acutioribus, validis, extantibus, citictd; interstitiis concavis; 
septo subplanato, mucronato ; in adultd margine laterali haud 
monstrante ; mucrone yninimd, obtusd, pcene in dorsum slid; 
operculo /*.... 

This extremely elegant species is remarkable for its size ; 
very distant bar-like rings, which are rather sharp ; gracefully 
curved interspaces ; and nearly flat plug with a scarcely pro- 
minent obtuse mucro, scarcely (if at all) inclined to the right. 
Only 12 specimens were found. The youngest sp. measures 
long. -057, lat. -(X)?— '017. The largest, long. -102, lat. (inter- 
stices) '026, (outside) '03. 
Hab. — Mazatlan ; off Spondylus, extremely rare ; L'pool Col. 

Tablet 1528 contains 4 specimens of different ages. 

370. C^CIJM QUADEATril, 71. S. 

C. (Anellum) t.parvd, curtd, solidd, annulis quadratis xii. — 
XX. cinctd ; interstitiis profundis, quadratis ; aperturd sub- 
contractu, annulis connnTentibus -, septo mucronato, margine 
laterali concavo, mucrone parvd, extante, angustd, subdextrorsum. 
sitd : operculo valde concavo, anfr. circiter x. lined spirali 
expressd. 

iVar. COMPACTUM, t. interstitiis parvis seu evanidis, annulis 
maxime planatis. 

The extreme forms of this shell are singularly different ; at 
one end of the scale being a larger shell, muricated with 
squarislj distant rings, passing into C. clathratum ; at the 
other, a small stunted state in which the rings have so run 
together that the interstices appear like simple grooves, and 
the shell approaches the young of C. subimpressum. Among 
43 specimens found, however, (of which 3 possessed opercula,) 
there appeared too gradual a transition to allow of their separ- 
ation. At the same time the habit of growth appears q\iite 
distinct from that of any of the neighbouring species. It is 
customary for Auella to make their rings compact in the mature 



MAZATIAN UNITAIVES 323 

state ; but some specimens sbew that in tliis species tbey are 
often compact in tlie very young state, and become looser 
afterwards. Tbe variety 'compactum', though smaller than 
the typical condition, may be a dwarfed form. The species is 
known by the great prominence and squareness of the ribs and 
interstices ; the compact growth ; and the plug, which is 
nearly flat over the sui-face, gradually rising in a curve to the 
little finger-shaped mucro, which is blunt at the top, short, and 
placed somewhat to the right. An extraordinarily large sp. 
measures long. "072, lat. (interstices) "016, (outside) '02. 
Sah. — Mazatlan ; rare, in Spondylus and Chama ; L'x>ool Col. 
Tablet 1529 contains 7 specimens, typical form, in different 
conditions of growth, one of which has the opercidum in situ. — 
1530, 7 do. var. compactum, and intermediate forms. The 
youngest specimen is somewhat doubtfully afiiliated. 



371. C^CTJM rrNDATTTM, In. s. 

C. (Anellum) t. juniore exili, gradle tereti, plus minusve arcni' 
atd, Icevi, nitidd, aperttird Jiaud declivi ; testa adiiltd ciirtd, 
obesd ; extremitatibus ad amjulutn circ. 115° altera ad alteram 
truncatis, utriyique contractu, vix annulatis ; aliter, super- 
ficie eleganter undatd, annulis (numero variantibus x. — xv.^ 
acutis, 2jIus minusve extantihus, interdum vix monstrantihus ; 
interstitiis concavis, Icevibtis •faperturdprimum contractd, deinde 
paululuni reflexd, acuta ; se2)to tijpice iingulato ; lateraliter mar- 
ginihus rectis, triangulum scalenumformantilnis, apice laterali, 
aeuto, prominente ; ad frontem regulariter excwrvato, tumente. 
Operculo extus concavo, mtiUispirali, anfr. circiter xv, suturd 
distinctd, margine simplid. 
Adolesc. .? = C. parvum, C. B. Ad. Pan. Shells, pp. 163, 311 : 

"t. arcuatd, gracili, vix tereti ; albidd ; annulis xv. acutis, 

distanfibiis, hand midtum elevatis : apice laterali, prominente. 

Long. "065, lat. "019." Sp. un. 

The description of C. B. Adams' unique specimen being 
imperfect, I did not feel at liberty to aflfiliate the very numerous 
series of Mazatlan shells, merely because the ribs were sharp, 
to a species whose name is applicable to the whole genus. The 
specimen is howeyer most likely the adolescent state of this 
species, after the waved rings have been formed, but before 
tlie final contractions. The yoimg state of this shell cannot be 
distinguished from that of the next species. It is long, slender 



324 MAZATLAN TTNIVALVE9 

and smooth, with the mouth at ripht angles. The successive 
portions ai-e not formed b}- uniform progression ; but often a 
very sudden turn is seen in the arcuation, or rapid thickening 
of the body. The most singular state is when the thick aunu- 
lar part is just beginning. Then at the end of a smooth slender 
tube we have a bowl with three or four rings outside suddenly 
rising at a marked angle, not unlike a short tobacco pipe. The 
rings are often nearly evanescent, when the shell can hardly 
be distinguished from the next species. It is found of very vari- 
able lengths in its growing state; perhaps from the decadent 
portion not always falling off immediately after the new part 
is formed.* The greater or less prominence of the plug appears 
due to the same cause. The sharply triangular outline of its 
profile is characteristic of this and the next species. The shell 
in its adolescent state would appear to stand at a considerable 
angle to the plane of the animal's foot : but when adult, it is well 
fitted to make its way along the narrow worm-eaten galleries 
in which it is generally found. The mouth is then so slanting 
that the two truncations of the cylinder form an angle of about 
115° to each other. This is conti*acted at each extremity ; the 
contracted part not being waved. The mouth, after being 
very much narrowed, makes a slight sharp expansion all round, 
like the neck of a jar. The texture of the shell is sometimes 
like alabaster, sometimes slightly waxen, perhaps from the 
epidermis. This appears to be the common species at Mazat- 
lan, as C. firmatum is at PanamC about 320 specimens alto- 
gether having been found : of these 37 fortunately possessed 
the opei'culum. This tiny body, which in an adidt shell is only 
"013 across, nearly filling the constricted aperture, is very con- 
cave externally, with a central nucleus and about 15 whirls, 
which arc for the most i)art strongly marked, with an entire 
margin. The youngest among the specimens which were 
found perfect measures long. '042, lat. "01. 

A sp. (form monstrosum) „ „ •067, „ '01 — '02. 

An adult „ „ '074, „ -021. 

• The very complex nature of the plug in all the Caeca, apparently formed by 
successire layers like ordinary shell, and not of uniform material like the septa 
in Turritella, Vermotus, &c., taken in conjunction with the variable length of 
specimens apparently of the same age, leads to the conjecture that the same plug 
may be carried onwards during the life of the animal ; that after making a fresh 
length, it loosens the plug, (a Iding to its margin,) and fixes it in its new locality. 
Perhaps at the same timn it disengages the old portion ; as the edges are always 
regular, differing from Melaniae, TruncatellK, &c. which rot ofl' of themselves, 
and the shell is never found with the disused portion adhering. A second Clark, 
keeping a Vivarium of Cicca in an old Spondylus, might reveal charming anec- 
dotei of the habits of these creatures 1 



MAZATLAN UNIVALVES 325 

J5«5.— Mazatlan ; abundant on Spondylus, not uncommon on 

Chama, Modiola capax, &e., rare on Ostrea iridescens ; 

L'pool Sf Havre Coll. — PPanama, 1 sp., C. B. Adams. 

Tablet 1531 contains 4 sp. smooth state.— 1532, 11 do. partly 
smooth, partly waved.— 1533, 4 do. waved state adolescent. — 
1534, 7 do. adult.— 1535, 2 sp. jun. and 2 adult, with opercula. 

Tablet 1536 contains 4 sp. deformed growth, and 1 uierced by 
a tiny proboscidean. — 1537, 1 ?p. plug extremely prominent ; 1 
do. with the profile line very slightly arcuated ; 1 do. deformed. 

Tablet 1538 contams 3 sp. probably belonging to this species, 
but closely approaching C. Ia3ve. ' . 



Section C. Faetulum. 

C. t. IcBvi, cylindracea, scepius utrinque coniracta ; aperturd 
scspe declivi. 

This group is named from the general resemblance in form 
to a little sausage. Some species however approach the long 
tapering Elephantulum, while others are approached by the 
ringed Anellum. 

372. C^ICUM LiEVE, C. B. Ad. (diagn. auct.) 

C. (Fartulum) t. junior e " C. undaio" exacte simulante ; 
t. adultd eidem simili, sed la;vi, nitidd, Jiaud undata,, irJerdi'.m 
ante apertiiram plus minusve tumidiore ; apiertwrd et apice 
minus contract d ; operculo concavo, suturis minus distinctis, 
texturd semicorned, hrunneo tincfd. 
C. B. Ad. Pan. Shells, pp. 162, 311, no. 214. 

This shell, imperfectly described by Prof. Adams from two 
specimens varying in age, is so remarkably liice C undatum 
uot only in its general habit but in several minute pai'ticulars, 
and especially in the shape of the plug and mouth, that aber- 
rant individuals of each are very dithcult to distinguish. I 
know of no character by which the youug shells can be separ- 
ated. Wlxen it arrives at the "monstrosum" stage, the 
absence of imdulated rings in the bowl of the pipe becomes a 
marked and uniform character. lu the adult, the cylinder is 
rather less contracted at the two ends, and tlio aperture a 
trifle less slanting. Before the contraction of the aperture, 
the tube is sometimes swollen, which has never been observed 
Sept. 1856. ee 



326 MAZATLAN UNIVALVES 

in C. undatum. About 170 specimens were found (of which at 
least 4i possessed their opereula) agreeing in the above dis- 
tinctive characters. The texture of the shells, when fresh, is 
not alike in the two forms ; C. undatum being of a somewhat 
waxen white, or alabaster : C. la;ve being of a more horny 
tolour, occasionally developing a marked bro\vn, especially 
withm, where it frequently leads to delusive hopes of finding 
the operculum. This is of the same size and concavity as in 
C. undatum ; but in the specimen examined within does not 
possess the sutural line, and the whirls are apparently fewer. 
The smallest specimen measures long. '035, lat. '(XJo — '01. 

An unusually large one ,, '07 „ '018. 

Hah. — Panama ; extremely rare ; C. B. Adams. — Mazatlan ; 

not uncommon, on Spondylus, Chama, &c. ; L'pool Col. 

Tablet 1539 contains 6 »p. very young, of different curvatures 
and proportions. — 1510, 6 sp. 'monstrosum' period, do. — 1541, 
1 sp. adolescent. Of these two have the profile line of the plug 
somewhat swollen, and one is more tapering than usual. The 
latter may be the yoimg of some other species.-^1512, 6 sp. 
adult, varying in colour, arcuation, &c. One of them is curi- 
ously and beautifully encrusted ; and another retains part of 
the decollated portion round the plug. — 1543, 6 sp. of different 
ages with their opereula. One is of deformed growth -. another, 
of mature breadth, is so short that it would have been consider- 
ed broken were it not for the operculum. This seems to shew 
that the animal is not necessarily as long as the persistent shell. 
(Comp. C. abnoraiale, p. 31(5.) 



373. Cecum fakcimen, n. .s. 

C. ( Fartuliim) t. " C. Icavi" simili, ■■ied alhidd, aperturd yuinus 
contra ctd ; t. adultd et Interdiim adulesccnte, annulis rotundatis 
paucis subohsohtis aperliLram plerumqicc prcecedentihus ; .septa 
plcrumque hand elevato, apice laterali suhprominente hand acufo, 
utrdque parte angiistd; ad frontem mueronatd, ad latus mar- 
gine parum ascendente, Jiaud rectd ; operculo concavo. 

This species differs from C. Lbvo, which it is very much like, 
in shape, size and general appearance, in the form of the plug 
which ("losely resembles that of C. firmatum. It rises very 
nlowly, and in a somewhat swollen line, to a distinct lateral 
knob which is short and narrow. The shell generally (but not 
always) develops obscure rings near the aperture. In the only 



MAZATLAN UNIVALVES 327 

Specimen found in the adolescent state, these ribs remain 
between smooth portions, shewing the position of a former 
mouth. An immature specimen displays, under a high power, 
extremely minute longitudinal irregular wrinkled striee, which 
are probably due to the epidermis. One operculum was found 
in sitxi, which appears somewhat less concave than in C. Iseve, 
but .it was not extracted. An unusually large sp. measures 
long. -064, lat. -019. 
Sab. — Mazatlan ; very rare, off Spondylus, &c. ; L'pool Col. 

Tablet 1544 contains 4 sp. ; viz. 1 adolescent, 1 immature, 
and 2 adult, one slender, the other swollen, with operculum. 

Tablet 1545 contains a sp. probablj^ belonging to this species, 
with the plug abnormally swoUen and the knob divided. 

374. C^CCM GLABBIFOEME, 11. S. 

C. (Fartulum) t. " C. glahro" similUmi, sed septo mamillato 
tumentiore,fere hemlspherico ; operculo ? . . . . 

One young and four adult specimens were found (with 
fragments) ; but all were dead, and the operculum was not to 
be seen. It is almost exactly like the British species, differing 
in being a trifle broader, and in having the regularly hemi- 
spherical plug much more swollen, as in the young of C. gla- 
brum. The mouth is sharp, and scarcely contracted. It would 
have been curious to see whether the quoted convex operculmn 
of C. glabrum finds its analogue in this species. Long.'OlZ, 
lat. -017. 

Sab. — Mazatlan ; extremely rare, off Chama ; L'pool Col. 

Tablet 1546 contains 2 sp., young and adult, the latter, 
though broken, being the most characteristic in the prominence 
of the septum. In the Britisli specimens, as well as in those 
from Mazatlan, the amount of tumidity varies not inconsider- 
ably ; so that the most prominent British shell scarcely differs 
from the least prominent Mexican. If it were not for the 
imcertainty of the operculum, added to the remoteness of 
habitat, the species might be united. 

375. CiCUM COKEUGTJLATUM, n. S. 

C. (Fartulum) t. " C. glabriformi" simili, sed tumidiore ; 
superficie temiissime transversim striatd, striuUs nu7iimis irregu- 
lariter corrugata; septo ?mammillato; operculo ? 



328 MAZATLAN UNIVALVES 

Tliis species is constituted from a single imperfect specimen, 
in consequence of the i^eculiar sculpture wliieli lias not been 
observed in any other Mazatlan species. The shell appears 
smooth ; but under a high magnifying power, it is found to be 
covered with most minute irregularly concentric wrinkles, like 
the lines on the thumb, or the muscular scar in the operculum 
of Murex nigritus. The plug appears to be mammillated ; but, 
with the aperture, is imperfect. The sculpture, shewing so 
decidedly on a dead shell, must be very beautiful on a perfect 
specimen. Long. '075, lat. "017 — '022. 

Sah. — Mazatlan ; 1 sp. off Chama ; L'pool Col. 

Tablet 1547 contains the specimen. 

376. C^cctm; dextkoveestjm, n. s. 

C. (Fartulum) t. teretl, satis elongatd, alhd, tenui, Icevi : septo 
tumido, submammillato, mitcrone tmnidissimo, dextrorsiim later- 
aliter verso; apertura parum declivi, haud contracto ; operculo 
vix concavo. 

In this species, as in C. laqueatum, the mucro, instead of 
being in the middle or at the back of the shell, is turned to the 
right ; where in the young shell, which is extremely thin and 
slender, it appears as a conspicuous knob. As the shell 
increases, the body of the plug swells out and becomes mammil- 
lated, so that in certain portions it can scarcely be told from 
C. glabriforme, especially as the central knob is apt to be 
rubbed off. It is however a larger and more tapering shell. 
The youngest specimen, which only measures "023 by "008, 
possesses its operculum. This was also found in three other 
young shells, but all the adult specimens were dead. It ap- 
pears to be nearly flat, but perhaps may become more concave 
in its adult state. The species presents such different appear- 
ances at different periods of its growth, being sometimes long 
and slender, at other tinics short and stumpy, that it has been 
necessarj'^ to preserve a large part of the few found. An un- 
usually large and stout sp. measures long. "092, lat. '024. 

Hab. — Mazatlan ; very rare, (20 sp.) off Spondylus, &c. ; 
L'pool Col. 

Tablet 1548 contains 9 specimens, in different stages of 
growth, of which 3 possess their opercula, 



MAZATLAN tTNlVALVES 329 

377. Cjecum eevebstjm, n. s. 

C. (Fartulum) t. juniore " C. dextroverso" simiti, sed septa 
suhconvexo, mxicrone rcversd, semi-cylindraced, arcuaid, aper- 

turam vet'sus convexd, dorsum versus concavd ; t. adultd ? ; 

operculo ? 

This species is constituted from a single young sliell, in 
consequence of tlic extreme peculiarity of its plug. Tliis, 
instead of having the apex turned to the back of the shell, (or 
central as in the mammillated species,) has the highest part 
towards the front. It appears like a miiiute curled Carjum, 
lying on the shghtly s?rollen surface of the plug, with its back 
towards the mouth, and its horns towards the back of the shell. 
It was at first regarded as a monstrosity of one of the other 
species ; but a careful examination xmder a high power shews 
it to be quite regularly formed. Long, "Ol'S, lat. '012. 
Sab. — Mazatlan ; 1 j'oung sp. off Spondylus ; L'pool Col. 

Tablet 1549 contains the specimen. 

378. C^CtTM TEEES, ». S. 

C. (Fartulum) t. elonyatd, arcuatd, tcreti, Icevi; longitudin' 
aliter interdum obsolete subangulatd ; albidl, sev, hue et illuc 
semicorned ; apertura parum constrictd, dein minime reflexd, 
parum declivi ; septo miicronato ; mucronem versus ijarum 
ascendente margine subrccto ; mucrone ad froiiteni subelongata, 
adj lotus angustd, pai'^d, ohtusd : operculo vix coneavo. 

This species forms the transition from the smooth to the 
ribbed forms; having the shape of Elei)hantulum, with the 
sculpture of Fartulum. The plug reseiubles that of C. farci- 
men, but the mucro is rather broader in the front view, though 
narrow at the side. The operculum, found in a young speci- 
men, can scarcely be called concave. The texture in the finest 
specimen is in concentric portions of dirty white or horny, 
irregularly mottled. Only 5 sp. were found, in different con- 
ditions. The smallest measures long. 'Oio, lat. ■012. 

The largest „ „ '115, „ -017—027. 

Hah. — Mazatlan ; extremely rare, off Spondylus ; L'pool Col 

Tablet 1550 contains 3 sp. of different ages, the middle one 
possessing its operculum. 

Tablet 1551 contains 3 pseudo-caseous bodies, inserted for 
comparison. The largest of these, measuring '045 across, was 



330 JIAZATLAN r>:iTALVES 

regarded by irn^nr campctent coneliologists as part of a gigantic 
Cs-' \m, aaf? is ilio "PCfficum, no. 9" of my ms. catalogue. I 
doubt wlicliier auy of these objects be of Molluscous origin. 



Family TUEPJTELLrD.E. 

Gextjs TUEEITELLA, Lam. 
S. &C A. Ad. Gen. vol. i. p. ?,ol.—Fhil. Sandh. Conch, p. 164. 

379. Tuehitella goniostoma, Val. 

Turritella gonostoma, Val. Hec. Ohs. Sumh. vol. ii. p. 275. 
T. goniostoma, Kien. Icon. Conch, p. 21, no. 16, pi. 10, f. 1, 

(bene).— &ia, Mus. vol. iii. pi. 56, f. 2Q.—Rve. Conch. Ic. 

pi. 3, sp. 10, f. 10, a, b.—Mke. in Zeit.f. Mai. 1850, p. 165, 

no. 11. 
Haustator (TurriteUa) goniostoma, H. Sf A. Ad. Gen. i. 352. 
+ Turritella lentiginosa, Rve. loc. cit. pi. 3, sp. 9, (Payta, 

coarse sand, about 5 fm. Cuminr/) — JI. ^' A. Ad. Gen. i. 351- 
? + T. Hookcri, 3Ike. loc. cit. no. 12 :— non Bve. loc. cit. pi. 11, 

sp. 61. (Antarctic Seas, Capf. Soss.) 
Comp. T. Banksii, Rre. loc. cit. pi. 4, sp. 15.— C. B. Ad. Pan, 

Shells, p. IGO, no. 210.— = Haustator B. H. Sf A. Ad. Gen. i. 

352. 
= T. Broderipiana, D'Orh. B. M. Cat. Moll. p. 31, no. 279. 

" = T. Califoruica, Brod. [!] Pyouug." 

This species was first described from a small shell, an inch 
long, with 12 turns of spire, brought from Acapulco by Hum- 
boldt & Bonpland. Its W. Indian analogue is Turritella 
meta, Rve. (v. Phil, in Kust. in loco.) The form distin- 
guished as T. lentiginosa, having the colouring "in short, 
transverse, linear dashings" is not so aberrant as many here 
catalogued. The T. Banksii has rather a more delicate style 
of sculpture, but is not improbably only a variety of the same 
species. Of the changes of colour and pattern, a sketch is 
given in the list below. In shape, it is either nearly smooth 
(except spiral stria;) with flattened whirls ; or with the whirls 
moderately swelling ; or, more usually, with an obtuse keel on 
the shoulder, and a few others below. The base is always 
ribbed, and the periphery more or less sharply keeled. It is 
common to find shells beguining with one form and pattern. 



MAZATLAN UNIVALVES 331 

and cliangmg to another. Tlie adolescent portion is generally 
swollen, of smootlicr growth ; the adult with the whirls irregu- 
lar, more or less drawn out, and frequently with sharp ridges 
of growth behind the labrum. But whatever condition the 
adult maj' assume, the young shell always has one sharp spiral 
keel in the niiddle of each whirl, surrounded by spiral stria. 
The operculum is of uniform coloiu% with about 18 whirls ; 
with one row of sharp tubercular hairs next the suture, and 
other more stumpy ones following ; with a very fine border, 
radiately striated, followed by a long hairy fringe. The 
youngest sp. has five whirls, of which the first two are smooth. 
It measures '018 by '028. An adolescent specimen (12 whirls) 
measures long. 2'07, lo7ig.spir.l'64s, lat. '7i, div. 22°. 

The largest (17 whirls) 4-5, „ S'SS, „ '98, „ lO". 

Aslendersp. (15 whirls) 3-7, „ 3-2, „ "82, „ 8". 

Sab. — Acapulco, Sumholdt Sf Bonpland. — Panama, Kiener. — 

Payta, Salango, Guaeomayo ; in sandy mud, 5 — 10 fm. ; 

Cuming.—^. W. Mexico, P. P. C— jMazatlan ; not uncom- 
mon ; L'pool Col. 

Tablet 1552 contains 6 sp. exti'emely young. — 1553, 2 sp. 
young ; one passing from chalcedony to purple brown, then 
suddenly to nearly white, then gradually to dark, linear 
pattern. 

(1.) Tablet 1354 contains 2 sp. uniform purple black ; one, 
whirls flat, the other rounded. — 1555, 2, sp. very dark, tinted 
with orange brown.— 1556, 2 sp. black purple ground, slightly 
variegated with white. — 1557, 3 do. normal state, with more 
white ; one has passed through acid, to display colour. — 1558, 
3 do. pur])le, light abounding ; one in dashes above, clouded 
below ; another with both large and small pattern. — 1559, 3 do. 
light predominating ; brownish purple in clouds, dashes or 
spots. 

(2.) Tablet 1560 contains 3 sp. dark olive brown, with purple, 
linear i^attern or variegated. — 1561, 2 do. white abounding.— 
1562, 3 do. light tint, linear markings conspicuous. 

(3.) Tablet 1563 contains 1 sp. purple brown passing into 
orange brown. — 1564, 2 sp. nearly uniform orange brown ; one 
nearly smooth, with blunt shoulder keel; the other rough, 
keeled above and below. — 1565, 3 do. with faint ptii^ple brown 
cloudings ; one very slender, lower whiiis separating. — 1566, 
2 do. lower whirls passing into normal colouring. — 1567, 2 do. 
upper half of the whirls richly' variegated. — 1568, 3 do. light 
predominating ; pattern clouded or dotted. 



333 MAZATLAN TTNIVAIVES 

Tlie above series, arranged from tlieir predominating colouis, 
mutually pass into each other. They present the extremes of 
form and sculpture, and several possess their opercula. Tablet 
1569 contains 3 sp. richly coloured and sculptured, with pro- 
jecting ridges of growth conspicuous near the mouth.— 1570, 
2 sp. after severe fractures, spire twisted. 

Tablet 1571 contains a miuute specimen, "038 by •02, which 
may belong to this species, but develops the spiral keel much 
earlier and more strongly than usual. 

380. TcTBEITELLA TIGEINA, Kien. 

Icon. Conch, p. 29, no. 22, pi. 4, f. 2.—Bve. Conch. Ic. pi. 3, 

sp. 8.— J/Xt. in Zeit.f. Mai. 1850, p. 164, no. 10. 
Haustator (Turritella) tigrina, JS. Sf A. Ad. Gen. i. 352. 
= T. imbricata, MIlC. (quasi Lam.) Zeit.f. Mai. 1847, p. 178, 

no. 3. 
Comp. T. Cumingii, JRve. loc. cit. pi. 4, sp. 13. (Panama, 

11 — 16 fm. Cuming; Conchagua, _Be/^c/ie/'; Gulf of California, 

sandy mud at low water. Rev. — Steel.) 
Comp. T. iiubricata, {Lam. var.) Kien. loc. cit. p. 11, no. 8. 

pi. 9, f. 2a. 

(Light var.) Comp. T. leucostoma, Val. Bee. Ohs. vol. ii. 
p. 275 -.—Kien. loc. cit. pi. 6, f. 2 -.—Bve. loc. cit. pi. 2, f. 5. 
(Acapulco, Kumholdt Sf Bon^land ; Gulf jSficoyo, sandy 
mud, 11 fm., Cuming.) 

Very few specimens, and those for the most part dead, were 
found of this species. It is not swollen in the middle of the 
spire ; the periphery has a blunt angle ; and the upper whirlg 
have at least five spiral lirid;c. The usual painting is a pre- 
vailing white, with large purple-black patches : but sometimes 
the coloured part is light reddish brown, very HI defined. 
Opercidum with about 17 whirls, the outer ones fringed with 
a lighter colour, transversely va-iukled, and with a few spiral 
rows of hairy tubercles. A specimen ^ith 22 whirls measures 
long. 3'33, long. spir. 2'87, lat. "76, div. 15°. 

Sab. — Gulf of California, Reeve. — IMazatlan ; extremely rare ; 
L'pool Col. 

Tablet 1572 contains a young sp. of 5 whirls, measuring "049 
by '018. The first two are smooth ; the rest much rounded, 
with fine spiral striae. 

Tablet 1573 contains 2 normal sp., one with operculum, the 
other after acid. — 1574, 1 sp. light var. 



mazatlan univalves 333 

Family CEEITHIADJE. 
Genus CEEITHRTM, Adans. 

Ceritliium, Adanson, pars.— ^. 8f A. Ad. Gen. vol. i. p. 284.— 
Shell with short, scarcely recurved canal ; columella not 
plicated ; paries callous ; operculum Littorinoid, thick. 

381. Cebithium 3IACUL0SUM, Kien. 

Kien. Icon. Conch, p. 36, no. 25, pi. 13, f. 3, (non 2.)— Lam. 

An. s. Vert. vol. ix. p. 312, no. 4:0.—Mke. in Zeit. f. Mai. 

1850, p. 178, no. 39.— (j^on Vertagus maevHosus, Marfi/n.J 
Cerithium adusturo, fXien. teste 'fig. non diagn.) C B. Ad. 

Pan. Shells, p. 150, no. 193.— P. P. C. Cat. Prov. 
Cerithium nebulosum, Sozo. Thcs. Conch, sp. 71, pi. 179, f. 60. 
? + (var.) Cerithium adustum, Soio. loc. cit. sp. 70, pi. 178, f. 48.— 

(Non Kien. diagn. et f. 2.) 

Kiener accurately- described the Mazatlan shell as C. macu- 
losum, but unfortunately in his plate named it C. adustum ; his 
diagnosis of that species (loc. cit. p. 37, no. 26, f. 2 non 3 ; — 
Lam. An. s. Vert. ix. p. 313, no. 46) being apparently intended 
for a Eed Sea shell. Sowerby (following Desh. and 311-e.) cor- 
rects the error of the plate, but alters both the species. He 
changes the name of this to C. nebulosum, because as he 
describes the whole family as one genus, he finds this temi 
preoccupied: and he affiliates C. adustum to a Galapagos 
shell, which is probably only a smooth variety of the present 
species. The figiire is indeed coloured orange brown; but 
that tint is not mentioned in the description, which accords 
sufficiently well with the Mazatlan shell. An analogous species 
is C. Guinaiciun (Phil.) Sow. from Ld. Hood's Island. 

The Mazatlan species has the first 8 whirls flat, with a 
divergence of 43", and sculptured with about 15 veiy faint 
transverse ribs, crossed by about 5 rather strong lirulse. Here 
and there a varix is formed. Afterwards the costsr change 
into a row of stout tubercles, rather above the middle of the 
whirls, sometimes with a few rows of smaller ones on the body 
and base of the shell. The spiral lirula; become very faint, 
and are marked by lines of brown broken up into dots. Some- 
times there are large iiatches of blackish brown ; sometimes 
the prevailing hue is light. The shell is generally very broad 
and gibbous ; but sometimes it is elongated. The dwarf 



334 MAZATLAlf BIVALVES 

specimens of this form approach Cerithium famelicum, from 
which it may always be distinguished by the row of very 
characteristic crenations alonp; the suture. Sometimes the 
tubercles become rather obsolete, when it has the appearance 
of C. adustum, Soto, (non Kien). The adolescent shells have 
the mouth effuse and the canal straight. Of these very few 
specimens were sent. Afterwards the anterior canal is turned 
sharply back ; the labrum being more or less pinched up at 
the base, so as somewhat to cover it. The large posterior 
canal is formed by the gradual advance of the labrum up 
the spire, pinched up opposite the stout labial callosity. The 
labrum is thin, and with the rest of the peritreme often stained 
with violet. The operculum is not large for the shell, with the 
nucleus sunken, and the few turns of spire scarcely seen out- 
side, but conspicuous in the muscular scar inside. The outer 
margin is smooth ; tho outer surface appears so, but under the 
microscope displays most minute strife in the direction of 
growth, still more minutely decussated into granules. The 
muscular scar is not corrugated as in Murex, but ha& very 
irregularly waved lines breakiug up into circidar spaces. The 
smallest adult measures long. I'OoJong. spir. '63, lat. "4, div. 32P. 
A stumpy sp. „ „ 1'35, „ '65, „ "66 „ 45°. 

An elongated sp. „ „ 1-7, „ -68, „ -68,,, SO". 

Sab. — Acapulco & Galapagos, Kiener. — Galapagos, Cuming. — 

Taboga ; common in wet sand, under stones, at half tide 

level, a B. Adams.— S. AV. Mexico, P. P. C— Mazatlan ; 

very common : L'pool Sf Havre Coll. 

Tablet 1575 contains 3 sp. immature. — 1576, 3 do. adult, dif- 
ferent sizes. — 1577, 3 do. dwarf var. elongated. — 1578, 3 do. do. 
swollen. — 1579, 3 sp. light colour. — 1580, 3 do. usual state. — 
1581, 3 do. dark tint.— 1582, 3 sp. very nodulous, (one with 
operc.) — 1583, 3 do. slightly nodulous, elongate. — 1584, 3 do. 
with repau-ed fractures.— 1585, 2 sp. one with the anterior, the 
other the posterior canal marked off by the abnormaUj"- indent- 
ed labrum.— 158G, 9 opercula. 



382. Ceeithium Pfamelicum, C. B. Ad. 

C. B. Ad. Pan. Shells, pp. 152, 309, no. 196, (pars.) 

= C. uucinatum (Gmel.) Sow. pars. T/ies. Conch, pi. 180, f. 79. 

Var. mediol;«;ve. C. ffamelicum, t. nitidd, epidermide suh- 
politd, striidis spiralibus haud impressi^ : serie tuherculorum 



MAZATLAN UNIVALVES 335 

haud magnorum suh suturam hand impt'essam : serie granulo- 

rum parvorum ad peripheriam, in spird super suturam vix 

monstrante ; altera minorum in hasi ; spird in medio anfrac- 

tuum suhlcBvi ; lahro obscure higonato ; caiiali anteriore longo, 

recto, declivi, vix recurvatu. 

= C. umbouatum, Soto. in. JMus. Cum. 

Comp. Cerithium musica, Val. Rec. Obs. p. 277, (Acapulco.) 

This shell, named C. famelicum by Mr. Cuming as from 
C. B. Adams, does not agree with, the description given by the 
Professor ; still less with that of C. uncinatum, to which Sow. 
unites the species. It more nearly resembles the "W. Indian 
C. litteratum Brug. (Lam. An. s. Vert. ix. 303) but is much 
more slender. It is characterized by the entire absence of the 
stout tubercles ui the middle of the whirls, by a smaller row at 
the top, a still smaller at the bottom, and a yet smaller round 
the base. The labrum has two obscure angles between the 
canals. The glossy aspect of the shell is very characteristic 
and beautiful. The young shell is like the adult, but with 
obsolete ribs instead of tubercles. ILong. '98, Long. spir. *67, 
lat. -38, div. 25". 
JSaS.— PTaboga, rare, C. JB. Adams. — Mazatlan ; 1 fresh sp. ; 

L'pool Col.—S. W. Mexico, do. P. P. C. 

Tablet 1587 contains the specimen. 

383. Ceeithium ? uncinatum, Gmel. 

Murex uncinatus, Gmel. p. 3542, no. 57. — Dillw. Descr. Cat. 

vol. ii. p. 751, no. im.— Wood, Lid. Test. pi. 27, f. 150. 
Murex, no. 19S, Schroet. Einl. vol. i. p. 611. 
Strombus muricatus et marmoratus, Schroet. Flusch. p. 379, 

pi. 8, f. 15. 
Cerithium uncinatum Desh. in Lam. An. s. Vert. vol. ix, p. 315, 

no. m.— Soio. Thes. Conch, pi. 180, f 79. 
? = Cerithium famelicum, C. B. Ad. (pars) icc. cit. 

This species suits with tolerable precision the very accurate 
description of Desh., and in the main that of C. B. Ad. The 
locality however of C. uncinatum is unknown, and it may be a 
distinct though similar Caribba3an species. In that case the 
name C. famelicum may be retained for this shell and C. me- 
diolaeve for the Mexican. This is characterized by the row of 
very stout tubercles ascending the spire in the middle of each 
whirl ; with two smaller, closer rows, one just below the suture. 



336 MAZATLAN UXITAITES 

the other just below the periphery, so as not to be seen in the 
spire ; and another, smaller still, round the base. The labrum 
is distinctly three-cornered between the canals ; anterior canal 
not quite so long as in C. f. mediolseve, and rather more curved ; 
surface less glossy; shape less slender. Only four perfect 
specimens were found, but fragmeuts and young shells appear- 
ed in the Spondylus washings. The young resembles the adult, 
but with the tulaercles semicostal. One of the specimens from 
S. W. Mexico is of a prevailing blackish brown. Long. 1"04, 
long. spir. "7, lat. "45, div. 35°. 
iZVzi.— PTaboga; very rare; C. S. ^(frt?M.s.—S. W. Mexico : 

do. P. P. C— jNIazatlan ; extremely rare ; L'pool Col. 

Tablet 1588 contains 2 very young specimens, 1 adolescent, 
and 1 adult. 

Tablet 1589 contains an immature specimen, which comes 
nearer to this species than to any other. It has the general 
aspect of C. maculosum, but is not like the young of that 
species. The upper whirls resemble those of C. uncinatum ; 
but on the last whirl the tubercles are almost wholly obsolete, 
and the surface generally is granulose. The aperture also is 
much longer in proportion. Long. "65, long. spir. '38, lat. "22. 

384, Cebithiuh , sp. ind. (a) 

Tablet 1590 contains a young sp. (and an imperfect one 
much younger,) measuring '44 by '22, resemblmg the shell on 
tablet 1589 in the general style of sculpture, but without the 
medial tubercles on the upper whirls, and with the canal long 
and straight. It has faint semi-costal tubercles below the 
suture, and finely grauulous spiral stria? over the whole surface. 
It may possibly be a variety- of C. famelicura. 

Ba6.— Mazatlan ; 2 sp. young ; L'pool Col. 

385. Cerithium albolibatum, n. s. 

C. t. conica, turritCi, alba ; anfractibus compadis, plus 
minitsve subcoiwcxis ; Ih'is spi)'alibus valde expres^is eincta ; 
iii — y, in spird monstrantibus, quarum una vel duo interdum 
majores ; costas tran.fversas, undulatas, subobsoletas superanti- 
bm ; aperturd subquadratd. 

The sculpture consists of fine spiral bars with well defined 
interstices traveling over obscure transverse ridges, which do 



MAZATLAN UNIVALVES 337 

not appear in tlie earliest wliirls. The outlines are more or 
less convex, according to tlie prominence or othervnse of par- 
ticular keels. None of the specimens were mature, but no 
species has been found resembling it. The smallest sp. with 
5 whirls, measures '032 by '023. The largest, long. '122, 
long. spir. '075, lat. "067, div. 32". 

Hah. — Mazatlan ; 10 sp. off Chama & Spondylus ; L'pool Col. 
Tablet 1591 contains 4 sp. of different ages. 



386. Cebithium , sp. ind. (7).J 

Tablet 1592 contains an imperfect specimen, closely resem- 
bliug a "West Indian species. It is of an orange brown, with 
not numerous radiating tri-tuberculous costae. 
Sab. — Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 

387. Ceeithium STEECtrs-MrrscAErM, Val. 

' Rec. Ohs. Siimh. Sf Bonpl. vol. ii. p. 278, 
= Cerithium irroratum, Gould, Proc. Bost. Soc. Nat. Sist. 1849, 
p. 11^:— Exp. Shells, p. 61.— C. B. Ad. Pan. Shells, p. 154. 
no. 200. 
Cerithium oceUatum, Mice, in Zeit.f. Hal. 1850, p. 178, no. 40.— 
Sow. Thes. Conch, sp. 69, pi. 179, f. 59, 77.— (?Non C. ocella- 
timi, Brug. no. 43 : — Lam. An. s. Vert. vol. ix. p. 303, no. 30.) 
Sowerby strangely unites to this species the C. interruptum. 
which he attributes to Gould instead of to Menke, and to 
which it has no resemblance. Brugiere's is probably the 
African sheU, specimens of which are in the Br. Mus. from 
Madagascar. They most closely resemble the Pacific species, 
and may hereafter be proved identical. Qf the very numerous 
specimens sent of this shell, extremely few were quite adult, 
and very few young. In its ordinary state, it has a Pirenoid 
aspect ; and the entire freedom of the specimens from the 
usual accretions, the erosion of the apical whirls, and the dark 
hue, would liave led \is to consider it a brackish water shell, 
were it not for the contrary testimony'of Prof. Adams. The 
spire has one row of stout tubercles, but there are no gi-anules. 
The mouth is generally of a lustrous black, usually broadly 
notched at the base ; when adidt, rounded, with labial callosi- 
ties bounding the notch and the short posterior canal. From 
Sept.m>Q. Jjr 



338 MAZATLAN TT>-I VALVES 

the different development of the tubercles on the same whirl, 
the axis has occasionally a bent appearance. Gould's type 
appears to have been nibbed smooth and faded. The opercu- 
lum is not large for the shell, and closely resembles that of 
C. maculosum. The nucleus however is not sunken ; the 
surface is not minutely striated, the outer margin is irregularly 
indented, and the markings of the muscular scar are coarser. 
The upijer whirls are few in proportion, with the same diver- 
gence as the adult. Long. 1"4, lotig. spir. '8, lat. '66, div. 40*. 
Sah. — Acapulco, Humboldt Sf Bonpland. — Panama & Taboga ; 
at and above half tide level ; mostly in the margin of water 
left in the rocks by the tide ; very common, C. B. Adams. — 
Gulf of California and Galapagos, Sowerby, (Mus. Cuming.) — 
S. W. Mexico, P. P. C— Mazatlan ; abundant ; L' pool Col. 
Tablet 1593 contains 7 sp. different ages, elongated. — 1594, 
8 sp. do. broader. — 1595, 3. sp. adult ; of which one (dead) has 
marine attachments. — 1596, 2 sp. lob-sided. — 1597, 2 do. pale 
state. — 1598, 1 sp. with operculum. — 1599, 1 sp. with mended 
fractiire.— 1600, 2 sp., one with Balanus, the other bored by a 
Proboscidean ; extremely rare. — 1601, 9 opercula. 

388. Cekithium intebeuptum, Mke. 

Cerithium interruptum, Mke. in Zeit f. Mai. 1850. p. 178. 

no. 41. — C. B. Ad. Pan. S/iells, no. 198, p. 153.— (Non 

Cerithium interruptum, Lam. An. s. Vert. vol. ix. p. 328, 

no. 1. Fos. Grignou.)* 

? + Ceritliium , sp. ind. C. B. Ad. loc. cit. no. 199. 

Comp. Cerithium (Tympanotonus) Galapaginis, A. Ad. in Soiu, 

T/ies. Conch, p. 869, no. 85, pi. 182, f. 155-6. 

Tllis species agrees exactly with botli the figure and the 
diagnosis of C. Galapaginis, but that shell is classed with Tym- 
panotonus, with which this has no coimection. It begins -n-ith 
three smooth whu'ls, which soon fall off: then a few in which 
the sculpture is wholly in spiral lira?, of which one just above 
the suture is stronger, angulatiug the periphery ; at this stage 
the base is scarcely notclied, and the shell closely resembles 
Trichotropis : afterwards the angular ridge subsides, the spiral 
lines become granulose and the whirls somewhat rounded. 

• Should this imperfectly characterized shell prove to belong to the same genas, 
Menke's nnmo must be altered. II" C. G.ilapagiuia be identical, that may h» 
retained. If not, it may, according to custom, take the name of C. Meukei. 



MAZATLAN UNIVALVES 339 

When adult, the canal is very short, and the labrum slightly 
lirate within. Colour of a prevailing blackish brown, (brown 
in the mouth.) variouslj' dotted and marked with white. The 
operculum is very minutely granular, and closely resembles 
that of C. maculosuin on a small scale. It differs from that of 
C. stercus-muscarum in being of a lighter colour, thinner, with 
the spiral part larger in proportion, margin more indented, 
muscular scar smaller, scarcely marked. The smallest specimen 
measures "035 by "027. The smallest adult, '45 by '2. The 
largest, long. '6, long. spir. "35, led. "28, div. 30°. Tliis is con- 
siderably larger than Menke's specimen ; but many of Prof. 
Adams' were an inch long, and of Cer. no. 199, 1'2 long. 
Sab — Mazatlan ; rare ; L'pool Col. — Taboga and Panama ; 
extremely common, on and under rocks and stones, between 
half- tide level, and low water mark of neap tides ; C. B. Ad. 
Tablet 1602 contains 3 sp. extremely yoimg, and an adult 
with the operculum. — 1603, a series of 7 sp. of different ages. — 
1604, 2 opercula. 

Genus VEETAGUS, Klein. 

H. 4* A. Ad. Gen. vol. i. p. 285. Siphonal canal strongly 
recurved ; columella plaited : opercidum as in Cerithium. 
(teste V. gemmatus, non teste Ad. fig.) 

389. Vebtagus gemmatus, Hinds. 

Cerithium gemmatum, Hinds, Voy. '&ulph. Moll. p. 27, no. 104, 
pi. 11, f. 5, 6.— C. B. Ad. Pan. Shells, p! 152, no. m.—Smc. 
TJies. Conch, sp. 17, pi. 177, f. 41. 
Vertagus gemmatus, H. Sf A. Ad. Gen. i. 285. 

This shell is very constant in its characters ; presenting a 
sharp, straight outline, and a sculpture consisting of 3 rows of 
nodules, (of which the upper is the larger,) with a double 
spiral lino between. The nodules are but slightly developed 
in the young shell. There are numerous small varical ridges, 
but only two principal ones, at the aperture, and at about two- 
thirds of the last whirl. The siphonal canal in the adolescent 
shell is short, and hut slightly recun-ed : afterwards longer 
and much bent. The posterior canal is thick, but with only a 
slight groove. There is no parietal knob distinct from the 
canal, and the columeUar plait is very slight and sunken. The 



^10 MAZATIAN UNIVALVES 

operculiun is on the same plan as in tlie Ceritliia (proper) ; but 
is larger in proportion, tkin near the margin, rather concave, 
with the spiral part saucer-shaped, bounded by a raised mar- 
gin ; outer surface minutely granulated, more conspicuously 
than in C. maculosum ; muscular scar small, with very few 
undulating lines ; remainder of inner surface extremely glossy. 
The smallest adult is 1'14 long ; the largest measures long. 1'45, 
long. spir. lb, lat. '5, div. 25". 

HalL. — Panama; in sandy mud, 2 or 3 — 7+ fm. ; Hinds. — 
Taboga ; very rare ; C. B. Adams. — Mazatlan ; common : 
L'2}ool Sf Havre Coll. 

Tablet 1605 contains a series of 5 sp. shewing the formation 
of the adult mouth. — 1606, 4 sp. adidt, large and small. — 1607, 
7 sp. colour varying from light spotted, to uniform brown red. — 

1608, 5 sp. shewing different positions of penultimate varix. — 

1609, 5 sp. with irregularities of growth. — 1610, 2 sp. with 
opercula in situ, of which one is abnormal. — 1611, 1 sp. with 
operculum cut-off from the dead animal within. It is altogether 
abnormal, irregularly formed of concentric elements, deeply 
indented, and sculptured occasionally with a V pattern, with- 
out granules. It may be the result of the same injuFy to the 
shell which fractured the moiith and destroyed the upper 
whirls. — 1612, 4 normal opercula. 

390. Vebtagus sp. ind, , 

Tablet 1613 contains a fragment, of Cerithiopsoid aspect, but 
with a distinct columellar plait. The whirls are short, numer- 
ous, subquadrate, A^Tth two rows of coarse broad tubercles. 
Hah. — Mazatlan ; 1 sp, off Spondylus ; L'pool Col. 

Gekus TEIFOEIS, Desk. 

Enc. Meth. ii. p. 1053. l^m.— Phil. Handh. Conch, p. 166.— 

H. ^' A. Ad. Gen. vol i. p. 287. 
Cerithium, pars, auct. 

Shell reversed ; canals sometimes tubular ; opereidum orbicu- 
lar, few- whirled This genus appears rare on the W. American 
'■oast, from which there is not one among the many species 
Ic-scribed by Hinds. Prof. Adams has described tliree, from a 
r,\\ P;iiiama specimens, which are here adopted with great 



MAZATLAN UNIVALVES 



341 



1 



doubt, simply because the Mazatlan sbells were not numerous 
enougli to oppose, wliile they did not confirm, his arrangement, 
AVhUe in Cerithiopsis, the sculpture is tolerably constant, in 
these, as in the British species, the rows of nodules and the 
convexity of the spire outlines vary in arrangement on the 
same specimen according to age. The basal sculpture does 
not appear in the young shell. 

391. TeIFOEIS ALTEENATtJS, C B. Ad. 

Pan. Shells, no. 207, pp. 158, 310. 

Shell with the first 7 whirls transparent, light horn-coloured ; 
the first two smooth, then with numerous radiating lines, 
crossed by first one, tben two, then thre? spiral ridges, which 
gradually become nodidous. Then of a purplish brown, for 
many whirls with two rows of stout, lighter-coloured nodules. 
Between these a fine line appears which gi-aduaUy develops 
into first a smaller and at last an equal sized row of nodules. 
Below are one keel on the periphery and two on the base. 
The colour changes to whitish on the lower portion of the later 
whirls. The shell is comparatively large, a fragment measur- 
ing "OS across. A specimen with 9 normal whirls measures 
long. "17, long. spir. '14, lat. '055, div. 20". 
Sah. — Panama, 5 sp. C. B. Adams. — Mazatlan ; portions of 

8 sp. ofi" Spondylus ; L'pool Col. 

Tablet 1614 contains a very young sp., a perfect adolescent 
one, and a fragment of an adult. 

392. Teifoeis inconspicuus, C. B. Ad. 

Pan. Shells, no. 208, pp. 159, 310. 

Shell in sculpture closely resembling T. altematus, but much 
smaller ; with the nuclear whii'ls shorter in proportion, light 
coloured onlj^ at the apex, developing the nodules and the dark 
colour earUer and more gradually. Colour dark throughout : 
the last two whirls with 3 complete rows of nodides. Anterior 
spiral ribs larger, that on the periphery sometimes sbghtly 
scidptured. A specimen very perfect at the mouth but with 
the apex deficient, measures long. '15, long. spir. '115, lat. "05, 
div. 18«. 
Hah. — Panama ; 16 sp. under stones near low water mark ; 

C. B. Adams. — Mazatlan ; 12 sp. more or less complete, off 

Spondylus and Chama ; L'pool Col. 



S42 MAZATLAN TTNITAIiYBB 

Tablet 1615 contains a very young sp. : thp, adult above 
measured ; a fragment between tke two, and a'aother shewing 
a curiously mended fracture. 



393. Teifoeis Pinfeequens, C. ^. Ad. 
Pan. Shells, no. 209, pp. 159, 310. 

A few shells are kept separate (tiil more specimens are 
obtained) as they seem to differ from Tr. inconspicuus in hav- 
ing the apical whirls scarcely sculptrired, but soon adopting the 
permanent type. Prof. Adams' species is only distinguished 
by the number and strength of the three rows of nodules. 
!Jfone of the Mazatlan forms have these so large as in the 
British shell. A specimen with 9 normal whirls measures 
long. '18, long. spir. "135, lat^ '065, div. 20'^. 
Hah. — Panama ; 2 sp. C j5. Adams. — ? Mazatlan ; 6 sp. off 

Chama and Spondylus ; L'pool Col. 

Tablet 1616 contains a young and an adult specimen. 

Genu.', CEEITHIDEA, Sicains. 

JS. Sf A. Ad. Gen. vol. i. p. 292 :— v. A. Ad. Monogr. in Prot. 
Zool. Soc. 1854, p. 83. 

Cerithium, par8, auct. Shell light, transversely ribbed, gene- 
rallj- with a widely expanded mouth, rudimentary siphonal 
notch and decollated apex. Oijerculum multispiral. Animal 
living iu brackish mud (Nuttall), or out of the water on 

twigs.* 

394 Ceeithidea Montagnei, D'Orb. 

Cerithium Montagnei, D'Orb. Voy. Am. Mer. Moll. v. 443, 
pi. 63, f. 3, 4. — liien,. Icon. Couch, p. 99, pi. 30, f. 1. — Sow. 
Thes. Conch, p. 888, sp. 171, pi. 186, f. 28^1-6.— Jtf/lr. in Znt. 
f. Mai. 1850, p. 178, no. m. — B. M. Cat. U Orb. Moll. 

* Clark CMnll. Test. Jfar. lir. p. 305^ in accordance with a habit of generaliziDg 
tor the world from the Mollusks of the South Devon fauna, surmises that all 
shells witl) multispiral opercula belong to hermaphrodite animals, and shoula be 
separated from those of paucispiral elements. If so, Cerithidea must be sep.ir- 
ated from Cerithium, Modulus from Littorina, Aletes from Siphoniom, Torinia 
from Solarium, Adamsiella from Cyclostoma, Melanoides from Melania, Skenea 
from Bissoa, Valvata from Paludina, &c. Mr. Clark himself unites the multispiral 
genera Bittium and Skenea to the paucispiral Bissoa. 



MAZATIAN UNIVALVES 343 

no. 374, p. ^^. — Eyd. Sf Soul. Voy. Bon. pi. 39, f. 6, 7 :— 

B. M. Gat. p. 34, no. 188. 
Cerithidea Montagnei, Mon. loc. cit. p. 83. 
= Cerithiiim Eeevianum, C B. Ad. Pan. Shells, no. 205, 

pp. 156, 310. 
Comp. Ceritliiimi pulclirum, C. B. Ad. loc. cit. no. 204. 

That the Mazatlan shell is identical Math C. Eeevianum, and 
vnth. D'Orb.'s species, is evident from a comparison of tj'pes. 
It is possible that Sow. is right in uniting also the C. pulchmm. 
But iu aifihating the Chiaa species C. Fortunei, A. Ad. (Mon. 
1. c. no. 20) and C. LargiUierti, Phil. (Zeit. f. Mai. 1848, p. 20, 
no. 83,) the latter as the young of the S. American, he displays 
a judgment only surpassed in singularity by that of Dr. Gray, 
who calls this species "only a variety of C. varicosum without 
varices," (B. M. Cat. loc. cit.) Kiener's figure is not charac- 
teristic ; nor was B'Orb.'s sufficiently accurate for Prof. Adams 
to recognize the species. 

None of the Mazatlan shells are so broad in proportion as 
C. pulchrum, C. B. Ad., nor possess its sculpture. This is stated 
to have 40 ribs on each whirl ; Mr. Cuming's type however has, 
as the spire ascends, about 40, 31 and 26 respectively. It differs 
in its regular varices, 240" distant, and in the spiral stria, one 
of which is conspicuous to the top of the non-decollated spire. 
The continuity of the labrum and labium, by which it is 
further distinguished, depends on age, and is equaled in the 
typical form. If a variety, it is a constant one, as Prof. Adams 
found 125 specimens, liviug with the other species. 

The Mazatlan specimens of C. Montagnei vary considerably 
in the elongation and divergence of the spire, in the number 
and strength of the ribs, and ki the amount of spiral sculpture. 
In the upper whirls the ribs are comparatively distant, sharp, 
and never tuberculous. On the last whirl they are often very 
close (sometimes with a sudden change,) sometimes nearly 
obsolete, sometimes spirally subnodulous ; varying from 26 to 
about 48. There is always a raised line continuing the suture, 
(very rarely visible in the suture of elongated specimens,) and 
numerous spiral striae round the base. The surface under the 
microscope is often most minutely corrugated ; and the epider- 
mis, which is tliin and deciduous, is spirally striated, or striato- 
cormgated. No varices are ever seen on the spire ; ^and it is 
onlj'' a very rare accident if one other is seen besides the 
terminal one. The labrum is widely reflected, often in layers ; 
and in the adult there is always a considerable thickening of 



3M MAZATLAN UNIVALVES 

the columellar lip. The apex is always more or less decollated : 
fresh septa are made within ; and the unused portion left to 
drop oflF or not according to circumstances. The shell is never 
incrusted. The operculimi has about 15 whirls, with a verj- 
thin loose edge ; it is slightly rugulose and concave externally, 
and very glossy within. The smallest of the adult specimens 
measures long. 'S8, lo7iff. »pir. '6, lat. '4., div.2o°. 

The broadest (7 whirls) „ I'SS, "„ '9, „ '74, „ 28". 
ThenaiTowest „ IS, „ -92, „ -52, „ 23". 

These measurements are exclusive of the labrum, which 
measures in one specimen lot. '12, alt. '24. 
Sab. — Guayaquil, D'Orhigny. — Panama; not uncommon, half 

buried in muddy sand imder bushes at high water mark ; 

C. B. Adams. — Mazatlan ; abundant ; L'pool ^ Havre Coll. 

Tablet 1617 contains 6 sp. in different stages of growth ; one, 
being broken, shews the extreme thinness of the shell, and 
the axis. — 161S, 5 sp. adult, dwarf state. — 1619, 5 sp. normal 
state. — 1620, 3 do. ribs somewhat obsolete. — 1621, 5 sp. elong- 
ated. — 1622, 1 do. shewing sutural line. — 1623, 2 sp. later ribs 
subgranulous, normal form. — 1621, 3 do. elongated. — 1625. 
1 sp. with two contiguous varices. — 1626, 1 sp. very thick 
varix. — 1627, 1 sp. with operculum in situ, and two separate 
operciUa. 



395. Ceeithidea ? vaeicosa, Sow. var. Mazatlanica. 

Cerithium varicosum, ?Sojo. Gen. f. 5. — Kien. Icon. Conck. 
p. 94, no. 77, pi. 30, f. '2.—?Rve. Conch. Syst. vol. ii. p. 178, 
pi. 226, f. b.—Besh. in Lam. An. s. Vert. vol. ix. p. 321, 
no. m.— B. M. Cat. UOrh. Moll. p. 43, no. 373. — &?c. 
TJies. Conch, p. 887, sp. 169. pi. 186, f. 280-2.—.? Val. Bee. Obs. 
vol. ii. p. 282. 

Cerithidea varicosa, 2fon. loc. cit. p. 83. 

= Cerithium validum, C. B. Ad. Pan. Shells, no. 206, pp. 157, 
310. 

C. t. "C.varicoscB, Sow." simili; sed minore, gracili, unicolore, 
atro-fusc& ; anfr. ultimis haud subito crescentibu^ ; columelld 
vLr tortu^sA ; labia haud incrassato ; costiilis .tpiralibus, ar\fr. 
penult, plerumquc iv. (iii. — v.), liras transversas parum arcua- 
tas tran^euntibus, ad interstitia nodosis; varicibus valde irregu- 
luribus. 



MAZATLAN TTNIVALVES 345 

Comp. C. sacrata, Gould, Exp. Shells, p. 60 : ( = C. Calif ornica, 
Nutt. ms. — Var. = C. fuscata, Gould ms. teste Nutt.) Hob. — 
Upper California. 

Comp. Cerithium (Potainides) Hegewischii, Phil, in Zeit. f. 
Jlfa^. 1848, p. 19, no. 81. r'-HaJ.— Mexico, ?ubi.) 

Desk. & C. B. Ad. both doubt the identity of Sow.'s and 
Kien.'s species. The Mazatlan shells scarcely accord with 
either, and may prove distinct. The genus is not yet Trell 
understood. Sow. imites to this Phil.'s species, which is pro- 
bably au allied form from the "West Indies ; also C. iostoma, 
Pfr. (?ubi) ; also C. helicoide, "the narrow variety without 
varices," C. B. Ad. (?ubi) ; as well as (rightly) C. validum, 
C B. Ad. "Shells o^ Jamaica."* 

The Mazatlan species scarcely agrees with the S. American 
shells in D'Oi'bigny's collection ; and have much more the 
appearance of the variable Californian species, C. sacrata, 
which however has much fainter spiral and stronger transverse 
scidpture. It most closely resembles a W. Indian species, 
which is probablj^ that intended by Philippi, but difiers in its 
uniform dark colour. The scarcely varicose forms are known 
at once from the dwarf variety of C. Montagnei by the strong 
spiral sculpture, even on the upper whirls, the subquadrate 
aperture, and the absence of thick labial deposit. The surface 
is scarcely corrugate ; epidermis rather thick, rough and 
deciduous. The operculum closely resembles that of C. Mon- 
tagnei, but is slightly less concave, and somewhat larger in 
proportion. Occasionally cup-shaped bodies are found on it, 
which look like the remains of egg-cases. It generally measures 
about "95 by '35 ; an extraordinarily large one measures 
long. 1'36, long. spir. I'd, lat. (sine var.) "46, div. 20°. 

Tablet 1G28 contains 5 sp. in various stages of growth. — 1629, 
3 do. intervarical state.— 1630, 4, do. solid, light mouth.— 1631, 
3 do. form more elevated. — 1632, 5 normal state.— 1633, 5 do. 
varices strongly developed. — 1634, 3 do. varices scarcely deve- 
loped. — 1635, 2 sp. varying in sculpture. — 1636, 2 do. mended 
after fracture. — 1637, 1 sp. with operculum in situ ; and 3 
separate opercula, one of which is scared}' spiral (? through 
accident). 

• The inaccuracy with which the labours of Prof. Adams are quoted or ignored 
by yXv. Sowerby, Jan. may be co-ordinate with the execution of the remainder of 
the Monograph, but scarcely does justice to the honoured name which the author 
inherits. 



346 mazatlan ttnivalte8 

Family LITORINIDJE. 

Gentjs LITOETNA, Fer. 

Littorina, Fer. Tail. Elem., 1822, p. 10, (a Uttus, poet.) et auct. 
Litorina, Phil. Handh. Conch, p. 175, (a litus, norm.) 

If the British species of this genus, which are living in 
extreme profusion within reach of naturalists, are not yet 
satisfactorily ascei'tainccl, it is not to be expected tliat those 
from foreign shores should be more favourably situated. Re- 
peated and close examination of many thousand specimens 
from Mazatlan have involved the necessitj^ of joining two of 
Philippi's species. I have therefore dedicated to him, (in 
remembrance of his accurate Monographs of this and many 
t)ther difficult genera, and especially of his great work on the 
Mollusca of Sicilj^) a species which the necessities of the shells 
seemed to require, but which may hereafter, with more copious 
materials, share the same fate. 

Section A. Melaraphe, pars, S. Sf A. Ad. Gen. vol. i. p. 314. 

396. LiTOEINA CONSPEESA, Phil. 

Abhild. pt. ii. pi. 4, f. 14.— C. P. Ad. Pan. Shells, p. 172, 

no. 234.— (Melaraphe c.) H. Sf A. Ad. Gen. i. 314. 
+ Litorina x>uncticidata, Phil, loc. cit. f. 15. — C. B. Ad. loc. cit. 

p. 176, no. 241.— (Melaraphe p.) S. Sf A. Ad. loc. cit. 
= Litorina modesta, Mke. in Zeit.f. Mai. 1850, p. 164, no. 9 : — 
(nou Phil. loc. cit. pi. 6, f. 12: — P/w. Zool. Soc. 1845, 
p. 141 :—Midd. Mai. Ros. pt. ii. p. 66, no. 9, (Sitcha & i!^ew 
Albion, Barclay) : — H. Sf A. Ad. loc. cit. p. 313. 
The ordinary state of the species varies between the extremes 
described by Phil, but comes nearer to L. puncticidata. The 
name L. couspersa is however retained, as being that by which 
the species is generally known, and most distinctive in deriva- 
tion, there being already a L. pimctata. Prof. Adams, while 
acknowledging that the two species approximate, is able for 
the most part easily to distingmsh his 400 specimens. The 
thousands that were sent in the oMazatlan collection not only 
offer intermediate forms, but run so gradually into each other, 
as not to allow of specific separation. 

The species is known by its white, or dirty yello\yi8h colour, 
often dotted, especially in the young shell, with light purplish 



MAaATLAN UNIVALVES 347 

brown ; (not with red as in the Sitcha analogue, C. modesta ; 
which it so greatly resembles in general form that Mice, not 
unnaturally mistook them, but which is put in another sub- 
generic group by Messrs. Adams.) The shape varies from a 
type even more inflated than L. pimeticulata, Phil, to one 
more elevated than his L. conspersa, with every gradation 
between. The surface is either sculptiired with prominent 
(though not sharp) ribs, with very broad interstices ; or with 
smaller and very close ribs, with narrow interstices : or else 
the interstices degenerate into fine Unes cut on the smooth 
surface of the shell, which is tlien somewhat glossy ; or (in 
the young state) it is quite smooth and polished. The columella 
is much excavated, even in young shells. The mouth is gene- 
rally of a rich, lustrous brown within, more or less in bands, 
with dots inside the labrum ; but sometimes it has only the 
yeUow of the exterior more developed. The nuclear whirls 
are of a purplish brown, (sometimes light) of chalcedonic tex- 
ture as in Terebra, and very rarely eroded. The operculum is 
very regular in growth, with the spire well defined ; outside 
with very uTegular lines of growth ; inside with the muscular 
scar beautifidly striated spirally. This can be seen by trans- 
mitted light, and at once separates it from the next species. 
The young shell is frequently angulated at the base ; and an 
unusually large rib often marks the peripherj^ in the adult. A 
swollen sp. measures long. '6, long. spir. "24, lat. "46, cliv. 80". 
An elongated sp. „ 7, „ -37, „ -43, „ 50". 

Huh. — Real Llejos, Rinds. — Taboga and Panama ; common, 
chiefly on large fragments of rock at high water mark : 
C. B. Adams. — Mazatlan ; extremely common ; L'pool Sf 
Havre Coll. 

Tablet 1638 contains 7 sp. white, very ventricose.— 1639. 9 
do. rather less, (answering to L. puncticulata.)— 1640, 7 do. 
ordinary state.— 1641, 7 do. flattened ribs.— 1612, 7 do. more 
elevated. — 1643, 8 do. form L. conspersa, PJiil. 

Tablet 1644 contains 7 sp. very much elevated, yellowish.- 
1645, 11 do. series from young state "18 by '17.— 1646, 6 do. 
less elevated. — 1647, 8 do. whirls rounded.— 1648, 7 do. usual 
shape. — 1649, 7 do. rather flatter. — 1650, 7 do. ventricose. 

Tablet 1651 contains 3 sp. keels distant. — 1652, 4 do. keels 
very close.— 1653, 3 do. keels somewhat irrcgidar, as in Purpura 
lapillus.— 1654, 4 do. nearly smooth. — 1655, 4 sp. abnormal 
growth.— Many of tlie above retain their opercula : tablet 1656 
contains 9 separate ones. 



348 MAZATtAN UNIVALVES 

397. LiTOEINA ASPEKA, Phil. 

Proc. Zool. Soe. 1845, p. 139 : —Ahbild. pt. ii. pi. 4, f. 13.— 
]\fke. ill Zeit. f. Mai. 1847, p. 178, no. 2 : do. 1850, p. 163, 
no. 8.— C. B. Ad. Pan. Shells, p. 170, no. 2Z2.—??Midd. Mai. 
Ros. pt. ii. p. 66, no. 10. 
Melaraphe aspera, IE. ^ A. Ad. Gen. 314. 

Besides the natural doubt tliat an essentially tropical shell 
extremely common at Panama, less so at ]\Iazatlan, and not 
found at all on the Californian coast bj' the accurate observer, 
Mr. Nuttall, (where it is replaced hj L. planaxis,) should 
reappear in the Boreal region of Sitcha, the description of 
Middendorflf by no means accords with Philippi's shell. The 
Kussian shell is "crassa, luieis nigricantibus obliquis picta, anfr. 
parum convexis," and is said to resemble L. ziczac andL. zebra. 
The evidence therefore appears to be very unsatisfactory, on 
which Prof. Forbes, in his Zoological Map, gives this species 
as characteristic of the Oregon fauna. A very different shell 
from Pernambuco {J. P. G. Smith) is also given in the B. M. 
as the L. aspera, Phil. 

The Mazatlan shell is (for the genus) rather thui, and toler- 
ably constant in characters. It is readily known when fresh 
from L. conspersa by the dark hue and sharp, distant ribs. In 
shape it goes through the same changes as its congener ; but 
in sculpture and colour is much more constant. The ribs are 
sharp, -with very broad concave interstices, are somewhat rough- 
ened by lines of growth, and are beautifully tinted, in ill-defined 
spots, with umber. The young shell (as Mke. states) has a 
chalcedonic apex like that of L. conspersa, below which it has 
generally a slate coloured band. The spots also are more de- 
fined, and run into lines. They were provisionally distinguish- 
ed by ]\Ike. as L. apicina. At this period the ribs are closer 
and flattened, but still much more conspicuous than the cor- 
responding stage of L. Philippii. The apex is commonly eroded 
in the adult. The colour within resembles that of L. conspersa, 
but is gencraUv darker. The base of the young shell also 
agrees in being often keeled or angulated. The operculum is 
rather broader than in that species, with the thin trasparent 
edge less defined. Inside the nucleus is raised, and is rarely 
seen to display the spiral elements. The muscular scar is not 
furnished with spiral stria:, but is irregularly roughened with 
minute knobs and strias of growth. An unusually compact 
specimen measures long. '7, long. spir. '31, lat. '5, div. 70". 
An elongated sp, „ '64, „ '32, „ '4, „ 50". 



MAZATLAN XJXIVALTES 349 

Hah. — "Sitclia, Mexico aud San Salvador," Philippi. — Sitcha 
and NeTT Albion, Barclay, (teste Midd. sed v. supra.) — 
Panama & Taboga ; extremely common on ledges and large 
fragments of rocks at or above high water mark ; C. B. Ad- 
ams. — Mazatlan ; common ; Melchers. — Do. not uncommon ; 
L'pool Sj BLavre Coll. 

Tablet 1657 contains 6 sp. compact form.— 1658, 6 do. nor- 
mal shape. — 1659, 6 do. more elevated. — 1660, 6 do. elongated. — 
1661, 5 do. much elongated. — 1662, 4 sp. ventricose. — 1663, 
2 do. ribs distant. — 1664, 4 do. ribs close. — 1665, 2 do. abnormal 
growth. — 1666, 6 young sp. ribs very fine. — 1667, 6 young sp., 
P. apicina. Mke. — 1668, 6 do. elevated, approaching L. Philippii. 
— 1669, 3 separate opercula (others in their shells.) 

Tablet 1670 contains 3 very young Litorinpe, the smallest 
'03 by "024, the largest "088 by "055, probably belonging to 
this species, but too young to identify with confidence -without 



398. LiTORiNA Philippii, n. s. 

L. t. inter "L. asperam" et '' L. zic-zac" intermedia ; paroa, 
compactd, interdum elevata, ■plerumque gibhosd ; anfr. suhplan- 
atis, ad basin anc/ulaiis ; colore livido, seu olivaceo-livido, 
olivaceo-Juscd oblique strigaid ; lineis irregulanhus, interdum 
zic~zae-formibus, interdum interriiptis, tesselatis : totd super- 
fioie nitentiore, sulcis suhdistaniihus subimpressis ornatd ; colu- 
mella excavatd ; intus fused, margine acuta labri plus minusve 
lineato ; nucleo plerumque eroso ; operculo tenuiore, laiiore ; 
intus nucleo vix elevato ; imp. muse, minutissiine scabro, lineis 
incrementi conspicuis, suiurd spirali liaud celatd. 

This unpretending little species may be the L. aspera, var. 
'"more slender, sculpture reduced to spiral imi)ressed lines" 
of Prof. Adams. It may also form a part of the L. apicina of 
Menke ; but as its usual character is just the contrary of his 
diagnosis, being almost always eroded even in very young 
specimens, it would havfe been scarcely truthful to retain the 
name which he provisionally gave, apparently to the young of 
L. aspera. The markings in this species, (which iu L. conspersa 
are purplish brown dots, and in L. aspera umber spots) are 
olive brown, almost always in slanting lines more or less 
interrupted ; and when broken up into dots, these are always 
square, tesselating the spaces between the spii-al lines. It is 
Oct. 1856. gg 



350 MAZATLAN UNIVALVES 

very much more common than L. aspera at Mazatlan ; very 
young specimens of the latter being so rare that I am unable 
to state their exact difference, and some in each series may be 
wrongly placed. The ordinary specimens however are dis- 
tinguished by the flattened form, and faint sculpture. The 
adults have a very different aspect from each other, although 
worn specimens may be confounded. It presents less variation 
of form than either of the other species ; making up for this 
by the multiform patterns of the stripes. The operculum 
closely resembles that of L. aspera ; but appears to differ in 
being more transparent, with the shagreening on the muscular 
scar less and the spiral striae more conspicuous, and the nucleus 
less raised and displaying the spiral element. The ordinary 
size is '4 by "28 ; the smallest is "18 by "12 ; an extraordinarily 
large one measures long. "6, long. spir. '3, lat. '35, div. 50". 

JIab. — Mazatlan ; common ; L'pool Sf Havre Coll, 

Tablet 1671 contains 7 sp. ventricose, resembling the young 
of L. aspera. — 1672, 8 sp. highly coloured, as in L. aspera, jun., 
but of normal shape : in the youngest, the stripes coalesce and 
nearly cover the shell. 

Tablet 1673 contains 7 sp. stripes broad, zig-zag. — 1674, 8 do. 
stripes narrower, hue olivaceous. — 1675, 8 do. stripes inter- 
rupted in the middle. — 1676, 7 do. stripes zig-zag at base. — 
1677, 7 sp. lines very fine, olivaceous. — 1678, 7 sp. stripes not 
interrupted, broad. — 1679, 7 do. narrower. — 1680, 7 do. very 
narrow. — 1681, 7 do. olivaceous. — 1682, 5 do. stripes broken-up 
into tesselations. — 1683, 6 do. markings extremely faint. — 
1684, 7 sp. spire elevated.— 1685, 9 separate opereula (others 
in the shells.) 



399. LiTOKiNA , sp. ind. 

Tablet 1686 contains 2 sp., one young and fresh, the other 
adult and dead, differing from the rest in colour, which is of a 
nearly uniform blackish brown, with faint spiral lines of white ; 
in texture, which is nearly smooth, with a very few extremely 
faint spiral lines near the base ; and in the columella, which is 
not excavated. Long. '5, long. spir. "25, lat. '32, div. 50°. 

ITab. — Mazatlan ; extremely rare ; L'pool Col. 

The same tablet also contains a very youn g shell, measxmng 
07 by '05, more obtuse than the j^oimg of the other species. 



mazatlan ttnivalves 351 

Section B. 

Shell large, Phasianelloid, rather tliin, coloured ; columella 
excavated. Animal amphibious ; often found crawling up trees 
at a considerable distance from the sea ^J)y5o?jJ = Melaraphe, 
pars, S. Sf A. Ad. Gen. vol. i. p. 414: — ?non Melaraphe, 
Muhlfeldt. When convenience requires the subdivision of 
Litorina, this group, included by Lam. in Phasianella, will 
probably be found natural. 

400. LiTOEiNA FASCiATA, Gray. 

Zool. Beech. Voij. p. 139.— S/ei. in Wiegm. Arch. p. 209.— P/w7. 

Abbild. pt. ii. p. 37, pi. 5, f. 1, 2.—Mke. in Zeit.f. Mai. 1850, 

p. 163, no. 7.—C. B. Ad. Pan. Shells, p. 173, no. 236.— 

S. Sf A. Ad. Gen. i. 313. 
+ Melaraphe fasciata, H. Sf A. Ad. Gen. i. 314. 

This very beautiful species, of which but few specimens 
were found, is (as Menke remarks) intermediate between 
L. pulchi-a and L. scabra. The spire is pointed, never eroded. 
When young it has fine spiral strise, and is somewhat highly 
coloured Avith orange and purplish brown in irregular bands 
or dashes. When adult, it is often nearly smooth, with the 
colour evanescent near the labrum. The operculum is very 
thin, with but few turns, and the nucleus not far from the 
middle. Surface not granulose, with rather coarse strise of 
growth. The lai'gest sp. measures long. 1*16, long. spir. '64, 
lat. -95, div. 60". 
Sab. — Tumbez, Peru, Cuming. — Panama ; not uncommon, 

with L. varia, on trunks and branches of small trees growing 

between half tide and high water levels ; C B. Adams. — 

Mazatlan ; very rare ; L'pool Col. 

Tablet 1687 contains the most characteristic specimen, with 
its operculum ; also a very young shell ; and a loose operculum. 



Genus MODULUS, Gray. 

Phil. Sandh. Conch, p. 176.—^. ^ A. Ad. Gen. vol. i. p. 316.— 
A. Ad. Mon. in Proc. Zool. Soc. 1850, p. 203. 

= Monodonta, Swains. = ^lonodonta, pars, Lam. — Shell not 
pearly, generally Trochiform, with a deeply grooved colu- 
mellar tooth. Operculum midtispiral. 



352 MAZATLAN UKIVALVES 

101. Modulus catenulatus, Phil. 

Troclius catenulatxxs, Kiist. Si/st. Conch. Cab. p. 110, no. 122. 

pi. 18, f. i.—MA-e. in Zeif. f. Mai. 1850, p. 173, no. 33.— 

C. B. Ad. Pan. Shells, no. 273, p. 190. 
Modulus catenulatus, H. ^ A. Ad. Gen. i. 317. 
= Modulus trochiformis, P!//d. ^ Soul. Voy. Bonite, pi. 36, 

f. 1—5, pi. 37, f. 25-31 -.—B. M. Cat. p. 23, no. 177. 
= Modulus Carchedonicus, P. P. C. Cat. Prov. : — non A. Ad. 

loc. cit. : nee Monodouta carchedonius, Lam. An. s. Vert. 

vol. ix. p. 175, no. 7, { = T. perlatus, Dillw. = T. unidens, Chem. 

teste Desh. .• = !. tmideng, D'Orh. B. M. Cat. Sagr. Col. p. 21, 

no. 233, pars.) 

The synonymy of tliis little understood genus lias scarcely 
been improved by Mr. Adams' monograpli of the species in 
the Cumingian Collection. The Lamarckian name is there 
assigned to the M. Sayii, Nutt. ms., said to be from "Atooi, 
California." The genus was not found by Nuttall in California, 
and Atooi is in the Sandwich Islands. The Lamarckian 
species, which may be the Caribbrean analogue of this shell, 
T. angulatus, C. B. Ad., or a distinct species, must revert to 
the old Chemnitzian name, M. unidens, teste Desh. 

The Mazatlan shell when adult has the general aspect of 
a Trochus ; the spire being (more or less) elevated, and the 
spire-outlines straight. The spii'e is covered with crowded 
subgranulous revolving strijo ; and the base, which is rarely 
flattened, often much swollen near the very small umbilicus, 
has about 8 rather deeply cut grooves. .Colour varying from 
white to light purplish brown ; generally with the latter in 
dots. Labrum sharp, inside deeply grooved : periphery with 
a very sharp keel, which in young shells, or after fracture, is 
sometimes slightly waved, scai'cely tuberculous. Operculum 
multispiral (not paucispiral, as stated in Ad. Man. loc. cit.) 
w^th about 9 turns, very thin, transparent, edges irrcgidarly 
overlapping, rather concave outside, with the surface most 
minutely graniUose. The shells, though strong, had often 
received severe fractures ; they were sometimes mcrusted, and 
occasionally incommoded by Ostrea conchaphila. Long. '77, 
long. spir. '48, lat. '72, dii\ 70". 
Hah. — Mazatlan ; not uncommon ; L'pool ^ Havre Coll. 

Tablet 1688 contains 1 sp. white.— 1689, 3 do. flattened.— 
1690, 3 do. undulated.— 1691, 1 six ordinary state.— 1692, 3 do. 
flattt'ned.- 1693, 3 do. deep colour.— 1694, 3 do. undulated.— 



MAZATLAN UNITALTES 353 

1695, 3 sp. curiously mended. — 1696, 1 do. supporting 3 speci- 
mens of Ostrea conclaapliila round its base. This, with several 
otter specimens, retains its operculuni. — 1697, 2 separate 
opercula. 

402. Modulus , sp. hid. 

Tablet 1698 contains a solitary and young sbell resembling 
M. catenulatus in outline and tooth ; but with a well developed 
umbilicus, rounded and distinctly tuberculoiis keel, and whirls 
concave above. The colour is prettily mottled witli purpHsli 
brown. It differs from M. disculus iu the small tooth, conical 
spire and concave whirls. Long. "47, long. sjnr. "3, hit. '5, 
div. 80". 
JIab. — Mazatlan ; 1 sp. with M. catenulatus ; L'pool Col. 

403. Modulus disculus, Phil. 

Trochus disculus, Phil, in Kust. Mart. no. 308, p. 242, pi. 36, 

f. U:—Zeit.f. Mai. 1846, p. 51, no. 19. 
Modulus disculus, S. Sf A. Ad. Gen. i. 317. 
= Modulus duplicatus, var. A. Ad. iu Mus. Cum. 
= Modulus dorsuosus, Gould, (ad fid. sp. typ.) Mex. Sf Cal. 

Shells, p. 10, pi. 14, f. 12. 
Comp. Monodonta modulus, Lam. in Kust. 3Iart. no. 307, 

p. 241, pi. 36, f. 11—13. {Hah.—\\. Indies.) 

Known from M. catenulatus by the depressed spire, some- 
what rounded and strongly tuberculous keel, violet-tinted 
mouth, and very deeply cut tooth, with a broad groove on the 
base. The young specimens are imperforate, but the old ones 
have a small umbilicus. It most closely resembles one of the 
W. Indian species. Long. "6, long. spir. *32, lat. '65, div. 110". 

Hah. — Mazatlan, Philippi. — Do. ; 3 sp. with M. catenulatus ; 
L'pool Col. — "Found at AcaiJulco, Col. Jetvett," Goidd. 
Tablet 1699 contains a young and an adult specimen. 



Genus FOSSAEUS, Adanson. 

Fossar, Gray, S//n. 18\D: — Proc. Zool. Soc. 1847, p. 151, 

no. 206, (Forsar, err. typ) 
Fossarus, Phil. Arch. f. Nat. i. p. 42, 1841 -.—Jlandh. Conch. 

p. 173. 



354 MAZATLAN UNIVALVES 

Maravignia, Aradas &f Maggiore, 1842. 
Phasianema, Searles Wood, Crag Moll. 1842, 

Animal with two frontal lobes between the tentacles ; shell 
umbilicated, sculptured, mouth semilunate. 



404. FoSSAEUS TTJBEBOSUS, 71. S. 

F. t. "Fossaro angiilato" simiU, sed anfr. vi., quarum iv. 
iuherosi, rubri, coiwentrice tenuissime lirati, interdum carinati ; 
anfr. ii. normalibus, alhido-fmcis, plus minusve tumentibus, 
carinis et liris plus minusve irregulariter extantibus ; labia 
excavato ; umbiUco et staturd maxime variantibus ; epider- 
mide interdum setosd. 

= ?Trichotropis, sp. 1. P. P. C, Cat. Prov. 
Comp. Adeorbis scaber, Fhil. in Zeit. f. Mai. 1848, p. 129. 
(Sab. — Panama.) 

The three individuals found vary extremely in form, markings 
and umbilicus. They agree however in the remarkable char- 
acter of the vertex, which is like that of (Tuberia) supralirata, 
and is set rather slanting on the body whirls. These are 
either regular, or suddenly bulging, as in the polymorphous 
Dundry fossil, Cirrus nodosus. Sow., and are marked with 
irregular costa?, two or more of which develop into keels. In 
the spreading form the umbilicus is very large ; in the compact 
state very small. A young spreading sp. measui'es '032 by '03, 
div. QOj" ; a larger compact one, long. '043, long. spir. '015, 
lat. -38, div. 60". 

Sab. — Mazatlan ; extremely rare, off Chama and Spondylus ; 
L'pool Col. 

Tablet 1700 contains the two extreme specimens. 



405. FOSSAKUS ANGULATUS, n. s. 

F. t. suhovoided, tenui ; albido-fused, atro-purpureo irregu- 
lariter maculosd ; .<tpird subacidd, anfr. iv. quorum duo nucleosi, 
leeves ; carinis angulatis circiter x'\. quarum duo; tresve extan- 
tiores sunt, striulisque spiralibus creberrimis, ah epidermide 
tenuissime cancellatis, elegantcr exculptd ; nmbilico magno, acute 
carinato ; labro tenui, angulato ; periiremati continuo ; labio 
vix excavato, haud plicate. 



MAZATLAN UNIVALVES 355 

Two specimens of this species were found, differing some- 
what in the prominence of the angular keels. It displays no 
trace of callosity on the pillar lip, and is known at once from 
Isapis maculosa by the acute spire, and the very fine spiral 
strise and keels. The older (worn) specimen measures long. '07, 
long. spir. -025, lat. -063, div. 80". 
Hab. — Mazatlan ; 2 sp. off Spondylus ; L'pool Col. 

Tablet 1701 contains the fresh specimen, almost translucent. 

Subgenus ISAPIS, H. Sf A. Ad. 

Gen. vol. i. p. 320. Part of the diagnosis of this group is 
only of specific value, being founded on the PNarica anomala, 
C. B. Ad. (Contr. Conch, no. 7, p. 109,) from Jamaica. The 
Mazatlan species agree exactly with Fossarus except in the 
eolumeUar plait, which is obtuse and small in I. ovoidea, 
(Narica ovoidea, Gould, Cal. ^ Mex. Shells, p. 7, pi. 14, f. 10, 
"purchased at Mazatlan, Col. Jewett;") and in I. maculosa 
is almost obsolete. A similar structure appears in Purpura 
columeUaris : in Cuma tectiun, it becomes a TurbineUoid fold. 

406. IsAPIS MACULOSA, 11. S. 

L t. suhovoidea, inflatd, tetmi ; albidd, fusco-purpureo macu- 
losa, subnacred; apice planato ; anfr. iii., rapide augentibus ; 
liris spiraUbus validis, extantibus, siibquadratis, circiter s., 
quarum ir. in aiffr. penult, videntur, duceque umbilieum magnum 
entrant; interstitiis tenue cancellatls ; epidermide sublamel- 
losd; peritremati continuo ; labi-o acuto, a liris palmulaio, 
intus sculpturam externam monstrante : lahio vix arcuato, 
callositate mediand, obtusd, inconspicud munito. 

Differs from I. ovoidea in its small size, depressed spire, 
flattened vertex, shouldered whirls, deeply spotted surface (the 
spots being conspicuous even in a very dead shell), scarcely ex- 
cavated labium, and very obtuse deposit, which can hardly be 
seen except in the broken shell. In other respects there is a 
great correspondence. The lustrous hue of the interior is a 
good distinguishing character. Long. "118, long. spir. "038, 
I lat. -112, div. 90". 

I Hab. — Mazatlan ; extremely rare ; L'pool Col. 
I Tablet 1702 contains a beautiful young specimen, "035 by 

'025, and a perfect adiilt. 



356 MAZATLAN UNIVALVES 

407. ?IsAPis , sp. ind. 

Tablet 1703 contains a fragment of a species resembling 
I. ovoidea, but Tritb very numerous fine spiral ribs, with broad 
concave interstices, crossed by transverse ridges most develop- 
ed on tlie x^enidtimate whirl. 
Sab. — Mazatlan : 1 sp. on Spondylus ; I! pool Col. 

Family EISSOID^. 

Gentjs EISSOINA, D'Orb. 

Voy. Am. Mer. 1840, p. 395.— P7t/Z. Kandh. Conch, p. 172.= 
H. ^' A. Ad. Gen. vol. i. p. 327. — Base slightly channeled, 
labrum thickened, operculum neritoid. 

Eissoa, pars, auct. 

408. EissoiXA STBicTA, Mke. 

H. t. alhd, subturritd, solidd, anfractibus ?x., apice ? ,- 

labro incrassato, ad mediam partem producto ; labio parvo, 
reflexo ; columella truncatd ; costis radiantibu.^ subrotundatis, 
in anfractu utroqiie circiter xx., striuUs spiralibus obsoletis ; 
sutiD'd impressd, costis ad apicem co7ittnuis. 

Eissoa strieta, Mle. in Zeit.f. Mai. 1850, p. 177, no. 37. 
Comp. Eissoa fortis, C. B. Ad. Pan. Shells, pp. 178, 314, no. 245. 
Comp. Eissoina pyramidata, A. Ad. 

A single specimen of this shell was found by Mr. Hanley in 
the Spondylus washings. Menke's shell is still larger, measur- 
ing 3'7 byl" lines. Even Mr. Hanley's specimen is very 
much larger than E. Woodwardii, which in general form it 
much resembles, measuring long. '27, long. spir. (apice carente) 
•17, lat. -11, div. 20". 

Hab. — Mazatlan ; extremely rare ; Havre Col. 

Tablet 1704 contains some fragments which seem to belong 
to this species, with an apex resembling that of E. "Woodwardii, 
but larger in proportion ; and a sketch of the unique sheU in 
Mr. Hauley's Collection. 



MAZATLAN UXIVALTES 357 

409. RissoiNA , sp. ind. 

Tablet 1705 contains a very joting shell and a fragment of 
adult, of large size, differing from li. stricta in tlie extreme 
sharpness of the ribs. It appears to be most minutely striu- 
lated transversely. v 

Hob. — Mazatlan ; extremely rare, off Spondylus ; L'pool Col. 

410. ElSSOINA WOODWAEDIT, «. S. 

H. t. mi nor e, elongata, angusta, albidd, interdum alahastro 
simili ; anfr. vii.-yiii. siihplanatis, quorum iii. primi laves, 
tumidiores ; sutura impressd ; marginihus spires excurvatis ; 
costis xii.-xiv. in anfr. utroque an gustis, acutio r ibus ,■ 
Imeis declivibus apicem versus ascendentibus ; a-perturam versus 
scepe crebrioribus ; t. juniore ad basin elongatam evanidis, 
seniore basin subelongatam amplectanlibus ; interstitiis latis, 
concavis, interdum minutissime striulatis, striulis costibus 
parallelis; aperturd normali ; axi t. juniore producta, 
suhcanaliculatd, seniore suhemarginatd, plica seu lined spirali 
nulla ; labio solidiore. 

Comp. Eissoa clandestina, C. B. Ad. Pan. Shells, p. 177, 

no. 243. 
Comp. Eissoa firmata, C. B. Ad. loc. cit. no. 244. 
Comp. Eissoa Bryerea, Mont, in Forbes ^' Saul. Br. Moll. 

vol. iii. p. 149. 

The Mazatlan species (of which about 70 adult specimens 
were found, and as many young and fragmentary,) is very 
ujiiform in its characters ; and is distinguished by its small 
size, shape and distant ribs, (generally 13 on the penultimate 
whirl,) entire absence of spiral sculpture, and most minute 
transverse striulation, which is generally seen in the young 
shell, but very rarely in the adult, and then only under a good 
microscope. In the pseudo-British species, of which even 
Montague's small [?] variety is much larger, the ribs are much 
closer, and the transverse stria; are strong enough to be seen 
in dead specimens. It appears about the size of E. clandestina, 
but agrees better in sculpture with E. firmata. It is not con- 
specific with any of the similar E. or W. Indian species that I 
have been able to subject to the ordeal of the microscope. An 
unusually large sp. of the Mazatlan shell measures long. ' 123, 
long. S2nr. "08, lat. '053, div. "Zi". 
Sab. — Mazatlan ; rare, on Chama and Spondylus ; L'pool CoL 



358 MAZATLAN TJNITAIVES 

Tablet 170G contains a series of 11 specimens of different 
ages, beginning from "027 by '018, and presenting tbe extremes 
of variation. — 1707, 2 sp. alabastrine variety, and as a contrast, 
one with black incrustation ; also 2 fragments to illustrate the 
adolescent and the adult basal sculpture. 



Genus EISSOA, Freminville. 

Bull. Soc. PMlom. 1814, p. 7. 

Loxostoma, Bivon. 1832. — Lamarckia, Leach. — Gonostoma, 
Milhlf. 



411. PElSSOA LIEATA, n. S. 

1 R. t. conoided, alhido-fmca, soUdiore ; anfr. vi., quomm ii. 
primi iumidiores, Icevi ; reliqui planati, eleganter lirati, Ihns 
plurimis (in spird circiter x.J extantibus, interstitiis cBquantihu^, 
quadratis ; sulco latiore circa peripheriajn, suturam superanie ; 
anfr. radiatim obsolete undatis, prope suturam subnodosis ; 
marginibtis spirce excurvatis ; basi subangulato ; aperturd sub- 
ovali, peritremati continuo ; lahro antice expanso : operculo 
soUdiore, corneo, rufo-fusco, semilunato, convexo ; elemeniis con- 
centricis ; nucleo subcentrali, marginem interiorem versus ; intus 
processu conico anteriori prcelongo, extante, costd ad alterum 
marginem decurrente. 

Of this beautiful shell one perfect specimen was found with 
its operculum. This makes its generic position doubtful ; as 
it presents the concentric elements of Jeffreysia and the 
anteriorly projecting process of Eissoina, in conjunction with 
a shell typically Eissoid. The nucleus is projecting, and 
situated about half way between the centre and the inner 
margin. It appears that the entire sculptured layer may be 
abraded ; for a specimen was found (which but for one iu an 
intermediate state woidd surely have been regarded as a dis- 
tinct species) without either lira) or transverse waves, and 
scarcely shewing the sTitural furrow ; but with a smooth surface 
most delicately corrugated transversely. Long. '12, long. 
spir. ■073, lat. -063, div. 25". 

Hah. — Mazatlan ; 9 sp, off Chama and Spondylus ; L'pool Col. 

Tablet 1708 contains the perfect and the abraded specimens. 



MAZiTLAN TJNIVALVES 359 

Gentts ALVANIA, Bisso. 

In this section are deposited certain turrited Rissoidse, with 
tumid whirls. They do not however correspond with the genus 
as defined by H. Sf A. Ad. Gen. vol. i. p. 330. 

Cingula, pars, C. B. Adams. 

412. PAlvania excubvata, n. s. 

?A, t. tenui, turritd, elongatd, purpv/reo-fuscd, pupaformi, 
marginihus spirce excurvatis ; anfr. viii. quormn ii. primi pur- 
pnrei, Imves, apice planato ; dein'ni. tumidiores,bi-seu tri-cari- 
nati ; reliqui subplanati, sculpturd minus expressd ; superficie 
valde irregulariter cancellatd ; costis obtusis, s(spe obsoletis, 
circiter xs.., ad periphcriam evanidis ; Uris spiralibus quarum 
pleriimqtie iii. spird monstrantur, circa basin (injuniore inter- 
dum IcBvem) siibangulatam circiter iii. ; interstitiis haud impres- 
sis, nunc Uris nunc costis superantibus ; aperturd subovali, 
subquadrata ; labro tenui; labia tenuissimo, rimulam umbilica- 
lem vix monsfrante. 

This shell, in its regular growth and markings, reminds us 
of Turritella goniostoma. About 100 specimens were found, 
but most of them were extremely imperfect. Long. "112, 
long. spir. "077, lat. "038, div. 25". 

Sab. — Mazatlan ; rare, off Chama and Spondylus ; L'pool Col. 
Tablet 1709 contains 8 sp. varying in age, colour and sculp- 
ture. In one the sculptured layer is entirely removed, and the 
shell is only known by its shape. 

413. Alvania efftjsa, n. s. 

A. t. "A. excurvato:" simili, sed solidiore, apice acutiore, 
spira regulari, anfr. tumentibus, normaliter cancellatis ; costis 
circiter xx. extantibus, ad basin evanidis, a Uris spiralibus 
circiter xiii, tuberculatis ; interstitiis et suturis valde impressis ; 
ba-si effusd, striuUs paucis axin solidam versus ; aperturd 
oblongd ; labro solido, interdum varicoso ; labio inconspicuo ; 
umbiUco nullo. 

Only one specimen was found of this beautiful species, which 
is distinguished from A. tumida by its very elongated shape, 
and from A. excurvata by the above characters. In sculpture 
it resembles Phos. Lo7ig. "US, long. spir. '077, lat. '042, div. 22". 
Sab. — Mazatlan ; 1 sp. on Spondylus ; L'pool Col. 

Tablet 1710 contains the specimen. 



360 MAZA.TLAN tTNIVALVES 

414. Alvakia tumida, n. s. 

A. t. ventricosd, alho-fusca, solidd ; anfr. v. tumentlbus, 
suhcequaliter cancellatis ; costis haud ohtusis circite)' xxii. trans- 
versis, a liris spiralihiis intersectis, nodosis ; liris vii., quarum. 
iii. spiram transeunt, una umhiUcum satis magnum definat ; 
interstitiis quadratis ; aijertura suhrotundata, lahro varicoso, 
labio tenuiore. 

Differs from all varieties of A. excurvata in its very tumid 
gro'^rth, Timbilicated base, and tMckened lip. Lvng. '057, 
long. spir. '034, laf. '033, div. 40". 
Hab. — Mazatlan ; 2 dead sp. off Spondylus ; L'pool Col. 

Tablet 1711 contauis one specimen. 

415. PAlvania , sp, ind. 

Tablet 1712 contains a wbite, rather solid sbeU, with very 
tiunid whirls and a round mouth. It might pass for a Scalaria, 
but has no ribs ; or for an Aclis, but the apex is dextral. One 
whirl has perished ; the remaining seven measure long. "048, 
long. spir. '03, laf. '027, div. 30". 
Hab. — Mazatlan ; 1 sp. off Chama ; L'pool Col. 

Genus CINGULA, Flem. 
H. Sf A. Ad. Gen. vol. i. p. 334.— Cingula, pars, C. B. Ad. 

416. ? Cingula , sp. ind. 

Tablet 1713 contains a short, broad, white, smooth, rather 
solid shell, with flattened whirls, of Odostomoid appearance ; 
but the apex appears dextral. The poritreme is continuous 
and not plaited. It has five whirls, and measures long. '053, 
long. spir. '03, lat. '033, div. 43«. 
Hab — Mazatlan ; 1 sp, off Chama ; Lpool Col. 

Genus HYDEOBIA, Eartm. 

Sturm, Deutsch. Faun. vi. 5, p. 47, 1821. — Phil. Sand. Conch. 

p. 168.— fit Sf A. Ad. Gen. vol. i. p. 385. 
Leachia, i2?>so, 1826.— Paludestrina,i)'0r5. 1840.— Paludinella. 

Lov. Midd. (? = Paludinella, Ffr.) 
Rissoa, pars, auct. 



MAZATLAN UNIVALVES 361 

417. Htdeobia ulv^, Penn. 

Turbo ulva?, ^Fenn. Br. Zool. vol. iv. p. \i2,.—Mont. Test. Brit. 

vol. ii. p. -ilS.— Forbes Sf Hani. Br. 3Ioll. vol. iii. p. 141. 
Paludinella stagnalis, (Linu.) Midd. Sib. Reise p. 129.— ? = Helix 

stagnalis (prima) Linn. Syst.Nat. no. 1248 : — Sanl. Ii)S. Linn. 

Conch, p. 380. 
Hydi-obia ulvs, S. Sf A. Ad. Gen. i. pi. 35, f. 10, 10a, b, c. 

As the Mazatlan shells, after careful microscopic examin- 
ation, do not oifer the slightest specific difference from the 
British specimens, it did not seem allowable, merely for geo- 
graphical reasons, to impose upon them a new name. Whether 
it be the first H. stagnalis of Linn, as Middendorf supposes, is 
a matter of doubt ; v. Hani. loc. cit. The well known name 
of the English writers is therefore chosen ; and for the syn- 
onyms, the Br. Moll, and Midd. Sib. Iteise may be consulted. 
The Mazatlan specimens were small, measuring long. "1, 
lat. -058. 
Hab. — Eiiropa?an seas, in brackish water, passim. — Caspian 

Sea, JSichicald. — Massachusetts and New York, teste Mid- 

dendorff. — South Coast of Okotsk Sea, on Algae, Middcn- 

dorff. — Mazatlan ; 4 sp. in shell washings ; — L'pool Col. 

Tablet 1714 contains the smallest and the largest specimens. 

418. PHydeobia , sp. ind. 

Tablet 1715 contains a shell resembling H. ulvse, but with 
the apex more prominent, the whirls more swollen, and a spu-al 
raised band running round a fairly developed umbilicus. It 
has four whirls, and measures long. "036, long. spir. '016, 
lat. -028, div. 50". 

^aZ».— Mazatlan ; 1 sp, off Chama ; L'pool Col. 

Family JEFFKEYSIADyE. 

Genus JEFFEEYSIA, Alder. 

Forbes Sf Hani. Br. Moll. vol. iii. p. 151, 1850 :—An. Sf Mag. 

Nat. Hist. 1851, vol. vii. pp. 193, m).— Woodto. Man. i. 137.— 

Phil. Ha?idb. Conch, p. 172. 
llissoella, Cri^ai/ (sine diagn.) Proc. Zool. Soc. 1847, p. 159, 

no. 286 -.—Fig. Moll. An. 1850, p. 86.— Phil. Handb. Conch. 

p. 195.— J2". ^ A. Ad. Gen. vol. i. p. 325. 
Oct. 1856. hk 



362 MAZATLAN UNIVALVES 

419. Jeffeeysia* bifasciata, n. s. 

J. t. suhel,evata, diaphanci, tenuissimd, Icevi, anfr. v. suhtwmi- 
dis, sutura imj)ressu ; lined spirali subsuturali ; anfr. prima 
minutissime gramilato ; pallide fused, fa^ciis spiralihus duabus 
fuseis ornatd ; aperturd subovali, peritremati eontimio, umbilico 
minimo ; opereulo rifescente, haud tenuissimo. 
Variat t.plus minusve elongatd ; eolore quoque pallida s»u corneo. 

Of this species, beautifully lustrous when viewed under the 
microscope with a good light, about 90 specimens were obtained, 
probably from the Algfc on the Uvanillgc. They are most likely 
of somewhat sedentary habits, as even in a living state they 
are not unfrequently incrusted with Coralline. The dried 
animals have a rich brown colour. Several retained their 
opercula, which are perfectly normal, and of a reddish brown. 
Long. '055, long. spir. '032, lat. '03, div. 30**. 
Hab. — Mazatlan ; rare, on ? Algse ; I! pool Col. 

Tablet 1716 contains 3 sp. richly coloured, of which 2 retain 
their opercula. — 1717, 3 sp. pale non-banded variety, one with 
beautiful incrustation of Coralline. 

420. PJeffketsia Aldeei, n. s. 

J. t. "J. hifaseiaice" simili, sed solidiore, multo majore ; anfr. 
V. magis planatisyfasciis angustis. 

Thi'ee dead specimens were found on Chama? which appear 
to be a distinct spiicies. Of the very numerous specimens of 
J. bifasciata, none approached it in size, though the number 
of whirls is the same. The station appears to be different, 
and the whirls flatter. It is dedicated to one who stands 
unsurpassed for accuracy and coiu-tosy among British Malaco- 
logists, and to wliom we owe the first full description of this 
very interesting genus. Lorig. "068, long. spir. '035, lat. *044, 
div. 35". 
Hab. — Mazatlan ; extremely rare, on Chama ; L'pool Col. 

Tablet 1718 contains the least incrusted specimen. 

• As a name, Rissoella has prpcedence ; but as the first accurate account of the 
genus was given by Aider, il seems fair to iidont his designation; especially a» 
Kissoid names are siifliciontlT plentiful, and the other is at the same time dis- 
tinctive, and preserves the reinemlirauce of one of the most accurate laboorers 
in British Mahicolopy. I'hilippi has settled the difficulty by adoptine both 
names as separate neuera, of which he places Jeffreysia in Foluainidae and 
Kissoella in Eulimidx. 



MAZATLAII UNIVALVES 363 

421. Jeffkeysia tumexs, n. s. 

J. t. tumente, dictphana, Icevi, tenuissimd, alhida ; vertice 
depressd ; anfr. iv. convexis, marginihus spirce exeurvatis; 
aperturd suhovali ; umbilico magna, carinalo ; operculo tenuis- 
simo, translucido. 

Differs from tlie least elevated form of J. bifasciata in its 
very swelling and somewliat irregular wkirls, transparent 
white texture, and large angulated umbilicus. The operculum, 
which was found in five out of the thirteen specimens, is per- 
fectly transparent, appearing black from the remains of the 
animal, which seems to liave been differently coloured from 
that of J. bifasciata. Long. '048, long. sjnr. -026, lat. -038, 
div. 55". 

Hab. — Mazatlan ; very rare, off Chama and Spondylus ; 
L'pool Col. 

Tablet 1719 contains 2 sp. ; one young and glossy, with the 
opercidum so situated as to shew the medial process ; the 
other adult. 



422. ? Jeffbeysia , sp. ind. 

Tablet 1720 contains a horny, transparent shell of three 
whirls, exactly like a small AmpuUaria. It may possibly be a 
nucleus, but is much more normally shaped than the many 
such that I have examined from this collection. Another im- 
perfect specimen was found with an additional half whirl. 
Long. -046, long. spir. -009, lat. "044, div. 130". 
Hab. — Mazatlan ; 2 sp. on Chama ; L'pool Col. 



Family TEUNCATELLID^. 

These shells are ranked with Cyclostomid;r by Phil, and 
C. B. Ad. ; with Littorinidir by Woodward ; doubtfully with 
Pyramidellidgc hy Forbes ; between Dentalium and P.n'arai- 
della by Grray, 1817 ; between Ctecum and Pyramidclla, do. 
1850 ; between Lacuna and Planaxis, do. 185.5. For an account 
of the animal of the Tr. Montagui, v. Clark Moll. Test. Mar. 
Br. p. 380, according to whom it is an undoubted Littorinid. 



3&4 MAZATLAN UNIVALVES 

Genus TETJNCATELLA, Risso. 

423. PTbuncatella , sp. ind. 

Tablet 1721 contains an extremely young shell and an older 
fragment, which may belong to this genus. The young shell 
looks like an Aclis ; but the vertex, as in Tr. Montagui is not 
sinistral, but mammillated, with the first whirl sunken and 
scarcely oblique. Tt has three and a half normal and very 
tumid whirls, scarcely diverging ; and is very much smaller 
than the corresponding state of Tr. Montagui, only measuring 
long. 'OlS, lat. '015. The fragment is "027 across-, with a con- 
tinuous peritreme, large umbilicus and smooth exterior. 
Hab. — Mazatlan ; off Spondylus, extremely rare ; L'pool Col. 

Family PLANAXID^. 
Genus PLAjS^AXIS, Lam. 

'i24. Planasis nigeitella, Forbes. 

Fi'oc. Zool. Soc. Dec. 1850, p. 273, pi. 11, f. 6. 

= Planaxis acutus, like, in Zeit.f.Mal. Nov. 1850, p. 169, 

no. 23. 
+ Planaxis obsoletus. Mice. loc. cit. p. 170, no. 24. 

.Although Menke's names have a month's priority, yet as the 
description of Forbes is much more accurate, and represents 
the whole species, while Menke only indicates the extreme 
forms, it is here preserved. It is given on the authority of the 
Kellettian collections as from Sau Juan Del Fuaco : but as it 
is an extremely abimdant shell, and yet was not found, either 
there or along the Californian coast, either by Mr. Nuttall or 
the Transatlantic collectors, it is probable that the specimens 
were collected at San Juan in the Gulf of California, or even 
at Mazatlan. That they are identical with the Mazatlan species 
is proved on comparison by the remarkable epidermis, which 
lies in an irregular mass, grooved in a comb-like manner 
diagonally ; and when this is removed, there appears a fine 
velvety coat lying in the interstices. This peculiarity', by 
which it may easily be separated from the very similar P. semi- 
sxdcata of the W. Indies, is found in both of Menke's forms, 
which pass into each other by insensible gradations. The 
nucleus has three tuberose whirls, Avith a flattened apex, very 



MAZATLAN tJNIVALTES 



365 



finely striated across ; the whirls then rapidly enlarge, and are 
at first smooth, then more or less spirally grooved. The mouth 
in the young shell is elongated, as in young Cerithia ; and in 
the very early stage, the general appearance is that of Litiopa, 
some species of which also have the first whirls abnormal. The 
shell varies in the greater or less elevation of spire, strength 
and frequency of spiral ridges, and in colour from brown to 
nearly black. The operculum is very thin ; slightly spiral, as 
in Nerita ; with the apex rather further ofl" from the extremity 
than is shewn in the figure in the P. Z. S. The tuberous 
nucleus is not seen in the adult, of which a normal specimen 
measures long. "48, long. spir. •22, lat. "33, div. 55". The 
youngest specimen is '05 long. 
Ba5.— "Straits of Juau del Fuaco," Forbes. [?]— Mazatlan ; in 

extreme profusion ; L'pool Col. 

Tablet 1722 contains a series of 262 specimens, obtained by 
repeated elimination from the examination of many thousands, 
aQd representing every observed variation of age and form ; 
also several loose oj)ercula. 

Ge.nus ALABA, H. Sf A. Ad. 

Testa ovoidea sen elongata ; Icevis, seu varie sculpta ; anfrae- 
tihics prirnis ahwrmalihus, tuherosis, vertice stibmamillato, vix 
declivi ; apertura ad basin effusd seu angulata ; columella, 
haud plicatd. 
Pars = Alaba, H. ^ A. Ad. Gen. vol. i. p. 241 : (diagn. auct.) 

The species here grouped together, from their general form 
and sculpture have relations with Odostomia, Chemnitzia and 
EulimeUa ; but are separated from them by the want of sinis- 
tral apex, which seems to be compounded-for by the abnormal 
character of the first three or four whirls. These are always 
different from the rest, either in sculpture, divergence or both ; 
and generally present the appearance of a tuberous root. In 
this respect they have relations with Stylifer, from which they 
difier in the straightness of the axis, the want of sinistral apex, 
and the strong sculptured habit of many of the species. In 
some respects they resemble Litiopa ; but diff'er in habit of 
growth, and in rhe want of Achatinoid truncation of the base. 
Not knowing any genus in which they could consistently 
remain, I had described them under the provisional name of 
Tuberia. But as the typical species is clearly congeneric with 



366 MAZATLAN UNIVALVES 

Alaba, (described in English by Messrs. Adams as a subgenus 
of Cerithiopsis,) there did not appear cause for adding another 
name for those species which do not accord with their diagnosis. 
The description of Tuberia is however retained, in order to 
include the whole group. Their true position, of course, can 
only be satisfactorily she^vn when the animals have been 
examined. 

425. Alaba stjpealieata, n. s. 

A. t. tenu\ conic&, albidd, posteaftisco irregulariter strigatd ; 
nitidd, subdiaphand , marginib'.-.t spirce variantihus ; vertice 
minimo, rotundato, parum decUvo ; dein avfr. iv. tuberosis, 
marginihus ijIus minusve paraUelis, suturis parvis, tenuissime 
iransvei'sim lindatis, lira spirali supramediand ; dein anfr. 
iv. subnormalibus, Icevibus, subplanatis, conicis, suturis hand 
impresses; peripherid vix rotundatd, aperturd subquadratd, 
ad basin suhangulatd ; dein anfr. iii. nortnalihus, tumidis, 
spiraliter ienue striatis, striis distantibus ; varicosis, varicibus 
quoque in anfractu tribus, attingentibus, tumidis, concavis ; 
aperturd subovali ; labro tenui, ad basin undato ; labio tenuis- 
simo, parvo ; columelld vix intortd. 

About 50 specimens were found of this remarkable shell ; 
but most of them so very imperfect, and so different in char- 
acter at different periods of growth, that only the late and 
fortunate discovery of a fresh adult specimen, led to their 
identification. In its usual adolescent state, it might rank as 
a Eulimclla, but for the want of the Chemnitzoid apex. It 
has one whirl, sufficiently' sloping to give the top of the striated 
portion a mammillated appearance. The first four whirls look 
like a thimble, and differ from the rest not only in sculpture, 
but in the margins which are nearly parallel ; Avhile afterwards 
the}' are more or less divergent, resembling in their irregularity 
some species of Stylifer. After liowever making foiu* whirls 
in an apparently normal condition, it changes again, and as- 
sumes a Bittioid aspect. The flattened whirls become tumid, 
their smooth surface spirally striated, the porcellanous white a 
rusty brown in irregular stripes, and the periphery' rendered 
irregular by timiid hollow varices, three in a whirl. The 
mouth which has always been angiUar at the base of the 
columella, now develops a very slight wave, scarcely amounting 
to a notch. As far as the specimens shew, this is the end of its 
changes. It most closely resembles a W. Indian species, 
Cingula tervaricosa, C. B. Ad., which however is larger, >vith 



MAZATLAN UNIVALVES 367 

the wliirls more regularly divergent, and not so tumid towards 
the end. This has the same kind of sculpture on the nticleoid 
whirls, but is wanting in the spiral line which :s characteristic 
of the Mazatlan shell. An adolescent sp. with three subnormal 
whirls, measures long. "OGT, long. spir. '04, lot. "035, div. 30". 
The largest „ '19, „ -125, „ '075, „ 22", 

ffab. — Mazatlan ; very rare, on Chama and Spondylus ; 
L'pool Col. 

Tablet 1723 contains a young sp., the most perfect adult, and 
a broken sp. with the nuclear portion distinct. 

426. Alaba violacea, n. s. 

A. t. solidiore, conicd, IcBvi ; anfr. primis IcBvibus, tumidis, 
violaceis, pavum divergentihus, hand jilanatis, suturis impressis, 
albidis ; peripherid vix angulatd, umhilico nullo ; superjieie 
transversim minutissime rugulosd. 

This shell has unfortunately lost its apical whirl, and the 
last ; but the characters are suiScientlj^ distinct. It differs from 
A. supralirata in the smoothness and tumidity of the tuberose 
whirls ; and in the extremely minute corrugation of the other- 
wise smooth surface, in which it agrees with A. mutans and 
PChrysallida clausiliformis. The specimen has three normal 
whirls ; and measures (allowing for the apex) long. '06, long, 
spir. -037, lat. "032, div. 35". 
Sab. — Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 

Tablet 1724 contains the specimen. 

427. Alaba teeebealis, n. s. 

A. t. solidd, conicd, apicem versus acutissime terebrante, albo- 
fuscd, Imvi ; anfr. primis parum rotundatis, maxime elongatis, 
angustissimis, marginibus pcene parallelis ; anfr. normalibus 
planatis, suturis haud monstrantibus, marginibus sj)irce dila- 
tantibus ; basi parum rotundatd, umhilico nullo. 

The only specimen found is in a similarly imperfect state 
with that of the last species ; from uhich it differs in the great 
elongation of the less swollen tuberous whirls, and in the 
Eulima-Uke aspect of the flattened normal whirls. Of these 
there are four; and the specimen measures long. "067, lo)ig. 
spir. -04.5, lat. "03, div. 40". 
Mab. — Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 

Tablet 1725 contains the specimen. 



368 MAZATLAN UNIVALVES 

438. Alaba alabastbites, n. s. 

A. t. solidissimd, alhd, turritd ; vertice anfr. uno et dimidit 
minimis, parum declivibiis, immersis ; dein anfr. iii. tuherosis, 
l(Bvihus, marginihus divergentihiis ; compactis, curtis, suhplana- 
tis ; dein anfr. normalihiis bubplanatis, parum compactis, lirit 
tolidis transversis circiter xvi. in lineas rertas a vertice basin 
versus continuis, suturis impressis ; liris ad. peripheriam evani- 
dis ; umbilico nullo ; marginibus spircB rectis, haud multum 
divergentibus. 

In this species, the sculpture of which is like a very strongly 
marked Chemnitzia, the tuberous whir-s are compact, thimble- 
shaped, and rather diverging, so that the last of these has a 
rather larger diameter than the first of the normal ones ; which 
then proceed at a rather less angle of divergence. The only 
specimen is broken below ; it has three normal whirls, and 
measures long. '055, long. spir. '035, lat. "027, div. 27". 
Sab. — Mazatlan ; 1 sp. ofi Spondylus ; ISpool Col, 

Tablet 1726 contains the specimen. 

429. Alaba scalata, n. s. 

A. t. ienuissimd, elongatd, Chemnitziformi, alhd ; vertice 
minimo, rotimdato, parum decUvi ; dein anfr. iii. tuherosis, 
hsvibus, subrotundatis ; dein anfr. normalibus elongatis, lirulis 
transversis aeutis (circiter xxr.) ornatd, circa basin subrotunda- 
tam vix continuis ; aperturd subquadratd, ad basin angulatd. 

This Chemnitzoid shell is not unlike Parthenia scalariformis ; 
but presents the tuberous whirls with the rounded top instead 
of the sinistral apex. It has only one normal whirl and a half, 
and measures long. '036, long. spir. '02, lat. '018, div, 20". 
Sah. — Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 

Tablet 1727 contains the specimen. 

430. PAlaba conica, n. s. 

?A. t. conicd, Troehoided, albidd ; anfr.' primis subtubcrosis, 
Icevibus ; dein valde divergentibus, anfr. normalibus 'vr.planatis, 
costis radiantibus circiter xvi., marginibus spirce rectis conveni- 
entibus, undulatis, ad peripheriam angulatam truncatis ; lirulis 
spiralibus supereunfibus, in spird circiter vi., ifi basi planatd 
circiter vi. rotundatis ; suturd cvcavatd ; aperturd subquadratd, 
ad basin angulatd ; lahio tenui, umbilicum parum monstrante. 



MAZATIAN UNIVALVES 369 

This sliell closely resembles Chrysallida nodosa in form and 
sculpture ; but although the specimens were broken, there is 
no indication of columellar fold ; what remains also of the apex 
accords better with Alaba than with that genus. The char- 
acter of the mouth comes nearest to A. supralirata. Long. *08, 
long. spir. '044, lat. 'OoG, div. 50". 
Hab. — Mazatlan ; 4 sp. off Spondylus ; L'pool Col. 

Tablet 1728 contains the most characteristic specimen, though 
another retains rather more of the apes. 

481. PAlaba mijtans, nam. prov. 

A. t. ovoided, alba ; vertice parvo, deelivi ; anfr. ii. sequenti- 
bus tumentibus, Icevibus ; dein anjractu uno minus tumente, 
superficie transversim minutissime rugulosd, interdum costis 
obsoletis transversis ; dein anj'ractibus normalihus ii., liris 
validis spiralibus cinctis, (in anfr. penult, x.j interstitiis rugulis 
minutissimis transversim orjiatis, costis quoque transversis, pmne 
obsoletis, aperturam versus evanidis ; basi rotundatd ; aperturd 
ovali, ad basin effusd ; rimuld umbilicali ornatd ; peritremati 
continuo ; labro a lirulis indentato, labio tenui ; columelld haud 
plicatd. 

The shell, in its disparity of whirls, and in the minute 
transverse rugulation of its surface resembles ? Chrysallida 
clausiliformis ; in its ovoid form, the more t3T)ical Chrysallidse ; 
from -which it differs in the entire absence of columellar plait, 
as an otherwise unfortunate breakage on the spire clearly 
proves. It may be a Eissoid. and resembles in many respects 
PLitiopa saxicola, C. B. Ad. Pan. Shells, p. 183, no. 256, (which 
Dr. Gould assigns to Ciugula, not having any columellar trun- 
cation, and on the labrum of which, in Mr. Cuming's specimens, 
there is no deposit, but a continuous peritreme, with an umbili- 
cal chink.) Long. "088, long. spir. '018, lat. '046, div. 33°. 
Sah. — Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 

Tablet 1729 contains the specimen. 

432. PAlaba laguncula, nom.2^rov. 

?A, t. elongatd, albo-fiiscd ; vertice tumentiore, deelivi ; anfr. 
iv. pin mis Icevibus, subplanatis, suturis canali parvd, impressd 
instructis, marginibus s2)ir(B valde excurvatis ; dein subito liris 
spiralibus validis, rotundatis, extantibus ; interstitiis parvis, 
decussatis ; 



370 MAZATLAN TJNIVALTES 

Tablet 1730 contains a fragment, intermediate in form be- 
tween PA. mutaus and PCkrysallida clausiliformis, remarkable 
for the sudden transition, after 4 whirls, from a perfectly 
smooth to a highly sculptured surface. The smooth part 
measures *045 by "023. 
Sah. — Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 

433. PPAlaba , sp. ind. (a.) 

Tablet 1731 contains a fragment of a somewhat large shell ; 
the first four whirls swelling and smooth, like PA. mutans ; 
then with four whirls sculptured as in Chrj^sallida, with stout 
radiating ribs decussated with spiral strise. P May it however 
have belonged to a Nassa. 
Sah. — Mazatlan ; extremely rare, off Spondylus ; L'pool Col. 

434. PAlaba sp. ind. (h.) 

Tablet 1732 contains a fragment of a strong shell, "rrith 
smooth, prominent, strong, elongated tuberous portion, (the 
first whirls broken) followed by divergent, somewhat rounded 
whirls, cancellated as in Phos. 
Sah. — Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 

Family OVULID^. 

Genus OVIJLA, Brug. 

Enc. Meth. vol. xv. no. ^7.— Phil. Sand. Conch, p. 162. 
Amphiceras, (Gronov.) Gray, Proc. Zool. Sac. 1847, p. 143 : — 

=Amphipcras. March. 
Volva (Boltcn) H. ^' A. Ad. Gen. vol. i. p. 272. 

435. OVULA VAEIABILIS, C. JB. Ad. 

Ovula variabilis, C. B. Ad. Pan. Shells, pp. 31, 304, no. 4. 

(May, 1852.) 
Ovula Californica, Sow. Proc. Zool. Soc. [teste Cuming : P tibi.] 

This shell closely resembles the Atlantic species, O. imiph- 
catum. Saw. (S. Carolina), O. aciculare. Lam. (W. Indies) and 
O. subrostratimi. Sow. (Honduras). The striae at each end are 
extremely fine, and are rarely traceable over the whole surface. 
The shape is sometimes stunted and broad, sometimes acimiin- 



MAZATLAN TJNITALVES 371 

ate. The colour varies from light buff to pink and dark violet 
purple, the latter prevailing. The posterior beak is broadly keel- 
ed outside. The largest sp. measures long. '63, lat. '23, alt. "15. 
A short sp. „ '43, „ "17, „ '12. 

A young, acumiaate sp. „ "38, ,, "11, „ '07. 

Kah. — Panama ; rare, on Gorgonia (the various colours of 
which are imitated by the shell,) at low water mark of 
spring tides ; C. B. Adams. — Mazatlan ; rare ; L'pool. Col. — 
San Juan, L. Cal., Lieut. Green. — Sta Barbara, Col. Jeioett. 
Tablet 1733 contains 8 sp.. displaying the principal difierences, 
kindly presented by J. Hibbert, Esq. of Liverpool. 



Family CYPR^ID^. 

Gentts CYPE^A, Linn. 

Cypraea, Linn. pars. Shell comparativelj'' thin, cyUndrical, 
faintly callous at the sides. 

436. Ctpe^a exanthema, Linn. 

Syst. Nat. ed. 12, p. llT2.— Wood. Ind. Test. pi. 16, f. l.—Dillw. 
Descr. Cat. vol. i. p. 436, no. l.— Gray, Monogr. Cypr. Zool. 
Journ. vol. i. p. 139 -.—Bescr. Cat. p. 2, no. 7. — Soio. Conch. 
Ml. f. ViQ.—Kien. Leon. Conch, p. 71, no. 62, pi, 4, 5, (f. 1.) 
9,10, (f 1.) 21, (f. l.)-i2i'e. Conch. Lc. p]. 5, sp. 16.— X«?w. 
An. s. Vert. vol. x. p. 489, no. 2. — (For other references, 
V. Desh. in loco.) 

Jun. = Cypr8ea zebra. Linn. p. 3100, no. 8. et auct. antiq. 

+ Cypraea cervinetta, Kien. Leon. Conch, p. 74, pi. 6, f. 1, 2.— 
Desh. in Lam. An. s. Vert. vol. x. p. 547, no. 71. — =C. exan- 
thema, Rinds, Voy. Sulph. Moll. p. 6, (teste C. B. Ad.)— 
= C. exanthema, var. a & h. Gray, Zool. Journ. vol. i. p. 139. — 
= C. cervus, var. Rve. Conch. Lc. (teste C. B. Ad.) 

Comp. Cypra;a cervus, Linn. Mant. p. 548. — Rve. Conch. Lc. 
pi. 2, sp. 6. — = C.>T?r8ea cervina. Lam. loc. cit. no. 1. — Gray, 
p. 140.— &?{'. f. lib.— Kien. pi. 2, Z.—Rve. Conch. Syst. vol. ii. 
p. 263, pi. 287, 288, f 175. 
The form C. cervinetta was distinguished by Kiener, who 

regarded it as from the W. Indies and Senegal ; and was 

allowed with hesitation by Deshaj'cs, who says that it is per- 
h aps only an intermediate variety between the C. exanthema 



372 MAZATLAN UNIVALVES 

and C. cervus of Linn. The species was adopted for geo^aphi. 
cal reasons by Prof. Adams, who regarded all the W. Indian 
sheUs as C. exanthema, all those from the W. coast as C. cer- 
vinetta, and all those from the Polynesian islands as C. cervns 
( = cervina). While however the S. W. Mexican shells belong 
clearly and exclusively to the type C. cervinetta, those from 
Mazatlan belong with almost equal exclusiveness to the typical 
C. exanthema. An examination of several hundred specimens 
shews that the characters usually relied on to separate tbe 
species, are by no means constant. The Mazatlan shells rarely 
develop inner dots; but the number of spots i^ extremely 
variable, one specimen exhibiting on the abral half the numer. 
ous small spots of C. cervus, on the labial half the dis ant oce - 
lated spots of C. exanthema. The anterior dilation of the mouth 
is also variable, generally taking the open form of U cer- 
vinetta, but sometimes the narrower shape of C. exantliema. 
The columellar indentation and markmgs are a so variable. 
Sometimes the posterior labral deposit equals the labial, sonie- 
times decidedly exceeds it, sometimes Mis still more below t 
The size is very rarely small as m C. cervmetta ; f^J^aUy 
elongated as in C. exanthema, occasional y large and swollen 
as in C. cervus. The colour is either light or dark ; with the 
bands varying in distribution, and the mantle hue generaUy 
Sht, s'^.metimes waved. A swollen adolescent specimeu 
measures Zon^. 3- 44. Za#. 2 04. 

A cylindrical sp. » ^ ^' >' ^ ""* 

Wah — W. Indies, passim. — Barbadoes, fossil. Dr. Cutting.— 
(C. cervinetta,) Panama and Taboga •, 115 sp. at and just 
above low water mark of spring tides, under stones 15-JD m^ 
Tdfameter; C. B. Adams. -S. W. Mexico, common,* 
p p. a— Mazatlan ; not uncommon ; X pool tot. 
Tablet 1734 contains 3 sp. adolescent, banded.-l735, 1 do. 
form cervus.-1736, 3 sp. spots beginning.-1737 3 sp. adult, 
bands evident.-1738, 3 do. bands concealed.-1739, 3 sp. ad^ , 
light colour, spots very faint.-174«, 1 do. spots decided. -1741. 
1 80 slightly spotted, not banded, resembhng C. talpa.-1744. 
1 so right with few ocellated spots, left with close numerous 
simple ones— 17<13. 2 sp. with occUated spots ; one small, type 

. Before I was aware of the separation of C. eianthema and cervinetta, I on- 



1 



MAZATLAN UNIVALVES 373 

cervinetta, spots small, numerous ; the other riekly coloured, 
approaching C. Scottii, with exanthemoid aperture, deeply 
scooped columella, large spots, labial teeth prominent to the 
nail. — 1744, 3 sp. shewing variations in character of aperture, 
narrow to broad. — 1745, 3 sp. shewing variations in posterior 
callosities, spire prominent or concealed. — 1746, 1 sp. repaired 
after fracture. — 1747, 1 sp. glossy outside, but with the blue 
interior most beautifully spangled with Spirorbis, Vermiha & 
Defrancia iutricata. 

Subgenus LDTONIA, Gray. 

Zool. Journ. 1832, vol. i. p. 1 —Proc. Zool. Soc. 1847, p. 143.— 
-ff. i^' A. Ad. Gen. vol. i. p. 266. This group includes the 
Pyriform Cyprsese, (C. tigris, &c.) 

437. LUPONIA PspuRCA, Linn. 

Cypraea spurca, Syst. Nat. ed. 12, p, 1179.— Gray, Mon. Cypr. 
Zool. Journ. vol. i. p. 501, no. 11.— Sow. Conch. III. sp. 51, 
f. 53, 81, l()i.—Kien. Icon. Conch, p. 30, f. l.—Rve. Conch. 
Ic. pi. 14, sp. 68. 

= C. flaveola, Lam. An. s. Vert. vol. x. p. 525, no. 42, (non Linn.) 
= C. acicularis, Gmel. p. 3421, no. 107. 

This little shell may be a dwarf specimen of the Atlantic 
species (as the authorities have decided ; in which case it is 
difficult to say how it got into the box of C. arabicula ;) or it 
may be an allied Pacific form. It has rounded pits along the 
labral side, and a ievf at the top and bottom of the labial. One 
turn of the spire is seen. Colour resembling C. stercoraria on 
the back ; orange brown at the sides ; light brownish yellow 
in front. Long. '84, lat. '5, alt. "39. 

Hah.— {C. spurca) Mediterranean, auct.— Canaries, M' Andrew^ 
— PMazatlan ; 1 small sp. ; L'pool Col. 
Tablet 1748 contains the specimen. 

Subgenus AEICIA, Gray. 

E. Sf A. Ad. Gen. vol. i. p. 265.— Shell greatly thickened at 
the sides, base flattened, back gibbous. 

438. Aeicia aeabicula, Lam. 

Cypraea arabicula, Lam. in Ann. Mits. vol. xvi. no. 54, p. 100 : — 
An. s. Vert. vol. x. p. 531, no. 5i.— Gray, Zool. Journ. vol i. 
Oct. 1856. 



374 MAZATLAN UNIVALVES 

p. 78 :— Z>eser. Cat. p. 3. no. 13.— TFboc?, Ind. Test. Swppl. 

pi. 3, f. 7.— VaI. in. Sumb. Eec. Obs. vol. ii. p. 3M.—Sow. 

Conch. HI. pi. 101, f. 77.— Kien. Icon. Conch, p. 125, pi. 28, 

f. B.—Rve. Conch. Icon. pi. 13, f. GO.—Mke. in Zeit. f. Mai. 

1851, p. 33, no. 112.— C. B. Ad. Pan. Shelh, p. 32, no. 6. 
Aricia arabicula, H. ^ A. Ad. Gen. i. 266. 
? + Cypr£ea punctulata, Gray, Zool. Journ. vol. i. p. 387. — Sow. 

Conch. III. pi. 4, f. 20.— Kien. Conch. Icon. p. 114, pi. 21, 

f. 2. — Desh. in Lam. An. s. Vert. vol. x. p. 563, no. 92. — 

(Panama, with C. arabicula, C B. Adams.) 

This shell differs essentially from A. Arabica in the concealed 
spire, white teeth, and shape of the mouth and front, which 
have a general resemblance to A. caput-serpentis. The varia- 
tion in tint and markings is considerable ; some few diseased 
specimens even presenting the aspect of A. obvelata. Avery 
large number were found, repaired after more or less severe frac- 
tures. The largest specimen measures long. 1' 45, lat.l'. 

An elongated sp. ,, „ 1'17, „ '9. 

A transverse sp. „ „ 1'19, „ '75. 

The smallest adult „ '84, „ '54. 

^rtJ.— Acapulco, Humboldt c^ Bonpland.St. Elena and Real 
Llejos, under stones, Cuming. — Panama ; 7 sp. under stonefl 
from 8 — 20 in. in diameter, at and just below low water mark 
of neap tides ; C. B. Adams. — S. W. Mexico, common ; 
P. P. C. — Mazatlan ; in extreme profusion ; L'pool Sf 
Havre Col. 

Tablet 1749 contains 4 sp. young and adolescent. — 1750, 5 sp. 
dark, pattern indistinct. — 1751, 5 do. distinct. — 1752, 5 sp. 
smaU size, dark. — 1753, 5 sp. lighter, verv* small. — 1754, 5 sp. 
normal state. — 1755, 5 sp. light, pattern distinct. — 1756, 5 do. 
indistinct.— 1757, 4 do. very light.*— 1758, 3 do. with opaque 
whitish deposit. — 1759, 1 sp. uniform greenish yellow, without 
spots. — 1760, 5 sp. greenish, light markings. — 1761, 5 do. dark, 
pattern distinct. 

Specimen.<t shewing side.';. 1762, 5 sp. sides orange, panther 
pattern.— 1763, 2 sp. with numerous spots and dots. — 1764, 
3 sp. spots large, few. — 1765, 1 sp. spots small, numerous. — 

• One of these appears to lirlong to the form C. panctulsta : but the g^radations 
between it and the typical C. araliicula are so numerous and gradual that I am 
unable to separate tliem. Mr. Uaskoin however, whose authority in this genus 
is paramount, regirds iho species as distinct. 



MAZATLAN UNIVALVES 375 

J766, 3 sp. spots shaded— 1767, 3 sp. spots few.— 1768, 5 sp. 
very callous. 

Tablet 1769 contains 2 sp. witli broad straight mantle mark.— 
1770, 5 sp. mantle mark irregularly waved.— 1771, 3 sp. shew- 
ing changes in mouth. 

Abnormal specimens. Tablet 1772 contains 5 sp. after sbght 
fractures.— 1773, 5 sp. somewhat deformed by fracture.— 1774, 
2 sp. twisted.— 1775, 4 sp. after serious injury to labrum.— 1776, 
4 do. labium.— 1777, 1 sp. which has bridged over the aperture 
•22 in length, leaving a hole at the posterior canal.— 1778, 3 sp. 
mantle irre^arly injured.— 1779, 4 sp. with large scar on the 
shoulder (not uncommon), — 1780, 3 sp. with anterior scar, 
shewing violet layer.— These 120 specimens represent all the 
variations observed among many thousands. 



Genus TEIVIA, Gray. 

Zool. Journ. 1832, vol. i. p. 1 -.—Proe. Zool. Soc. 1847, p. 142. 

SheU small, front lu-ate, back with ribs or tubercles. 
Cyprsea, pars, auct. 

439. Tbivta pusttjlata, Lam. 

Cyprsea pustulata, Lam-. Ann. 3Ius. vol. xvi. p. 101, no. 56 : — 
An. s. Vert. vol. x. p. 5.35, no. 56.—Dllltv. Descr. Cat. p. 469, 
no. 6Q.— TFood Lul. Test. pi. 17, f. 63.— &20. Gen. f. 5 :— 
Co7ich. III. pi. 102, f. 71.— Gray Zool. Journ. vol. i. p. 513.— 
Kien. Icon. Conch, p. 128, pi. 2, f. ^.—Rve. Conch. Icon. 
pi. 15, f. 7Q.— Chenu Lee. Elem. pi. 2, f. 11, Y^.—MTce. in 
Zeit. f. Mai. 1851, p. 33, no. 113.— C. B. Ad. Pan. Shells. 
no. 9, p. 35. 
Trivia pustulata, Gray Descr. Cat. p. 16, no. 138.— Pe«. Cycl. 

vol. viil p. 257. 
Pustularia pustulata, M. Sf A. Ad. Gen. i. 269. 

This extremely beautiful species when young has much the 
form of Simnia (Ovula) patula, with the spire entirely con- 
cealed, and the surface most delicately cancellated as in Ficula. 
On turning-in its labrum, it first develops white facial ribs on 
a dark ground, afterwards the pustules on the back, finally 
those terminating the ribs. There often appears a white layer 
at the sides, in which case the lateral tubercles have generally 
a yellow tint ; and always two ill-defined brown dashes, near 



376 MAZATLAN UNITALVES 

the top and bottom of the back. The pustules are almost 
alwaj's of a rich reddish orange, with a ring of dark at the 
base. The dorsal line is scarcely indented, but is free from 
pustides. The front ribs are often continued fauitly over the 
sides. Shape oval or produced, with beaks more or less 
prominent. Labral teeth about 18 ; sometimes these are 
formed by principal ribs ; sometimes by fainter intercalary 
ones, as in T. Solandri ; sometimes there are marginal inter- 
calations. Pustules very variable in number ; two dwarf 
specimens have 94 and 176 respectively. Columellar excava- 
tion long and deep, bounded externally by a sharp rib. The 
smallest adult specimen measures lo)ig. 'ol, hit. '3, alt. "21. 

The largest do. „ '94, ,, '6, „ "4. 

A broad sp. „ -78, „ '56, „ -36. 

An elongated sp. „ '76, „ "4, „ "34. 

JIab.~ Mexico, Humboldt Sf Bonpland. — Panama and Isl. 

Plata, [near Cape San Lorenzo, lat. 1'6"] under large 

stones, at extreme low water mark of spring tides only, rare ; 

C. B. Adams.— S. W. Mexico, P. P. C— Mazatlan ; L'pool 

Col. 

Tablet 1781 contains 7 sp. in different stages of growth. — 
1782. 7 sp. white conspicuous. — 1783, 7 sp. pustules few, large. — 
1784, 7 sp. usual state. — 1785, 7 sp. pustules small, crowded. — 
1786, 3 sp. broad form.— 1787, 3 do. elongated form.— 1788, 
2 sp. ashy tint, pustules scarcely bordered. — 1789, 2 sp. shew- 
ing extremes of size. — 1790, 2 dwarf sp. shewing extremes of 
shape and markings. 

440. Tbitia kadians, Lam. 

Cypra?a radians, Lam. Ann. Mus. vol. xvi. p. 102, no. 62 : — 

All. .f. Vert. vol. x. p. 540, no. 62.— Grat/ Zool. Jouni. vol. iii. 

p. 364.— FrtZ. in Hnmb. Pec. Obs. vol. ii. p. 335.— Po^ ^ 

Mich. Moll. Mus. Bouai, vol. i. p. '\So.—Sow. Conch. Lll. 

pi. 119, f. I'Ho.—Rve. Conch. Si/st. pi. 286, f. 11^ -.-Conch. Ic. 

pi. , f. Il7.-Kien. Icon. Conch, p. 129, pi. 23, f. 3.— C. B. 

Ad. Pan. Shells, p. 37, no. 10. 
Cy-prEea oniscus, IFood Ind. Test. pi. 17, f. 58, (err. l>-p-)— ^"^on 

C. oniscus, Lam. An. s. Vert. vol. x. p. 540. no. 63 -.—Dillw. 

Descr. Cat. p. 466, no. 61 :— v. Bc&h. in loc. 
Trivia radians, Cra;/ Descr. Cat. p. 16, no. 137. 

Most of the Mazatlan specimens were dead ; but when fresh, 
it is of a brownish colour, with some of the lines interrupted 



MAZATLAN UNIVALVES 377 

on the front surface.* Labral teeth 13—17, none^intercalary. 
Shape variable, ovoid or oval ; generally with thick callosity 
on each side, and flattened face. The largest normal speci- 
men measures long. '81, lat. "64, alt. "43. 

A rounded sp. „ "73, „ '6, „ '47. 

An elongated sp. „ '81, „ "55, „ '38. 

Sab. — Acapulco, Humholdf. Sf Bonpland. — St. Elena, under 

atones, Cuming. — Panama, extremely rare, C. B. Adams. — 

Mazatlan ; very rare living ; L'pool Col. 

Tablet 1791 contains 2 sp. adolescent, ribs forming ; 1 adult, 
very fresh ; 1 do. teeth close as in T. Solandri ; and 1 sp. 
broken in two, shewing inner lips. — 1792, the 3 sp. above 
measured. — 1793, 3 sp. dwarf form, resembling T. Solandri. 

441. Teivia Solandri, Gray. 

Cypra^a Solandri, Sow. Conch. III. no. 128, f. 43. — Rve. Conch. 
Ic. pi. 21, sp. 113.— J/I-e. in Zeit.f. 3fal 1817, p. 183, no. 30. 
Trivia Solandi-i, H. Sf A. Ad. Gen. i. 269. 

Distinguished normally from T. radians by smaller size, 
redder colour, less swollen sides, rounder face with unbroken 
lines, greater excavation of the columella, and the presence of 
2 — 4 intercalary teeth in the labrum.t the whole number 
varying from 15 — 18. An examination of at least 150 specimens 
of this species and T. radians has not confirmed the impression 
of distinctness which is given by extreme forms. The last is 
the only reliable character, and even that is varying ; so that 
some specimens of T. radians have more teeth than others of 
T. Solandri. The arrangement of ribs in each form is too 
uncertain to found specific marks upon them. An examination 
of the animals, or at least of several hundred fresh specimens 
from difiTerent localities, appears needful to decide the point. 
The largest of the specimens, with only two intercalary teeth, 
measures long. '63, lat. "44. alt. '35. 

A rounded sp. „ -54, ,. "39, „ '29. 

An elongated sp. ,, '65, „ 'SG, „ -28. 

Hah. — Mazatlan ; very rare ; L'pool Col. 

Tablet 1794 contains 2 sp. approaching the dwarf form of 
T. radians. — 1795, 3 sp. normal state. 

• Desk, erroneously states that each of the rays ends in a tabercle. 

t Reeve states that there is "an intermediate tooth between each of those 
terminating the ribs." In the Mazatlan specimens, I have never seen more than 
4, generally 2 or 3 ; these moreover are not teeth, but rudimentary ribs, con- 
tinued for some little distance over the base. 



378 MAZATLAN UNIVALVES 

442. Tbivia SAN guinea. Gray. 

Descr. Cat. p. 14, no. 119.—^. Sf A. Ad. Gen. i. 269. 

Cyprsea sanguinea, Soio. Cat. Cypr. p. 12, no. 115 : — Conch. HI. 

pi. 6, no. 32. — Lam. An. s. Vert. vol. x. p. 570, 102.— iBre. 

Conch. Ic. pi. 23, f. m.— Chen. Lee. Mem. pi. 10, f. 9, 10.— 

Mke. in Zeit. f. Mai. 1847, p. 183, no. 29:— 1851, p. 34, 

no. 114.— C. B. Ad. Pan. Shells, p. 38, no. 12. 
+ Cyprsea fusca. Gray in Soiv. Conch. Lll. no. 120, f. 37. — Rve. 

Ccmch. Lc. pi. 24. sp. \2,\.—Mle. in Ze'it.f. Mai. 1851, p. 34. 

no. 115. (Galapagos & Bay of Guayaquil, Cuming.) 
Comp. Cj'prsea rubescens,* Gray, Proc. Zool. Sac. 1832, 

p. 185.— i?re. Conch. Lc. pi. 25, sp. 141.— C. B. Ad. Pan. 

Shells, p. 38, no. 11. (Galapagos, Cuming. — Panama, C. B. 

Adams.) 

After very careful and repeated examinations of many 
hundred specimens, I feel unable to separate tlie C. fusca from 
the C. sanguinea. The colour varies from very dark brownish 
purple, with blood-red stain on the back, to a brown with 
scarcely any admixture of purple or red ; and again to a general 
reddish pink, like C. rubescens. The differences of shape, 
from aiounded form approaching T. subrostrata to an elonga- 
tion approaching T. suffusa, do not accompany the differ- 
ences of colour, but are found in each state. The swelling at 
the basal margins is very variable. The sculpture is by no 
means constant, the ribs (of uncertain number) being continu- 
ous over the back, or variously interrupted ; intercalations and 
confluences frequently appearing. The columella is broadly 
indented over the whole length, with a wave in the middle. 
The smallest sp. measures long. "27, lat. *21, alt. '17. 

Tbe largest sp. „ „ '53, „ '41, „ '31. 

An elongated sp. „ „ '47, „ '83, „ '27. 

A broad sp. „ ,, "36, ,, '28, ,, '23. 

Hah. — Panama and Mexico, Sowerby. — St. Elena, under 
stones, Cuming. — Panama, one dead sp. C. B. Adams. — 
Mazatlan ; abundant, (generally dead ;) L'pool Col. 
Tablet 1796 contains 5 sp. dark brownish purple, red stain 

developed.— 1797, 4 do. red scarcely appearing.— 1798, 5 sp. 

dark brown, red stam slight.— 1799, 4 do. red evanescent,— 

• The specimens of T. fusca and T. rubescens in Mus. Cuming seem to be 
extreme varieties of T. sanguinea. Those in Mua. Ciaskoin however appear dis- 
tinct, especially of the form rubescens. 



MAZITIAN TTNIVALTES 379 

1800, 3 do. light brown, without red.— 1801, 5 sp. light brown- 
ish purple, with red stain.— 1802. 4 do. diffused purple red. — 
1803, 5 sp. diffused red.— 1804, 4 sp. reddish pink.— 1805, 4 sp. 
shewing changes of size.— 1806, 5 sp. elongated form.- 1807, 
4 sp. broad. — 1808, 4 sp. shewing variations in sculpture. — 

1809, 2 sp. distorted, and one broken open, shewing inner lip.— 

1810, 2 dead sp. with ribs very distant, having the aspect of 
T. radians. They may belong to T. Californica. 

4A3. Tbivia pulla, Gaslc. 

Cyprsea pulla, GasJc. in Proe. Zool. Soc. 19M, p. 24 :— do. 1848, 
p. 97, no. 11. — (Non C. puUa, Gmel. = C. adusta, Chem.J 
One specimen was found of this pretty little species. It is 

more elongated than T. subrostrata, with projecting beaks ; 

the ribs interlocking alternately on the dorsal line ; colour 

brownish purple ; columellar indentation long and deep. 

Long. '25, lat. '\7^ alt. '14. 

Sdb. — Gralapagos Is. and Bay of Guayaquil ; Cuming. — 
Mazatlan ; 1 sp. with T. sanguinea ; L'pool Col. 
Tablet 1811 contains the sp. 

444. Teitia scbbosteata, Grai/. 

Zool. Journ. vol. iii. p. 363, (teste Sve.) 

Cypraea subrostrata. Sow. Conch. III. p. 13, sp, 119, f. 36. — 

Rve Conch. Ic. pi. 26, sp. 147.— J/It. in Zeit.f. Mai. 1851, 

p. 34, no. 116. 
Non Cypraea subrostrata, Desh. in An, s. Vert. vol. x. p. 581, 

no. 30, "fossile D'Orglande et de Nehou ; coquille lisse 

ct polie = Gray, Monogr. Cijpr. Zool. Journ. vol. i. p. 369, 

no. 30 : — Descr. Cat. Shells, p. 5, no. 36." 

There appears to be a W. Indian species, so closely allied to 
this, that the figiu-es quoted might apply to either. Dr. Gray 
however identified the solitary Mazatlan shell with the above 
name. The W. Indian shell (Bristol Mus.) is of a richer 
colour, with the beaks less rostrate, and the dorsal sinus 
deeper and broader. Long. "25, lat. "18, alt. 16. 

Hah. — Mazatlan ; 1 dead sp. ; Lpool Col. 

Tablet 1812 contains the specimen. 



360 HAZATLAK tTITIVAlVBS 

Family CAN CELL AEIAD^. 
Genus CANCELLAEIA, Lam. 

445. Cancellaeia tjeceolata, Sinds. 

Proc. Zool. Soc. 184:3, p. 47 ■—Voy. SulpL Moll.^j). 41, no. 171, 
pi. 12, f. 7, 8— Sow. T/ies. Conch, p. 443, no. 13, pi. 94, f, 48. 

Cancellaria obesa, P. P. C. Cat. Prov. ; non Sow. 

? = CanceUaria ovata, Mice, in Zeit.f. Mai. 1850, p. 181, no 51 ; 
non Sow. 

The character by which Mr. Hinds distinguishes this species, 
that the nail is not obstructed when drawn in the direction of 
the axis, is by no means constant. There was considerable 
variation in about 50 specimens examined. Shell sometimes 
with spire depressed, resembling C. obesa ; sometimes very 
prominent. Cancellations c ose and conspicuous on the early 
whirls, (the first 3 being smooth, deciduout,) afterwards very 
variable. Tvro sp. of nearly the same size have the ribs two to 
one. Spiral lines more or less expressed. The plaits have a 
slight callus below, near the termination of each, giving them in 
some positions a sub-bifid appearance. Sometimes there is a 
slight parietal tubercle. Labrum with 8-10 lirae inside. A young 
broad sp. measures long. '77, long. spir. '3, lat. "52, div. 70". 

An elevated sp. „ 1-24, „ "64, „ 7, „ 50". 

The largest sp. „ 1-37, „ '64, „ '85, „ 6O0. 
jgTaS,— West Coast America, between 12-3° and 21-5" N. Lat : 

viz. Gulf of Papagayo, 8-14 fm. ; San Bias, 7 fm. Hinds. — 

Mazatlan ; ver^^ rare ; L'pool Col. 

Tablet 1813 contains 4 sp. exhibiting extremes of variation. 

446. Cancellaeia goniostoma, Sow. 

Proc. Zool. Soc. 1832, p. 51 -.—Conch. III. no 47. pi. 13, f. 43 :— 
Thes. Conch, p. 427, no. 64. pi. 94, f 40.—MhII. Si/n. Noik 
Test. Viv. p. 73.~Mke. in Zeit.f. Mai. 1850, p. 181, no. 53.— 
C. B. Ad. Pan. Shells, p. 134, no. 157. 

Comp. Cancellaria costata, Gray, Sow. Tlies. Conch, sp. 60, 
p. 456, pi. 95, f 60, 61 ; pi. 96, f. 103 : + C. rigida, Sow. 
(Gambia.) 

Comp. C. brevis. Sow. Conch. III. f. 33 : — Kien. Icon. Conch. 
p. 14, no. 9, pi. 7. f. 2. (Patagonia, Kiener.) 



MAZATLAN UNIVALVES 381 

Kiener thinks that to C. brevis should be united C. rigida 
and C. goniostoma ; and certainly the species have a strong 
resemblance, as has also C. bicolor, Hinds. The Mazatlan 
shells, of which some hundreds have been examined, vary in 
the elevation of spire, in colour, sculpture, and in the angle of 
the aperture. Sometimes the labium is parallel to the axis, 
sometimes at an angle of nearly 30". Sometimes the ribs are 
sharp, distant, and scarcely nodulous ; sometimes running into 
each other, with strong tubercles. Sometimes the shell is near- 
ly white, sometimes of a rich purple brown, or brown orange. 
The first two whirls are smooth, followed by one which is 
finely cancellated, not shouldered. The umbilicus varies in 
size, and is more or less sculptiu'ed. The largest specimen 
measures Zowq'. 1"04, long, spir.'b'^, lat. '78. div.^°. 

A slender sp. „" 1-04, „ "6, „ -75, „ 70". 

A broad sp. „ "8, „ -37, ,. '64, „ 90«. 

iSr/^.— Conchagua, San Salvador; on sandy bottom, Sfm. ; 
Cuming. — Taboga ; 1 sp. C. B. Adams. — Mazatlan ; not 
uncommon ; L'pool Col. 

Tablet 1814 contains 3 young sp. — 1815, 3 sp. ordinary broad 
growth. — 1816, 2 sp. acuminated. — 1817, the largest sp. with 
the aperture only touching the penultimate whirl at the basal 
keel. — 1818, 3 sp. shewing variations in colour. — 1819, 2 sp. 
ribs distant. — 1820, 2 do. close. 



Family STEOMBID^. 
Genus STROMBUS, Linn. 

417. Strombus galeatus, Swains. 

Phil. Mag. Sf Journ. 1823, p. 401.— Gray Bescr. Cat. p. 2, 

no. 2.— Sow. Thes. Conch, p. 36, no. 54, pi. 10, f. \U.—Kim. 

Conch. Ic. p. 5, pi. 2 — Lam. An. s. Vert. vol. ix. p. 710, 

no. 33.— DmcZ. in Chen. III. Conch, pi. 26, 27, f. \.—Kusi. 

Conch. Cab.^. 13, no 5, pi. 4 a, f. 1, pi. 4i, f. 1, 2.— Eve. 

Conch. Ic. pi. 3, sp. 3, f, 3.— Jf^•e. in Zeit.f. Mai. 1851, p. 20, 

no. 92. 
Strombus galea. Wood, Ind. Test. Suppl 1828, p. 14.— pi. 4, 

f. 13, 14.- C. JB. Ad. Pan. Shells, p. Ill, no. 122. 
Strombus crenatus, Sow. Tank. Cat. 1825, App. p. xix. 



382 JIAZATLAN UNIVALVES 

This fine and graceful species appears to replace S. gigas on 
the W. coast of N. America, as S. Peruvianus does on the 
Pacific shores of S. America. When very young, the spire is 
fusiform, with spiral strife and transverse folds as in Fusidse 
(Colidse, Gray.) Cxradually the whirls lose their sculpture, 
and envelop each other, with a broad channel below the suture 
and an obtuse angle near the periphery. Beneath this are 
developed more or less faint obtuse spiral ribs, ending in slight 
crenations of the but-moderately expanded outer lip. Pos- 
terior channel narrow, ascending the spire. Epidermis de- 
ciduous, nearly smooth. Menke has described the operculum 
as like that of S. gigas, lancet-shaped, slantingly elliptical, 
with a keel-shaped line near the middle. It is figured in 
S. 8f A. Ad. Gen. i. pi. 27, f. la. lb. The entire stock of this 
beautiful shell in the L'pool Col. shared the fate of the Spondyli 
and large limpets. The specimens here displayed are from the 
Havre Col. Lony. 8"5, long. spir. 1'2, lat. 6'3, div. 90". 

Sai.— Grulf of Nieoya, on reefs at low water, Cuming =1?i\)0gaL 
(fragments) C. B. Adams. — S. W. Mexico, P. P. C. — 
Mazatlan ; not uncommon ; L'pool <^ Havre Coll. 

Tablet 1821 contains a young specimen, in perfect condition, 
6 '5 in length. — 1822, a fine adult specimen. 



448. Steombtjs granulatus, Swains. 

Bligh Cat. App. p. 8.— Wood Ind. Test. Suppl. pi. 4, f. 21.— 
Swains, in Haul. Exof. Conch, p. 36. — Sow. Thes. Conch. 
p. 33, no. 39, pi. 9, f. IQO.—Kien. Icon. Co?ich. p. 28, pi. 22, 
f. 1. — Lam. An. s. Vert. vol. ix. p. 713, no. 37. — Duel, in 
Chen. III. Conch, pi. 11, f. 5. Q>.—Kust. Con?h. Cah. p. 64, 
pi. 13, f. 13.— PtJP. Conch. Ic. pi. 14, f. 32.— C. B. Ad. Pan. 
Shells, p. 113, no. V2.k~Mke. in Zeit. f. Mai. 1851, p. 21, 
no. 93. 

This well-known species appears to abound in the warmer 
latitudes, but not to flourish at Mazatlan. It is easily recog- 
nized by its elevated spire, very stout nodules, and variegated 
painting. Epidermis rather rough, adherent. Long. 3" 44, 
long. spir. -96, lat. 1-61, div. 50". 

Hab. — St. Elena and Galapagos ; sandy mud, 6-8 fm. ; Cuming. 
—Panama, Col. Jewett.—T&boga, 7 dead sp. C. B. Adams.— 



MAZATLAN TTNITALVE8 383 

S. W. Mexico, common, P. P. C— La Paz, lAeut. Green.— 

Mazatlan ; extremely rare ; Lpool Col. 

Tablet 1823 contains a fine specimen, mended after repeated 
fractures, witli Vermetus and attachment of Crepidula onyx. 

Tablet 1824 contains a minute -n-hite transparent shell, (off 
Spondylus ; ) smooth below, angulated above, with linear aper- 
ture ; which may possibly prove to be the young of this species. 

449. Steombus gracilioe. Sow. 

Tank. Cat. no. 1792, p. xx. — TTooi, Ind. Test. Suppl. pi. 4, 
f. l.—Soiv. Thes. Condi, p. 32, no. 35, pi. 8, f. Ti.—Kien. Icon. 
Conch, p. 31, pi. 21, f. \.—Lam. An. s. Vert. vol. ix. p. 713, 
no. ZQ.—Bucl. in Chhi. III. Conch, pi. 17, f. 6, l.—Kust. 
Conch. Cab. p. 36. pi. 4 a. f. 6, 7.—Rve. Conch. Icon. pi. 16, 
f. Z^.—Mke. in Zeit. f. Mai. 1851, p. 22, no. 95.— C. B. Ad. 
Pan. Shells, 112, no. 123. 

Known from its Caribbsean analogue, S. pugilis, not only 
by its more slender outline, the faint development of the 
tubercles, obsolete on the last whirl, and the preponderance of 
yellow over red in the tint ; but by the epidermis, which is soft 
to the feel, very finely striated, adherent, and generally stained 
green by vegetable incrustations, A wholesale dealer in boxes 
of the W. Indian shell, states that this is a constant character 
of difference. Almost all the specimens had been repaired after 
more or less severe fractures. The shell varies in the amount 
of elevation of the spire. The first whirls have close radiating 
ribs instead of tubercles, crossed by spiral striffi. An adolescent 
sp. measures Zow/j'. 3"21., long. spir. 1'38, lat. 1'74>, div.QO". 
An adult sp.„ 3-17, „ 'SI, „ 2-05, „ 70". 

Hab. — St. Elena and Panama; sandy mud, 6— lOfm. ; Cum- 
ing.— Tahoga ; 1 dead sp. C. B. ^(/amA-.— Taheite, Jay. [?]— 
La Paz, Lieut. Green. — Mazatlan ; very rare ; L'pool Col. 
Tablet 1825 contains an adolescent, and an adult sp.— 1826, 
1 sp. mouth darkly stained.— 1827, 1 sp. labrum renewed after 
severe fracture. 



384 mazatlan ttnivalves 

Sttboedeb TOXIFEEA. 

Family TEEEBRID^. 

Genus TEEEBEA, Adanson. 

Terebra, Adans. pars. — Eyes at tlie outer bases of tlie tentacles. 

StTBGENTJS MYUEELLA, Hinds. 

S. ^ A. Ad. Gen. vol. i. p. 227. — "Wliirls with a tuberculated 
zone. 

450. MyUEELLA AIBOCINCTA, n. s. 

J£. t. conico-suhulata, acuminata, turritd ; fusco-purpureA 
seu olivaced ; anfr. planulatis, mperne cingtilo tuberculato, 
albo, interrupte fusco picto ; infra cvstis transversis, tuherculis 
hand semper convenientibus, liaud extantibits, obtusis ; lineis im- 
pressis spiralibus, plerumqiie iv. — vi., interdum cosiis decussan- 
tibus ; superficie totd spiraliter exillime striata, striis undulatis, 
irregularibus ; anfr. ultimo cingulo albido suturcB antecedente ; 
aperturd obovali, labro acuto, vix sinuafo, labia tentiissimo ; 
canali brevi, contortd, alte emarginatd ; carina acuta spiraliter 
ascendente, columellam vix plicante : operc. parvo, diaphano, 
aureo, rhombico, diagonaliter depresso, apice acuto, marginibus 
rectis, termino convexo. 
= Terebra armillata, Mke. in Zcit.f. Mai. 1^51, p. 34, no. 118, 

(non Hinds.) 
Comp. T. variegata, J/Xe. loc. cit. no. 117, (?uon G-raij.) 

Following US I thouglit the judgment of Dr. Menke, I have 
freely distributed this shell as T. variegata. According to the 
types however, that species is distinct ; it is not uncommon on 
the coast, but was entirely absent from the Mazatlan collection. 
The shell so named in Dr. Menke's mixed list may be the true 
T. variegata, imported, or one of the species now described. 
The present species is so closely related to T. armillata, Hinds, 
(teste types in Mus. Cum.) that there can scarcely be a doubt 
that it is the shell brought by Melchers. It even more closely 
resembles the Gambia species, T. intertincta. Hinds ; * from 

• ? Should not T. Africana, Chray, in Grif. Cuv. pi. 23, f. 5, be referred to this 
tpeciea rather than to T. variegata. The shell figured by Kien. Icon. Conch. 
p. 114, no. 10, pi. 2, f. 3, seems exactly to represent the T. variegata of the Gulf 
of California ; which differs from T. albocincta in being much larger, broader, 
not oUvaceoua, with sutural band broader and flatter in proportion, with the 
radiating costiB in the lower whirls nearly obsolete, and the oaso more rounded. 



MAZATLAN UNIVALTES 385 

which however it is distinguished by the absence of the lower 
row of tubercles. There are about 16 whirls, of which the 
first three are smooth, brown and translucent ; while the next 
three (about) display the costse without the spiral groove. The 
young shell is very dark coloured, with the ribs conspicuous ; 
the girdle gradually develops its white colour, and afterwards 
very irregular reddish brown spots. The cost^ gradually 
become fainter and more irregular, and are or are not decussated 
by the spiral lines. These are normally 4-6, but variable. 
The whole surface is covered with microscopic spiral striulse, 
irregularly waved, giving a rugose appearance. The sutural 
line is continued round the base in a faint white band. The 
deeply cut notch is bounded by a sharp keel externally, which 
runs round over the columella. The colour is almost always 
purplish brown, shadmg into olivaceous brown, more or less 
dark, lustrous. Operculum rhomboidal, more angular than in 
Pleurotoma, apex at the end of the long diagonal, expanding 
with straight sides and a scarcely rounded end. Most of the 
opercula found are abnormal, mended as from a subcentral 
nucleus. These beautiful shells are often encrusted with black 
mud, as in Drillia luctuosa, and have frequently been obliged 
to repair breakages at their extremity. The largest sp., unusu- 
ally slender, measures long. 1'6, long. spir. 1'2, lat. *34, div. 13". 
A young broad sp. „ 1-06, „ -74, „ '28, „ 19". 

Hab. — Mazatlan ; not common ; Upool Col. 

Tablet 1828 contains 5 sp. usual colour.— 18'29, 5 sp. richly 
olivaceous. — 1830, 3 sp. purplish brown predominating. — 1831, 
1 sp. ashy tint, markings faint. — 1832, 2 sp. markings very 
faint. — 1833, 3 do. markings vei-y strong.— 1834, 3 sp. repaired 
after simple and compound fractures. — 1835, 1 sp. with opercu- 
lum in situ ; and 2 separate opercula, one normal, the other 
mended after fracture. 



451. Myueeila Hindsii, ? n. s. 

M. t. " M. albocineta" simili, sed graciliori ; anfr. ccmfer- 
tiorihus ; omniyio albidd, rufo-fusco vix tinctd ; cinqulo aream 
majorem occupante, tuherculis validis ; costis evaiiidis ; lineis 
spiralibus iii.-v., striidis hand apparentibus ; plied columellari 
haud conspicud, 

A very few specimens were found of a whitish colour, faintly 
spotted with reddish brown ; with the ribs scarcely apparent, 
and the general surface smooth. Whether the form be of 
Nov. 1856. kk 



386 MAZATLAN TTKIVaLVES 

specific or only of sectional value (as will be learnt by induction 
from more numerous specimens,) it bears the honoured name 
of tlie author of the Synopsis of this genus in the Proc. Zool. 
5^00. 1843, pp. 159 et seq. Long.1'2^, long. spir. '98, lat. '27, 
div. 13". 

JSab. — Mazatlan ; 6 specimens, dead ; L'pool Col. 
Tablet 1836 contains 2 specimens, with extremes of sculpture. 

452. Mtueella stibnodosa, ? n. s. 

M. t. " M. albochictcB" forma et indole simili ; sed rufo-fiisca, 
alhido tinctd ; suhlcevi, lirulis radiantibus et striulis extantihus 
paucis spiralihus vix ornata ; superjicie hand striata ; peri- 
pherid subangulatd, subnodosd ; columella carina vix extante, 
hand plicatd. 

Two specimens were found, agreeing in shape exactly with 
T. albocincta, but with the faint spiral scidpture raised instead 
of indented, the surface destitute of microscopic striula?, the 
periphery subnodulous, and the keel surmounting the canal 
very faint. Long. 1"22, long. spir. 1' , lat. "36, div. 18". 
Sah. — Mazatlan ; extremely rare ; Uposl Col. 

Tablet 1837 contains the large specimen, with the spire bent 
through fracture. 



453. Myurella eufocinehea, ?n. s. 

M. t. "M. Hindsii" forma et indole simili ; sed omnitio rufo- 
cinered, haud maculatd ; cingulo latiore, pallidiore, margine im- 
presso, tubcrculos coifertiores angustos, magis elongatos gerente ; 
costis radiantibus aciitis expressis, tuberculis lineis vix undatis 
convciiientibus ; fascia circa j^eripheriam valde rotujidatam 
pallidiore; columelld a carina super canalem plicatd ; anfrac- 
tibus subconvexis, lineis spiralibiis, haud sculpturd mici'oscopicd, 
ornatis. 

In shape agreeing with M. Hindsii ; but with markings more 
hke those of M. albocincta, yet destitute of minute sculpture ; 
with the costs) much more developed, and the subliuear tuber- 
cles in a less waved line of junction. The cinctiu-e is marked 
off by a deep suture. This, and the more rapid roimding of 
the base, give the whirls a slightly convex appearance. One 
fresh, beautifully tinted specimen was found ; and a spiral 



MAZATLAN UNIVALVES 387 

portion whicli probably belongs to tbis species, tbough it ap- 
pears more slender. Long. 1"22, long. spir. '96, lot. '25, div. 13°. 
jSat.— Mazatlan ; extremely rare ; L'pool Col. 
Tablet 1838 contains the shell and the spiral fragment. 

Genus STJBULA, Schum. 

Subnla, Schum. Ess. 1817, pars.— Distinguished by having the 
eyes on the tips of the tentacles, instead of on their outer 
bases ; in the shell, by the absence of the spiral band, 
sLnuated lip and canal. 

Acus (Humph.) Gray, 1847, Proc. Zool. Soc. 1847, p. 139.— 
m S,- A. Ad. Gen. vol. i. p. 224.— Comp. Grai/, Gen. Moll. 1856. 

Terebra (pars) auct. 

154. SuBULA LUCTUOSA, Hinds. 

Terebra luctuosa, Proc. Zool. Soc. 1843, p. lol.— Hinds in Sow. 
Tlies. Conch, p. 181, no. 89, pi. 45, f. 121 .—MenTce in Zeii. 
f. 3Ial. 1851, p. 34, no. 119. 
Hastula (Acus) luctuosa, H. ^ A. Ad. Gen. i. 225. 

Shell nearly related to S. cinerea and S. strigilata from 
the E. Indies. Lustrous, with extremely fine, crowded spiral 
stria*, generally consisting of minute dots ; and very numerous, 
fine, slightly waved, sharp ribs on the tipper part of the whirls, 
evanescent in the middle. Between these are often extremely 
minute radiating striulse. About 6 of the first whirls are 
translucent and without ribs. Apex submamillary. First 
normal whirls with ribs strong. Outline very acimiinate and 
nearly rectilinear. The outer lip when perfect, wliich it rarely 
is, is gracefidly sinuated posteriorly in the direction of the 
ribs. About half the specimens are of an ashy or olivaceous 
brown ; the remainder of a lustrous brown black, often fading 
into light blue ; with scarcely any intermediate shades. Highly 
coloured specimens are sometimes found of a veiy dark olive 
green, with a row of infrasutural spots of purplish brown, 
sometimes over a yellowish green ground, occasionally con- 
fluent. The operculum is small, thin, horny, ovate, with faint 
waves of growth : its apex is terminal. The lai-gest of the speci- 
mens, (making allowance for the tip which is broken off,) 
measures lonq. 1"84, long. spir. 1'4, lat. '33, div. 12°. 

A broad sp. „" 1-02, „ 1-18, „ -34, „ 14°. 

An attenuated sp. „ 1-37, „ 1'03, „ '26, „ 11°. 



388 MAZATtAN TJNrVAtVES 

nab. — Gulf of Nicoya ; Puerto Portrero ; in 12 fm. coral 
sand ; Cuming, Hinds. — Mazatlan ; Menlce. — Do. ; common ; 

L'pool Col. 

Tablet 1839 contains 6 sp. different ages, olivaceous ashy- 
tint. — 1840, 6 sp. rich olive. — 1841. 3 sp. tint changing. — 1812, 
2 sp. black brown. — 1843, 5 sp. black fading into blue. — 1844, 
5 sp. dark lustrous shade. — 1845, 1 sp. olivaceous, spire inter- 
rupted by breakage. — 1846, 2 sp. dark, spire deformed, do. — 
1847, 2 sp. with opercula, one in situ, the other loose. 

Subgenus EUEYTA, JET. Sf A. Ad. 

Gen. vol. i. p. 225. — Shell with a false umbilicus, caused by the 

twisting of the columella. 
Buccinum, pars. Lam, 

455. EtTETTA rULGUEATA, Phil. 

Phil, in Zeit.f. Mai. 1846, p. 53, no. 2'i.—Menhe in do. (diagn. 

emend.) 1847, p. 181, no. 14. 
Euryta fulgurata, H. Sf A. Ad. Gen.\. 225. 
= Terebra arguta, Gould, Ilex. Sf Cal. Shells, p. 7, pi. 14, f 19. 

Shell very small, slender, with a variable number (12 — 18 in 
each whirl, like.) of fine sharp ribs (not nodose) often running 
in lines from the apex to the base ; interspaces elegantly 
undulated, shining and smooth except near the base where 
there arc some very fine spiral strife. Mouth rather elongate, 
lip not undulated, base strongly notched, displaying the false 
umbilicus. Colour extremely variable ; generally of a very 
light brownish tinge, elegantly penciled with reddish brown in 
irregular undulated markings, and a Ijrown spiral line border- 
ing the notch ; often without pencilings, of a uniform white, 
orange, or brownish purple, or with a light or dark band near 
the suture ; very frequently changing in pattern and colour at 
diflFerent ages. TJic first three whirls are smooth, and with 
the rest are slightly convex ; suture distinct. Spire very fre- 
quently covered with nearly roimd egg cases. Long. "74, 
1-ong. spir. '46, lot. '2, div. 23°. 
Sab. — Mazatlan, Philippi. — Do. Melchers, Menke. — Do. ; 

common, L'pool Col.* 

* Two shells in the British Museum from E. Africa, Capf. Owen, marked "T. 
aciculata, Oray," do not display any characters by which they can be separated 
specifically. 



MAZATLAN UNIVALVES 389 

Tablet 1848 contains 5 sp. pure wliite. — 1819, 4 do. French 
white. — 1850, 5 do flesh colour. — 1851, 4 do. orange.— 1852, 
5 do. orange brown, banded with light. — 1853, 4 do. Ught 
orange, do. — 1851, 1 sp. orange banded with light slate. — 1855, 
1 do. with purple. — 1856, 5 do. orange brown banded with 
white, faintly penciled. — 1857, 4 do. yellow banded with slate 
and white. — 1858, 5 do. slightly penciled. — 1859, 4 do. dark. 

Tablet 1860 contains 6 sp. purple slate, banded with white. — 
1861, 5 do. with orange tinge. — 1862, 4 do. brownish purple. — 
1863, 5 sp. nearly uniform slate. — 1864, 4 do. brown slate with 
white band. — 1865, 5 do. darker. — 1866, 6 do. with last whirl 
hght, penciled. 

Tablet 1867 contains 4 sp. white with slate band. — 1868, 6 do. 
faintly penciled. — 1869, 5 do. more penciled. — 1870, 5 sp. highly- 
penciled. 

Tablet 1871 contains 5 sp. colours blended, penciled.— 1872, 
3 sp. penciling dotted. — 1873, 4 do. penciling faint. — 1874, 5 do. 
finely zigzag. — 1875, 5 do. more distinct.^ 1876, 4 do. distant 
waves. — 1877, 4 do. highly developed. — In all 132 sp. of which 
each one perceptibly differs from the rest. 



456. EURYTA ACICULATA, JflfTW. 

PBuccinum aciculatum. Lam. An. s. Vert. vol. x. p. 175, no. 41. 
Terebra aciculata. Gray in Proc. Zool. Soc. 1834, p. 63. — Hinds 

in do. 1843, p. 166, no. 104. — Hinds in Sow. Thes. Conch. 

p. 183, no. 99, pi. 45, f. 104. 
Euryta aciculata, H. Sf A. Ad. loc. cit. 

Two dead specimens alone of this shell were found by Mr. 
Darbishire with Euryta fulgurata ; distinguished by long nodu- 
lous plaits at the upper portion of the whirl, in the last whirl 
slightly divided into two. Colour yellowish white with a brown 
spiral band on the nodulous portion, and a reddish band on the 
base. It does not agree with specimens received under the 
same name from the Bristol Museum, probably from the West 
Indies.* These are nearly related to A. Coseutini, Phil, from 
Naples. Menke considers them identical, Zeit. f. Mai. 1847, 

• "Our information of the W. Indian species i« moat barren," Hinds in Thet. 
p. 149. ? Is the Lamarckian shell the W. Indian species, and that from Aca- 
pulco distinct. Care must be talten not to confound it with Lamarck's Terebra 
aciculina (An. s. Vert. vol. x. p. 2.50, no. 22) which is Hue. cinereum of Bom, 
(v. Desk, in loo.) and Terebra cinerea of Thea, Conch, p. 180, no. 87 : — P. Z. S. 
1843, p. 165, no. 93. 



390 HAZATLiJil tlNIVALVES 

p. 181, but Hinds points out differences, Tlies. Conch, p. 184. 
Lo7ig. "5, long. spir. -32, lat. "IG, div. 30". 
Hah. — Acapulco, Sonsonati ; Mus. Cuming. — Xipixapi, Cum- 
ing. — Mazatlan ; extemely rare ; L'pool Col. 

Tablet 1878 contains 1 specimen, presented by B,. D. Darbi- 
shire, Esq. 

Family PLEUEOTOMID^. 

All the young Pleurotomidse examined bave tke apex normal, 
with about three whirls smooth and subtrausparent. The 
opercula in this Suborder, as in Proboscidifera, are very fre- 
quently repaired after fractui-e.* Whatever be their normal 
condition, they always reconstruct from a central nucleus : a 
circumstance which seems to shew that the variations in oper- 
cula are not of so much importance as in the shells ; the latter 
being almost always repaired after the normal pattern. 

Gekus PLEUEOTOMA, Lam. 

Journ. Hist. Nat. 1799, pars : canal elongated, operculum 
subtriangular, nucleus at the anterior extremity. 

TuiTis, (Humph.) Gray, Proc. Zool. Soc. 1847, p. 134.— 
H. ^ Ad. Gen. vol. i. p. 87. (Non Montf.J 

457. Pleueotoma funiculata, Val. 

Kien. Icon. Conch, p. 21, no. 18, pi. 16, f.\.—Rve. Conch. Ic. 

pi. 11, sp. 95. 
= P. olivacea, var. Rve. loc. cit. (a prim, man.) pi. 4, sp. 27; 

non Sow. Free. Zool. Soc. 1833. p. 136. 
Surcula (Turris) fuuiculata, H. Sf J. Ad. Gen. i. 88. 

The aspect of the ^Mazatlan shells is intermediate between 
the figures of Kien. and Eve. They differ from the figure of 
P. olivacea in the widely excavated space of the posterior sinus, 
and in the keeling of the whirls below it. The epidermis in 
the young shells is ashy, in the adult of a rich glossy olive. 
There are numerous coarse spiral strife, two of which appear 
above the suture. There are about 10 nearly obsolete costa?, 
rising into tubercles at the periphery. Nuclear whirls smooth. 

• V. Gray on Reproduction of Opercula, Ann. !)^al. SUt. 1834, p. 419. 



MAZATLAN TTNIYALVES 391 

The shells (of which I have examined about 100) scarcely vary, 
except slightly in acumination. The operculum is formed like 
an obtuse-angled triangle, with the base along the coliunella, 
nucleus near the canal, the other angles roimded ; reddish 
olive, strong, outside nearly smooth, with the base raised ; 
muscular scar deeply marked, but not corrugated. The young- 
est sp. is 1"1 long ; the largest (allowing for the decollation of 
the spire) measures long. 2 "48, long. spir. 1'34, lat. 1', div. 40". 
Sab.—^a.n Bias, Kiener. — Gulf of California ; in sandy mud; 
Lieut. Babb.—S. W. Mexico ; P. P. C— Mazatlan ; rare, in 
fine sand ; L'pool Col.— {The localities "Gulf ISTicoya and 
W. Coast Mexico, Hinds" assigned to P. ohvacea + funicidata 
by E,eeve, probably belong to this species.) 
Tablet 1879 contains 3 sp. different ages, of which one has 
the opercvdum in situ. — 1880, the largest sp. with its operculum, 
mended after fracture ; the original part is from a terminal 
nucleus, the new third from a central one. The shell has 
twisted its canal till it is '56 broad, forming a broad false 
umbilicus. Also a sp. incrusted, and with the canal desti'oyed 
by sponge ; yet with the operculum in sitii.— 1881, 2 opercula, 
one normal, the other with a subcentral nucleus. 

458. Pleukotoma maculosa. Sow. 

Proc. Zool. Soc. 1833, p. I'ib.—Rve. Conch. Si/sf. vol. ii. pi. 233, 
f. 8 -.— Conch. Ic. pi. 6, sp. 45.—M/ce. in Zeit. f. Mai. 1851, 
p. 19, no. 89.— (jS'on P. maculata, C. B. Ad. Contr. Conch. 
no. 4, p. 62. Jamaica.) 
DriUia maculosa, S. ^- A. Ad. Gen. i. 90. 

Shell very constant in form ; thin, slender ; of an ashy 
colour, more or less spotted or stained with reddish brown ; 
markings sometimes fine, sometimes in large dashes, sometimes 
almost wholly absent. Epidermis very thin, smooth, not 
glossy. First three whirls smooth ; the rest with one row of 
stoiit tubercles along the spire, which are rarely coloured ; the 
whole surface very finely spirally striated. Canal open, too 
long to rank satisfactorily with Drillia ; labrum smooth, sharp ; 
posterior sinus large, deep ; anterior slight, open. Operculum 
closely resembling that of PL funiculata, but longer in propor- 
tion, with the inner margin scarcely raised. About one in five 
of the opercula found were abnormal, with the nucleus central. 
The smallest sp. of 11 whirls, measures '68 ; the largest, (with 
15 whirls,) long. 1'96, long. spir. 1"13, lat. '57, div. 25". 



392 MAZATIAN UNIVALVES 

Sah.—W. Columbia ; in sandy mud, 16 £m. : Cuming. — Maz- 

atlan ; not uncommon ; L'pool Col. 

Tablet 1882 contains 8 sp. different ages and markings. — 
1883, 3 do. colour scarcely developed. — 1884, 4 sp. rather more 
slender.— 1885, 4 sp. mended after fracture, (one with a fresh, 
separate canal.) — 1836, 3 do. spire bent. — 1887, 1 sp. pierced by 
a Proboscidifer. — Six of the above sp. have the normal opercula 
in situ ; tablet 1888 contains 2 sp. with abnormal opercula in 
situ, and one normal operculum separate. 



Genus DEILLIA, Gray. 

Fig. Moll. An. p. 73, no. Z.—R. Sf A. Ad. Gen. vol. i. p. 89. 

Clavatula, pars, Lam. The operculum is Purpuroid in Clava- 
tula, Pleurotomoid in Drillia. Canal very short. The group 
is remarkable, among marine shells, for the number of black 
species. 



459. Deillia inceassata. Sow. 

Pleurotoma incrassata. Soto. Proc. Zool. Soc. 1833, p. 138. — 

Mull. S//n. Nov. Test. Viv. p. Wo.—Rve. Conch. Ic. pi. 9, 

f. 76.— ifyCe. in Zeit.f. Mai. 1851, p. 19, no. 90.— C. B. Ad. 

Pan. Shells, p. 141, no. 175. 
Crassispira (Drillia) incrassata, H. ^' A. Ad. Gen. i. 91. 
Pleurotoma Bottae, Kien. Icon. Conch, p. 33, no. 26, pi. 15, f. 2. 

The solitary Mazatlan specimen differs from Kiener's figure 
of M. Botta's supposed unique shell, in being quite black, with 
the labrum serrated, sharp, and incurved at the edge, then 
very much thickened ('18 in.) ; behind very thin, nearly tran- 
sparent. Posterior callosity distinct. The aspect of the shell 
is like a very large D. luctuosa, with very fine granulose radia- 
ting lines, about 18 in a whirl. A closely analogous form 
from the W. Indies, is probably the D. gibbosa, Chem. ele- 
gantly figured by Kien. Icon. Conch, pi. 16, f. 2. as his own 
species ; the error being corrected by Rve. sp. 30. Long. 1'64, 
long. spir. "83, lat. '68, div. 30". 
Ha7>. — Panama and Monte Christi ; in sandy mud 6 — 10 fm. ; 

Cuming.— 'Pa.na.ma, 1 sp. C. B. Adams. — Mazatlan, Botta : — 

do. ; 1 fresh sp. ; L'pool Col. 

Tablet 1889 contains the specimen. 



MAZATLAN UNIVALVES 393 

460. Deillia eudis, Sow. 

Pleiirotoma rudis, Sow. Proc. Zool. Soc. 1833, p. l^.—Mull. 

Si/71. Nov. Test. Viv. p. IQfd.—Rve. Co7ich. le. pi. 7, sp. 53.— 

C. JB. Ad. Pan. Shells, p. 146, no. 181. 
Crassispira (Drillia) rudis, H. ^ A. Ad. Gen. i. 91. 
Comp. P. excentrica, Soic. loc. cit.— JKt'e. loc. cit. sp. 58. — 

(Drillia e.) S. ^' A. Ad. Gen. i. 90. 

In a genus, the discrimination of whose species rests on 
minute details of sculpture, the figures in the Conch. Ic. are of 
but little help. The two shells from the Mazatlan boxes, with 
others obtained from a shop, probably from the same collection, 
agree in some points with each species, but are referred to 
D. rudis by Mr. Cuming. They are of a dull black, without 
white spots, with the upper keel nodulous in the upper whirls, 
a row of costal tubercles abnormally shewing at the suture, 
with spiral lines faintly nodulous below ; the whole surface 
minutely spirally striulated, more coarsely in the region of 
the notch ; the last whirl descending and then rising, making 
the axis excentric ; aperture ending in a notch with a very 
stout callosity rising above : labrum thin, shghtly incurved 
and serrated, with a strong rib behind ; labium distinct. 
Long. VI, long. spir. "6, lat. '48, div. (upper whirls) 48°. 
Hah. — Monte Christi ; under stones ; Cuming. — Mazatlan ; 

extremely rare ; L'pool Col. 

Tablet 1890 contains one specimen. 

461. Dktliia ateeeima, Sow. var. Melchehsi. 

Pleurotoma aterrima. Sow. Proc. Zool. Soc. 1833, p. 137. — 
Mull. Syn. Nov. Test. Viv. p. m.—Bve. Conch. Ic. pi. 12, 
sp. 100.— C. B. Ad. Pan. Shells, p. 138, no. 163. 

Crassispira (Drillia) aterrima, H. Sf A. Ad. Gen. i. 90. 

P=P1. maura, Val. in Kien. Icon. Conch, p. 59, no. 37, pi. 23, 
f. 1. (non Sotv.) 

= P1. Melchersi, 3/I-e. in Zeit.f. Mai. 1851, p. 20, no. 91. 

P + Pleurotoma discors. Sow. Proc. Zool. Soc. 1833, p. 137. — 
Mail. Syn. Nov. Test. Viv. p. 113.— ^ve. Conch. Syst. pi. 235, 
f. 14 -.—Conch. Ic. pi. 0, f. 38. 

Var. ? = P1. atrior, C. B. Ad. Pan. Shells, no. 16-1, pp. 138,308. 

= Pleurotoma rustica, P. P. C. Cat. Prov., non Sow. 
It is fortunate if Kiener's species, described from a specimen 

brought from Mazatlan by M. Botta, is not needed, as the 



394 MAZATLAN UNIVALVES 

name was pre- occupied by Sow. The inaccuracy of the figure 
in the Conch. Ic. and the variation in the number of spiral 
tubercular strife (in this species not a constant character,) excuse 
Menke for having redescribcd it. The P. atrior of Prof. 
Adams, described from a single specimen, appears to be char- 
acterized by the pale spiral stripe ; which, though rarely con- 
spicuous, and not noticed in the diagnosis of the species, may 
generally be seen inside the mouth, by holding the shell up to 
the light ; and in fine specimens is often clearly cUscernible on 
the last whirl. The P. discors scarcely differs in essential 
characters, though it is a much larger form. Shell with the 
entire surface very minutely spirally striated; with a prominent 
keel near but not close to the suture, which partially covers 
the principal row of nodules, 12 — 14. Below are several spiral 
lindse of which generally two, sometimes more, are prominent 
and granidar, the granules corresponding with the tubercles 
above. Sinus rather narrow and deep, in the middle of a large 
excavated area ; with the thick posterior callosity labral rather 
than parietal. A narrow horn-coloured band, sub-transparent, 
runs just above the tubercles ; (in one specimen broad, cover- 
ing the tubercles, = P. atrior, C. B. Ad.) Operculum broader 
than in D. luctiiosa, of a deep rich purplish red colour, very 
glossy inside. The spire outlines are Very convex in the adult, 
which has somewhat the aspect of a small D. rudis. The small- 
est adult sp. (decollated) measures "34 by '15. The longest, 
long. '72, long. spir. '36, lat. '24, div. 35". (anfr. sup.) 
The broadest ep. measures lat. '28, div. 40". 
Sah. — Monte Christi ; under stones, Cuming. — Panama; 

14 sp, do. at low water mark ; C. B. Adams. — Mazatlan ; 

not common, often incrusted with coralline, very rarely with 

mud ; L'pool Col. 

Tablet 1891 contains 8 specimens, different ages. — 1892, 4sp. 
spire more elevated. — 1893, 3 sp. acuminated ; sciUpture some- 
times nearly obsolete. — 1894, 3 sp. dwarf state. — 1895, 2 sp. 
light band developed. — 1896, 2 sp. with opercula, one normal, 
the other with nucleus subcentral ; and one separate operculum. 

462. PDbiilia ceeithoidea, n. s. 

ID. t. "D. aien'imw" simili; sed carituB infrasufurali ca rente, 
(interdum strice majore hie monstrante,) areA sinus angustiore, 
hand excavata, superiore ; monilihus spiralibus in basi pluribus ; 
tuberculis in spird magis conspicuis ; labro serrafo, sinu pro- 



MAZATIiAU UNIVALVES 395 

fundo, ad aperturam contracto, spiram suhascendente, callo 
parietali minore ; zona translucidcs carente. 

Tvro perfect specimens and one broken were found of this 
species, wticli resembles D. aspera, Hinds, and D. tbiarella, 
Val. but does not accord in sculpture with either. It is known 
at once from D. aterrima by the position of the slit, which is 
much nearer the suture and slopes upwards. This causes more 
of the tubercles to be seen on the spire. Long. *64, long. spir. '4i, 
lat. -26, div. 35°. 
Sah. — Mazatlan ; 3 sp. only ; L'pool Col. 

Tablet 1897 contains the perfect specimen. In the young 
shell, the slit is quite close to the suture. 

463. Deillia zonulata, Rve. 

Pleurotoma cincta. Sow. Proo. Zool. Soc, 1833, p. 136. (Non 

Lam. An. s. Vert, vol ix. p. 347, no. 8 : — Kien. Icon. Conch. 

p. 60, no. 38, pi. 19, f. 3. Mauritius.) 
Pleurotoma zonulata, Mve. Conch. Syst. 1848, pi. 234, f. 10 : — 

Conch. Ic. pi. 6, f. 39.— C. B. Ad. Pan. Shells, p. 148, no. 184. 
Crassispira (Drillia) zonulata, S. iSf A. Ad. Gen. i. 91. 

This pretty little species is known from D. aterrima, not only 
by the yellow neck-lace on the spire and the yellow belt on the 
base, but by the comparative smoothness of the infrasutural 
groove, and the shape of the tubercles, which are very narrow, 
but gi-eatly elongated spirally. Long. "65, long. spir. '39, 
lat. '25, dAv. 35°. 
jffai.— Monte Christi and Xipixapi ; in sand and gravel 7 fm. ; 

Cuming. — Panama ; 2 sp. C. B. Adams. — Mazatlan ; 1 sp. ; 

L'pool Col. 

Tablet 1898 contains the specimen. 

464. Deillia monilifeea, n. s. 

D. t. turritA, nigrd, aurantio gemmatd ; anfr. subplanatia, 
omnino minufissime et confertissime spiraUfer striulatis ; regione 
infra-siUurali haiul excavata ; stria juxta suturainvix tv.hercu- 
lata ; circa pcripheriam zona aurantiai'd, tuberculis parvis, 
'•irciter xii. ornatd ; et infra, striis spiralibus, circiter v., tuber- 
'•idis minimis convenientibus ; tuberculis omnibus et striis 
plerumque aurantiacis ; aperturd intus, nisi ad zonam subdia- 
phanam, purpureo-nigrd. 



396 MAZATUJT UNITALVES 

Only one specimen, not quite mature, was foxmd of this 
species, wkich resembles D. aterrima, zonulata, &c. but is 
easily recognized by the non-excavation and extremely faint 
keeling of the area of the sinus ; and the colour, which pre- 
sents one large and several minute rows of connected orange 
tubercles upon a black ground. Long. "64, long. spir. "41, 
lat. '23, div. (anfr. prim.) 30". 
Hah. — Mazatlan ; 1 fresh adolescent sp. ; L'pool Col. 

Tablet 1899 contains the specimen. 



465. Deillia alboyallosa, n. s. 

D. t. adolescente suhturrita, nigra ; casta rotundatd, alhida, 
expressd, spiram ascendenfe ; marginihus spircB suhinciirvatts ; 
totd superficie confertim spiraliter striulatd, striulis in aream 
sinus hand excavatam magis expressis ; casta alba suturam 
approximante, haud attingente, undato-tuherculata ; serie tuber- 
culorum, circiter xvii., angustorum, radiatim elongatorutn, vix in 
spird manstrante ; striis spiralibus circa hasim, quarum super- 
iores tuberculoses, tuber culls alter is convenientibtui : t. adulta 
anfr. iii.—iv. omnino costce albce carente ; vice ejus serie tuber- 
cnlorum infrasuturalium, tubercuUs peripherialibus anfractus 
alterius convenientium ; anjr. ult. parum descendente ; mar- 
ginihus spirce excurvatis ; aperturd siibovali ; sinupostico lato, 
haud profunda ; nigro-fuscd, prope sinum posticum maeulis 
suhdiaphanis ornatd. 

Only one specimen of this shell was found in the Mazatlan 
collection. The spire is rather compact, last whirl somewhat 
projecting, white band not quite touching the suture, and 
peripheral tubercles shewing more in the early than in the 
latter whirls. A specimen of unknown locality in Dr. Gould s 
collection appears to be conspecific, but is larger, spire rather 
more elevated, markings not so decided (perhaps rubbed) and 
with the band smooth and yellowish. A shell however appears 
in the Ciimingian Museum, of uncertain history, which begins 
exactly like the Mazatlan specimen, with the white ridge 
round about six whirls ; after which it suddenly changes, 
developing three whirls and a half without any white ridge, 
and presenting the general appearance of D. rudis. Even this 
specimen is not quite mature, as is shewn by the sharp un- 
formed labrum. The faint, semi-transparent spots above the 
tubercles round the periphery are only seen by holding the 



MAZJLTLAN TTNIVALTES 397 

shell up to the light. The Mazatlan specimen, yovmg state, 
measiires hng. "42, long. spir. '22, lat. "19, div. SO"—'©''. 

Mr. Cuming's sp. „ 1-08, „ •&!, „ -39, „ 300. 
^<t6.— Mazatlan ; 1 fresh adolescent sp. ; L'x)ool Col. 
Tablet 1900 contains the specimen. 

466. Deillia albonodosa, n. s. 

D. t. turrita, nigra, gracili ; epklermide tenui, IcBvi, fused, 
induta ; anfr. iii. nucleosis, vii. normalibus, parum excurvatis ; 
tuherculis valde extantihus, cirdter viii. acutioribus, serie peri- 
pheriali arnata ; aliter sublcevi, striis distantibus et striulis 
confertis minimis spiralibus vix ornatd ; area infrasuturali 
hand exeavatd ; aperturd subovali ; labro aeiito, vix serrato ; 
sinupostico profunda, parvo, rotundato, const ricto ; supra, intus 
suturam, callosd ; labio parvo, Icevi. 

This species resembles Clavatula cajlata and CI. micans, 
Hinds, and also a species from Honduras. The sculpture is 
extremely faint, except the strong row of tubercles. Long. '51. 
long. spir. "28, lat. '17, div. 30". 
Sab. — Mazatlan ; 2 sp. and fragments : Upool Col. 

Tablet 1901 contains a perfect specimen. 



467. Dbillia luctuosa, Sinds. 

Clavatula luctuosa. Hinds, Proc. Zool. Soc 1843, p. M):—Voy. 

Sulph. Moll. p. 18, no. 58, pi. 6, f. 4. 
Pleurotoma luctuosa, Rve. Conch. Ic. pi. 18, sp. 149. 
Crassispira (DriUia) luctuosa, H. Sf A. Ad. Gen. i. 91. 
Non PL luctuosa, D'Orb. B. M. Cat. Cub. Moll. p. 31, no. 370. 

This unpretending little species is easily recognized by its 
black colour and faint sculpture. A row of small tubercles 
ascends the spire, scarcely discernible on the last whirl, which 
(as in D. rudis) descends and rises again at the mouth, making 
the spire-outhnes curvilinear. The first three whirls are smooth. 
Surface with extremely fine lines of growth, faintly decussated 
by spiral striulae. Labrum sharp, not serrated, with a swelling 
behind ; anterior sinus veiy distinct, as in Strombus ; pos- 
terior notch deep ; sutural callosity large, joining the well- 
developed labium. Operculum shaped as in D. maculosa, 
with more or less of a reddish tinge. Spire generally incrusted 
Nov. 1856. U 



398 MAZATIAN UNIVALVES 

with blackish mud, sometimes bearing round flat egg-cases, 
I>ierced in the middle. Long. "61, long. spir. *32, lot. '25, 
div. (anfr. sup.) 40". 

Hah. — Baj" of Guayaquil; Gulf of Magdalena, California, 
5 — 22, fm. ; Hinds. — Mazatlan ; not uncommon ; L'pool Sf 
Havre Coll. 
Tablet 1902 contains 5 sp. immature. — 1903, 6 sp. adult. — 

1904, 2 sp. mended after fracture. — 1905, 1 sp. with egg-cases. — 

1906, 1 sp. -with operculum ; also 2 separate opercula, one 

normal, the other with sub-central nucleus. 



468, PDeillia Hanleyi, n. s. 

?D. t. subacuminata, nigra, epidermide tenui nigro-cinered, 
indutd ; anfr. .?xi. suhplanatis ; canali infrasuturali angusto 
et totd superjicie tenuissime spiraliter striatis ; carina parum 
prominente juxta suturam ; costuUs radiantibus concinnis, valde 
aeufis, circiter xv. vix declivihus ; aperturd nigrd ; t^ adolescente 
sinu parvo ; t. adultd ? 

Somewhat resembles the young of D. luctuosa, but is known 
by the fine costse, continued nearly to the base and the infrasu- 
tural keel. It has some points in common with Defrancia 
caelata. Hinds, but its analogies seem to be with D. aterrima, 
&c. The only specimen found (which has its upper whirls 
smooth) is not quite matm'c, and measures long. '38, long, 
spir. -24, lat. '15, rf/i). 32". 
Hah. — Mazatlan ; 1 fresh sp., L'pool Col. 

Tablet 1907 contains the specimen. 

469. Deillia , sp. ind. 

Tablet 1908 contains a shell, too much rubbed for description, 
and a spiral fragment which may be couspecific ; reddish 
brown, with a white spiral baud. It closely resembles a W. 
Indian species. Shell with normal whirls, and a rounded 
vertex of 3 smooth whirls. Long. '35, lat, '14. 
Hah. — Mazatlan ; extremely rare, ofl" Spondj'lus ; L'pool Col. 

470. Deillia , sp. ind. 

Tablet 1909 contains a specimen, too much worn for des- 
cription, of a small tuvrited species of about 7 whirls, measuring 



MAZATLAN UNIVALVES 



399 



•17 "by "07. It has a very broad, excavated infrasutural area, 

with a faint keel above, and one row of small tubercles below, 

shewing on the spire, and other smaller tubercular spiral lines 

beneath. 

Sab.— Mazailan ; 2 sp. off Chama and Spondylus ; L'pool Col. 



Tablet 1910 contains an imperfect operculum, which may 
belong to a large Drillia ; of a rich, dark brown colour, rather 
undidated, with very faint marks of growth ; inside with a 
large, nearly smooth scar bounded by a ridge. 

Tablet 1911 contains a very small operculum of somewhat 
concentric elements ; very thin ; not unlike that of Clavatula 
bimarguiata, figured in E. Sf A. Ad. Gen. vol. i. pi. 10, f. 5a. 

Genus CLATHUHELLA.* 

Defrancia, Millet, Ann. Soc. Linn. Par. 1S26.— Gray, Fig. 

Moll. An. p. n.—PMl Sandh. Conch, p. 137.— J?. ^- A. Ad. 

Gen. vol. i. p. 95,— (Non Defrancia, Mull. Ind. Moll. Groenl. 

p. 12,=Bela, Leach : — nee Defrancia, Bronn. 1825.) 
Clavatula, pars. Hinds.— The Lamarckian genus is restricted 

by Gray to the species which have a Pui'puroid operculum. 

These shells are said to have none. 

471. Clatiiukella eava. Hinds. 

Clavatula rava, Einds, Proc. Zool. See. 1843, p. 39:— Fo^. 

Siilph. Moll. p. 17, no. 53, pi. 5, f. 18. 
Defrancia raua, E. &f A. Ad. Gen. i. 96. 
PNon Pleurotoma rava, Roe. Conch. Lc. pi. 28, sp. 250. (Isl. 

Mindanao, Philippines, Cuming.) 

Two beautiful specimens were found, exactly agreeing with 
the accurate figure and description in the Voy. Siilph. Moll. 
As Reeve's shell is from the Philippines, and differs in some 
particulars from this, it is probably a distinct species. Shell 
orange, with two purple brown bands ; one in the infrasutural 
channel, which is ornamented with very tine undulated spiral 
striulse ; the other continuing the suture round the base, and 
staining the inside of the aperture. Labrum and labium armed 

• This name is proposed for a convenient group of the Mangelia tribe; the 
name Defrancia, previously in use, being preoccupied, v. supra, p. 6. 



400 MAZATLAN rKITALTES 

with denticles inside ; notch deep but narrow. Whirls rounded, 
with 11 — 13 radiating costse, decussated by spiral strife, of 
which about 5 shew on the upper whirls. Long. "38, long, 
spir. -23, lat. '17, div. 32°. 

Mab.—GviH of Nicoya ; 18 fm. mud ; Hinds. — Mazatlan ; 2 sp. 
only ; L'pool Col. 

Tablet 1912 contains the largest specimen. 

472. Clathceella aueea, n. s. 

CI. t. valde aUenuata, aured, ejndermide ienui, inierdum 
aurantid, tinctd ; anfr. ix. convexis, canali infrasuturali latim'e, 
lineis incrementi arcuatis distinctis ornato ; tubercidis costcs- 
fonnihus vuL — x. rotundatis in peripheriam, secundum Uneas 
spirales, iii. in spird, tuherculatis ; anfr, ult. costuUs radianti- 
hus infra tiiberculos confertis, lirulis confertis spiralihus tuher- 
culatis ; aperturd et canali suhelongatis ; lahro varicose, crasso, 
intus dentato ; sinu postico prof undo, angusto, spirant suhascen- 
dente, supra calloso ; labia tenui, dentato. 

Approaches CI. bicanalifera, Soto, but differs in the narrow 
slit, and singularly decussated groove. The varix is extremely 
thick. The costular tubercles which appear ou the spire, do 
not correspond with the narrow crowded ribs which appear on 
the basal portion. It is more slender than CI. rava, with dif- 
ferent colour and sciilpture. Long. "54, long. spir. '26, lat. "18, 
div. 25°. 
Sah. — Mazatlan ; 1 fresh specimen ; L'pool Col. 

Tablet 1913 contains the specimen. 

Genus MANGELIA, Bisso. 

Sist. Nat. Eur. Mer. vol. iv. p. 219, 1826 :— do, Leach, ms.— 
S. S^'A. Ad. Gen. vol. i. p. 99. (Non Mangelia, Rve. Conch. 
Je. = Cithara, Schum.) 

MangUia (err. cor.) Phil. Handh. Conch, p. 38. 

473. Mangelia Pacpticostata, var. subangulata. 

M. t. rubro fused, stibturritd ; apice hand acutd, anfr. iii. 

Imnbus ; arfr. normalibus iv. + , excurvatis ; costis x. 

acutionbus, subundulatis, ad basin continuis, lineis plerumque 
sjiiram oblique ascendentibus, ad peripheriam subangulafis ; 



MAZATLAN UNIVALVES ^1 

inter stitiis latis, spiraliter vix striulatis, hasi vix striata j 
aperturd suhpyriforma ; lahro acuta, secundum costas vtx 
sinuato : labio inconspictio. 
Mangelia acuticostata, Proc. Zool. Soc. June, 1856. 

Eesembles M. neglecta, C. B. Ad. wliicli however is de- 
scribed as having an elevated spiral line on the middle of the 
whirls, and basal strise. Lo)ig. 'ISS, long, spir.'i^^, lat.'(yi, 
div. 35". 
Sa6.— Mazatlan ; 1 sp. oflf Spondylus ; ri^ool Col. 

Tablet 1914 contains the specimen. 

Genus CITHAEA, Schmn. 

Ess. no. 106, l%VJ.— Woodw. Man. p. 115. 

Cythara, H. Sf A. Ad. Gen. vol. i. p. 98. 

Mangelia, Rve. Conch. Ic. (non Eisso) maxuna pars. 

474. PCiTHAEA , sp. ind. 

Tablet 1915 contains a liroken shcU with 7 long, straight, 
sharp ribs and very crowded spiral strise ; mouth sublinear ; 
labrum thickened, "except at the notch. There is no trace of 
teeth within. 
J2a6.— Mazatlau ; 1 sp. off Spondylus ; L'pool Col. 

Family CONIDtE. 

Genus CONUS, Linn. 

The Mazatlan Cones do not appear to be rich either in 
species or individuals ; nevertheless, if not valuable to collec- 
tors, they were interesting through possession of the epidermis, 
and often of the opercula. These are very small for the shell, 
elongated and narrow ; with the apex terminal, usually decol- 
lated, and often much broken. ^VTicn repaired, as in other 
families, it sometimes assumes the concentric type. 

475. CONUS EEGULAEIS, SoW. 

Conch. HI. pi. 29, -f. 29, pi. 36, f. 45.— i2w. Conch. Ic. pi. 26, 
sp. 126.— ia;w. An. s. Vert. vol. xi. p. 132, no. l^fd.—Kien. 
Icon. Conch, p. 124, no. 103, pi. 23, f. 3, \vc.—Mke. in Zeit. 



402 MAZATLAN UNIVALVES 

/. Mai. 1851, p. 22, no. 97— C. B. Ad. Pan. Shells, p. 110, 

no. 120. 
Leptoconus regularis, H. Sf A. Ad. Gen. i. 252. 
Comp. Conus arcuatus, Srod. Sf Sow. Zool. Journ. vol. iv. 

p. 379.— ZooZ. Beech. Toy. p. 119, pi. 36, f. 22.—Bve. Conch. 

Ic. pi. 15, f. 77, in. (Mazatlan.) 

Tkis was tlie least uncommon of tlie Mazatlan Cones, but 
few of tke specimens were in a state attractive to collectors. 
The spire outlines are generally incurved. It is known at once 
by the conical form, and dark tessellations over a lighter ehes- 
nut ground. Epidermis extremely thin, adherent, almost 
smooth ; on the sinus area, with coarse ridges of growth, 
surmounted by fine bristles in spiral rows. The animal pro- 
bably retires some way into the shell, as the epidermis is not 
removed on the labium within the aperture. Operculum out- 
side more or less concave ; with the muscular scar shewing 
non-angular ridges of growth. The largest of the specimens 
measures long. 2"38, long. spir. "4, lat 1"28, div. 120°. 

An elevated sp. „ 2-38, „ '57, „ 1*12, „ 84". 

JIab. — Gulf Nicoya and Panama ; in soft mud 7 — 23 fm. ; 

Hinds. — Taboga ; 1 impei'fect sp. C. B. Adams. — Gruaymas, 

Lieut. Green. — Mazatlan ; not common ; L'pool Col. 

Tablet 1916 contains 3 sp. broad form. — 1917, 3 sp. elongat- 
ed. — 1918, 1 do. spire outlines neai'ly straight. — 1919, 1 sp. 
spire very much elevated. — 1920, 2 sp. after hot acid, shewing 
colour. — 1921, 4 sp. curiously deformed after fracture ; one 
with a spiral canal. — 1922, 1 normal and 2 abnormal opercula. 



476. Conus puepueascens, Brod. 

Proc. Zool. Sor. 1833, p. 54.— 3/«ZZ. S>/n. Nov. Test. Vtv. p. 21. 

—Soiv. Conch. III. pi. 25, f Vi.—Rve. Conch. Ic. pi. 19, 

f. 105. — Desh. in Lam. An. s. Vert. vol. xi. p. 131, no. 193. — 

Kien. Icon. Conch, p. 189, pi. 39, f. 2, pi. 61, f 3.— C. B. Ad. 

Pan. Shells, p. 108. no. 118. 
Chelyconus (Leptoconus) purpurascens, S. 6f A. Ad. Gen. i. 

254. 
+ Conus comptus, Gould, CaVSf Mex. Shells, p. 14, pi. 14, f. 123. 
.'+ Conus interruptus. Brod. Sf Sow. Zool. Journ. vol. iv. 

p. 379 -.—Zool. Beech. Voy. p.'119, pi. 33, f. 2.— Eve. Conch. 

Ic. pi. 22, f 125. 



MAZATLAN UNIVALVES 4D3 

This shell may be the C. achatinus of Menke, instead of the 
next ? species. It is closely allied to that and several other 
forms. The epidermis, when very fresh, is thin, dark olive, 
with more or less conspicuous scaly ridges of growth, crossed 
by spiral lines of short bristles, of which one is conspicuous on 
the shoulder ; in the sinus area, imbricated. A swollen sp. 
measures long. 2*18, long. spir. '33, lat. 1'37, div. 110°. 

An elongated sp. „ 2-07, „ '3, „ 1-07, „ 110°. 

Sah. — Is. Annaa, Sowerby. [?] — Panama ; in sandy mud in 
clefts of rocks ; Cuming. — Do. ; 12 sp. under stones, at ex- 
treme low water mark ; C. B. Adams. — San Bias, Sinds. — 
Mazatlan ; extremely rare ; Upool Col. 
Tablet 1923 contains 3 sp, somewhat varying.— 1924, 3 sp. 
approaching C. regaUtatis. 

477. CONXJS EEGALITATIS, Sow. 

Proc. Zool. Soc. 1834, p. 19. — Milll. Sijn. Nov. Test. Viv. 

p. \m>.—Sow. Conch. III. pi. 57, f. Sl.—Rve. Conch. III. pi. 40, 

f. 218. — Lam. An. s. Vert. vol. xi. p. 133, no. 192. — Kien. 

Icon. Conch, p. 237, pi. 39, f. 3.-0. B. Ad. Ban. Shells, 

p. 109, no. 119. 
P = C. achatinus, Mke. in Zeit. f. Mai. 1847, p. 183, no. 23.* 

(non Brug.) 
Chelyconus (Leptoconus) regalitatis, B[. Sf A. Ad. Gen. i. 254. 
?An C. purpurascens, var. 

The few specimens belonging to this form were soon caught 
-<ip by collectors. It is distinguished by the shape and paint- 
ing ; but the Mazatlan specimens were not so constant in 
these respects as to have authorized the separation. At the 
same time they were not nu.merous enough to warrant me in 
imiting what those who have paid particular attention to the 
tribe have had grounds for separating. Epidermis generally 
smoother than in C. purpurascens. Long. 2'1, long. spir. '37, 
lat.l-1, div. 11°. 

Sab. — Real Llejos ; in clefts of rocks on sandy mud ; Cuming. 
— Panama ; 9 sp. under stones at extreme low Mater, (one 
measuring 3) ; C. B. Adams.— S. W. Mexico, P. P. C— 
Mazatlaii ; extremely rare ; L'pool Col. 
Tablet 1925 contains the finest specimen. 

• Dr. Menke also quotes in his list the well known C. omaria, Zeit.f. Mai. 1851, 
p. 23, no. 09, as from Mazatlan, though he informs his readers that it is generally 
thought to be E. Indian. 



404 MAZATLAX tTNIVAtVES 

[478. CoNUS ABENATTJS, Brug. 

Diet. no. IQ.—Billw. Besci\ Cat. vol. i. p. 400, no. S^.—Rve. 

Conch. Ic. pi. 17, f. 92. — Lam. An. s. Vert. vol. xi. p. 22, 

no. 18. 
For other references, v. Desk, in loc. 

One extremelj' worn specimen of tliis well-known E. Indian 
shell, was found in the Cone box. It probably came in ballast. 
It measures 1 "98 by I'l. 
Jffah. — Ceylon and Philippiaes, auct. — IMazatlan ; 1 dead sp. ; 

L'pool Col. 

Tablet 1926 contains the specimen.] 

479. Co2rrs puxcTicrLATUs, Swflss. 

Encycl. Meth. Vers. i. pt. 2, p. IQ^.—Rve. Conch. Ic. pi. 20, 

sp. IIQ.—Kiist. Mart. p. 41, no. 28, pi. 6. f. S.—Kien. Icon. 

Conch, p. 172, no. 146, pi. 60, f. 1. — Lam. An. s. Yert. vol. xi. 

p. 85, no. 114, yar. I.— Wee. in Zeit. f. Mai. 1851, p. 23, 

no. 98. 
Chelyconus (Leptoconus) puncticulatus, S. SfA. Ad. Gen. i. 254. 

Lam. gives this name as of Brur/. and quotes it from China. 
There is a closely allied E. Indian species, differing priacipally 
in having white between the dots on -the spiral lines. The 
Mazatlan shell is more or less swollen, with nodulous spiral 
lines near the base ; inside lavender. The epidermis is thin, 
nearly smooth, adherent. — The operculum outside is concave, 
with regular lines of growth ; the muscular scar displays a 
few strong, angular ridges of growth. The largest specimen 
measures long. 1"3, long, spb: '25, lat. "82, div. 110°. 

A broad sp. „ 1-2, „ '23, „ -78, „ 110". 

An elongated sp. „ 1-28, „ '3, „ '72, „ 90°. 
Hab. — Salango and St. Elena ; sandy mud, 5 — 9 fm. ; Cuming. — 

Mazatlan ; rare ; L'pool Col. 

Tablet 1927 contains 3 sp. normal state. — 1928, 3 sp. with 
red-brown patches small. — 1929, 1 sp. patches diffused, resem- 
bling the young of C. purpurascens. — 1930, 3 sp. slender form. — 
1931, 3 sp. stout form. — 1932, 2 sp. after hot acid, shewing 
colour. — 1933, 4 sp. mended after severe fracture ; in one the 
canal is twisted to the right, occupying the place of the ante- 
rior sinus in Strombus. — 1934, 1 operculum. 



MAZATLAN rXIVALVES 405 

480. Coxrs gladiatoe, Brod. 

Proc. Zool. Soc. 1833, p. oo— Mull. Syn. Nov. Test. Vlv. 
p. 121— Sow. Conch. III. pi. 33, f. M.—Bve. Conch. Ic. pi. 22, 
f. 127.— Kien. Icon. Conch, p. 25, pi. 15, f. 4, pi. 109, f. 4.— 
C. B. Ad. Pan. Shells, p. 105, no. 114. 
Ekizoconus (Leptoconus) gladiator, H. Sf A. Ad. Gen. i. 252. 

This unpretending species is li:no\ni wlien fresli by its ex- 
tremely tbiick, somewhat deciduous epidermis, wliicli lies in a 
spongy mass, with ridges of growth, and distant spiral rows of 
hairs, which often group into pairs. It is thick on the spire, 
with a row of scaly bristles over the tuberculous shoulder. 
Sinus area spirally striated. The elevation of the spire ia 
extremely variable. Operculum resembling that of C. puncticu- 
latus, but larger, less bent, and commonly decollated. The larg- 
est sp. measures long. 1"77, long. spir. '17, lat. 1'12, div. 14/)". 
Aflatsp. „ 1-26, „ 0, „ -83, „ 183°. 

A slender sp. „ VU, „ '2, „ '9, „ 130°. 

.ffai. = Panama ; in sandy or soft mud, in the clefts of rocks; 
Cuming. — Do.; at low water mark, mostly under stones 
which were more or less mingled with sand, not uncommon ; 
C. B. Ada-ms.-S. W. Mexico. P. P. C— Mazatlan ; rare, 
generally encrusted with coralline, Bryozoa, &c. ; L'pool Col. 
Tablet 1935 contains 3 sp. stout, elevated.— 1936, 3 do. nor- 
mal.— 1937, 3 do. flat.— 1938, 3 sp. slender, flattened.— 1939, 
3 do. elevated. — 1940, 3 sp. mended after fracture. — 1941, 1 sp. 
with rough portion of epidermis removed, resembling C. regali- 
tStis. — 1942, 2 sp. epidermis removed. — 1943, 4 opercula, of 
which one is normal, and another is mended from a sub-central 
nucleus. 

481. Coxrs Nux, Brod. 

Proc. Zool. Soc. 1833, p. bi^.—Mull. Spn. Nov. Test. Viv.— 
p. 120.— ^ow. Conch. 111. pi. 32, f. Zl.—Rve. Conch. Ic. pi. 20, 
f. WO.— Desh. in Lam. An. s. Vert. vol. xi. p. 129, no. 185.— 
Kien. Icon. Conch, p. 47. pi. 11, f. 3, pi.. 102, f. 2.—C. B. Ad. 
Pan. Shells, p, 106, no. 116. 

Coronaxis (Conns) nux, H. Sf A. Ad. Gen. i. 248. 

Most of the Mazatlan specimens are distorted, but may be 
recognized by the deep violet stain at the base, and the nearly 
smooth epidermis, which is adherent, with faint stria; of 
growth. The spire is tuberculous, sometimes flattened. The 



406 MAZATLAJf rXITALTES 

operculum is externally deeply concave ; inside simple. The 
largest specimen is only 1"1 long. One -with, elevated spire 
measures long. 1'02, long. spir. '14, lat. "63, c?ii'. 128°. 

A flattened sp. „ I'Ol,, „ -06, „ '78, „ 170". 

Sab. — Galapagos, Cuming. — Taboga, 2 sp. C. B. Adams. — 
Mazatlan ; extremely rare ; L'pool Col. 

Tablet 1944 contains 2 sp. normal, and an operculum. — 1945, 
2 sp, distorted. 



482. CONTJS PSCALAEIS, Val. 

Rec. Obs. Hiimh. Sf Bonpl. vol. ii. p. 338. — Kien. Icon. Conch. 

p. 158, no. 133, pi. 88, f. 5. 

Tablet 1946 contains a rubbed small specimen, "54 in length, 
which perhaps belongs to this species. 
Hah. — Acapulco, Valenciennes. — ? Mazatlan ; 1 dead sp. L'pool 

Col. 



483. ?? Coifus , sp. ind. 

Tablet 1947 contains the spiral part of a thin shell with 4 
smooth rounded nuclear whirls, rather pi'ojecting, and 4 flat- 
tened projecting normal whirls, spotted with purple brown ; 
smooth, with raised, somewhat nodose bands on each side of 
the suture. It may possibly belong to Pyrella, Swains. 
[ = Tudicla (Bolt), HS,- A. Ad. vol. i. p. 151.] 

Tablet 1948 contains the distorted operculum of a Conus, of 
concentric elements, with one end elongated. 



SuBOEDEE PEOBOSCrDrFEBA. 

■ Family SOLAEIAD.^. 

The shells of this family have the nuclear whirls slanting 
and sunken, as pointed out hy Woodward. The shape agrees 
in Solarium, Torinia and Bifrontia. In Plnlippia, G-rai/, the 
nucleus has the same character, but is larger in proportion, 
more globular, with one conspicuous whirl. A similar differ- 
ence obtains between Chemnitzia and Odostomia in Pyramidel- 



MAZATLAK UKIVALVES 407" 

lidse, to wliieh family these very different-looking shells seem 
allied. Tke animal of PhUippia is said however to be a 
Scutibranch Trochid. 



Gentjs TOEINIA, Gray. 

S. Sf A. Ad. Gen. vol. i. p. 242. Shell rounded : operculum 
trochiform, as in Bifrontia. 



481. ToEiNiA PvAEiEGATA, Lam. 

Solarium variegatum, Lam. An. s. Vert. vol. ix. p. 99, no. 6. 
Trochus perspectiviunculus variegatus, Chem. Conch. Cab. 

vol. V. pi. 173, f. 1708-9. 
= Euomphalus radiatus, Mke. in Zeif.f.Mal. 1850, p. 170, 

no. 27. 
Comp. Solarium, sp. ind. c, C. B. Ad. Pan. Shells, p. 190, 

no. 272. 

Menke states that his shell is that of Chemnitz, but is not 
the Solarium variegatum of Lamarck as Kiener and Deshayes 
suppose. If the Lamarckian species, which is said to be from 
N. Zealand, be distinct, the name of 3fke. is certainly shorter 
than that of Chenin. which is adopted however by Billw. Rec. 
Sh. p. 783, no. 59. On a very close comparison with one of the 
BSi-badoes species, (supposed to be the Lamarckian shell,) I 
am unable to detect any specific difierence. Mr. Cuming has 
the same form from Isle Annaa. 

The Mazatlan shell differs from Torinia areola, Chemn. 
( = Solarium tesscUatum, Desh. olim ; v. Lam. An. s. Vert. 
vol. is. p. 100, no. 8) in having a rounder base, and in not 
having the first row of granules below the suture white. Of 
this species, the locality of which was not known by Desh, I 
have a specimen answering exactly to the description from the 
W. Indies. The name is given in the Br. Mus. to a specimen 
sent from California by Lady K. Douglas. Tlie G-ulf species 
has a very rounded outline, with numerous spiral ribs of which 
generally four appear on the spire. They are rendered granu- 
lose by strong stria; of growth. The umbilicus has two strong 
granulose spiral keels, which crenulate the subquadrate mouth. 
The operciilum, which was preserved in four of the specimens, 
is very conical, and has about 10 turns bounded by raised 
ridges. Colour purplish brown tessellated with light. Epider- 



408 MAZATLAN TJXITALVES 

mig rather tliin, conspicuous, adherent, of a horny olivaceous 

colour. Long. "52, long. spir. "32, lat. '63, div. 90". 

Sab. — Mazatlan ; 5 sp. very perfect ; L'pool Col. (For other 

localities , V. supra.) 

Tahlet 1949 contains the most characteristic specimen. 

485. ToEiNiA Pgeanosa, Val. 

Solarium granosum, Vcd. Bee. Ohs. vol. ii. p. 269. Described 
as the living analogue of the Italian fossil, S. milligranum. 

Comp. Solarium fenestratum, Hinds. 
Tablet 1950 contains a fragment of the base of a very distinct 

species. It is flat, with numerous strongly granular spiral 

rows, and deeply cut broad interstices. 

Hah. — Acapuleo, Smnholdt Sf Bonpland. — ? Mazatlan ; ex- 
tremely rare, off Spondylus ; L'pool Col. 

Family PYEAMIDELLID^. 

This family, the smaller forms of which are so abundant in 
our own seas that Clark speaks of it as a "truly British group, 
which far outnumbers the discoveries of any other coimtry," 
is probably well represented in most places, but has escaped 
attention in consequence of the minuteness of most of its 
members. While the assiduous and almost exhaustive labours 
of British malaeologists have eliminated 44 species, of which 
Clark regards 20 as spurious, the mere refuse from a few 
Mazatlan shells has displayed forms which have required the 
enumeration of 72 species to contain them. AU the sectional 
fonns described from our own seas are here represented, with 
the addition of some not hitherto distinguished. While rich 
in species however, the materials at our command were very 
sparing in specimens, only one (ChrysalUda communis, C. B. 
Ad.), which appears to be littoral in its habits, being at all 
common. Next to this ranks Chr. ovulum, then Eulima Pdis- 
torta. What must be the richness of the ocean bed itself, if so 
many have left traces of their existence on the backs of a few 
oysters ! 

The generic distinctions in this family, as in Helicidre and 
Vcneridse, are confessedly of httle value. Links are found 
which unite all that have been yet proposed. When however 



MAZATLAN UNIVALVES 409 

species are so numerous and so difficult to identify, tlie grouping 
of similar forms and the separation of large assemblages is a 
great convenience to the student. Clark, whose researches 
among the animals of this tribe are most minute and valuable, 
regards the presence or absence of a columeUar plait as a 
variable character even in the same species : v. Moll. Test. 
Mar. Brit. pp. 395 — 154. The Mazatlan species appear con- 
stant in this character ; although the plait, when present, is 
often hidden, and cannot be seen except in broken shells, 
which thus assume a more than usual value. One of the best 
characters is found to be the shape and size of the sinistral 
portion : the first observations of it however must be taken 
with caution, as slight changes in the light or angle of observa- 
tion cause very different appearances under the microscope. 

Gen PS OBELISCUS, I[um:ph. 

Gray, Proc. Zool. Soc. 1847, p. 159.— -S". cj- A. Ad. Gen. vol. i. 
p. 229. 

P^'ramidella, p&rs, auct. — This group is intermediate between 
the typical Pyramidella; and Odostomia, differing from the 
former in its smooth surface and scarcely channeled mouth ; 
from the latter, in its numerous whirls and in the cokunellar 
plaits. Several species, very turrited but with a single lamel- 
liform plait, which are found recent in different seas, and also 
fossil, may be ranked with either genus. 

486. Obeliscus Pconicus, jun. C. B. Ad. 

Pyramidella conica, C. B. Ad. Pan. Shells, no. 294, pp. 200, 318. 
Obeliscus conicus, H. Sf A. Ad. Gen. i. 230. 
^ \ solitary young shell, with 5 normal whirls, agrees generally 
with the Panama species, especially in having the suture in 
a groove which travels round the periphery, and in having two 
very small plaits imder one which is large and lamelliforra. 
It differs in the base which is scarcely angulated, and in the 
divergence Avhich is gi'eater. Both these features may alter in 
the adult shell. The apex might appear "very acute" in an 
adult of 14 whirls, though it is rather obtuse in this specimen ; 
the nuclear whirls (one and a half) which are like a tumid 
Planorbis, being sunken in the normal portion, of which it 
covers about two>thirds. Long. 105, long. spir. 'OGo, lat. '055, 
div. 28». 

Nov. 1856. mm 



410 MAZATLAN UNIVALVES 

JTai.— Panama, 1 sp. C. B. Adams. — PMazatlan ; 1 young sp., 
off Chama ; L'pool Col. 

Tablet 1951 contains tlie specimen. 

Genus ODOSTOMIA, Flem. 

Edinh. Eneycl. 1817, p. 130. 

Jaminea, Broion. Couth. &c. 

Odontostomia, Phil, in Zeit.f. Mai. 1849, p. 28. 

Odontostoma, Phil. Handb. Cowc^. p. 192: non D'Orb. ; nee 

Odontostomus, Beck. 

For convenience' sake, the genus is here restricted to the 
smooth species ; the sculptured forms being located under 
Parthenia ; and the pupiforra species imder Chrysallida. All 
the divisions in this family must be regarded as provisional, 
till we know more of the forms from different seas. Some of 
the following species differ from the tjipical forms in having 
the peritreme continuous. 

Section A. Peritreme not continuous. 

487. Odostomia sublieulata, n. s. 

O. t. ovoided, suhohlongd, siibdiaphand, alba ; anfr. nucleosis 
declivibus, in truncaiione latiore celafis ; avfr. iv. ■normalibus, 
subrotundatis, suturis distinct is, basi elongatd, hand umbilicatd ; 
in spird, lavi ; infra peripheriam lirnlatd, lirulis svbobsoletis, 
rotundatis, interstitiis parvis ; aperturd ovatd, labro acuta ; 
peritremati circa basin usque ad parictem continuo ; labia in 
pariete nullo ; plied transversd, obtusiore, conspicud. 

One beautifully perfect specimen was found of this elegantly 
formed species, agreeing with the typical forms in not having 
any parietal lip. Lung. '078, long. spir. "038, lat. "012, div. 2S'*. 
Hab. — Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 

Tablet 1952 contains the specimen. 

488. Odostomia , sp. ind. 

Tablet 1953 contains a portion of a specimen larger than 
O. sublirulata, with the whirls plauate, and with very tme 
distant indented stride over the whole surface. 

^a6.— Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 



MAZATLAN TTNIVALVES 411 

489. Odostomia lamellata, n. s. 

O. t. conicd, turritd, soUdd, albd ; vertice nucleoso satis 
magno, declivi, maxim am partem tmncationis tegente ; anfr. 
normalihus subplanatis, lavihus, ad periplieriam angulatis, 
haud carinatis ; suturd parum impressd ; plica magna, extante, 
lamellosd, declivi. 

The description is compiled from portions, tlie only perfect 
specimen found having been broken under the microscope. 
This species, if it had secondary plaits, would rank with Obelis- 
CU8. It closely resembles O. canaliculata, C. S. Ad. Contr. 
Conch, no. 7, p. 109) from Jamaica ; but differs in being a 
wider shell, with the base more angidated. It probably had 
five normal whirls, and measured long. '1 + , lat. '04, div. 23". 
^aJ.— Mazatlan ; portions of 4 sp. off Chama ; L'pool Col. 

Tablet 1954 contains the young and old portions from which 
the complete idea may be constructed. 

490. Odostomia sttbstjlcata, n. s. 

O. t. " O. lamellatce" simili ; sed anfr. planatis, peripherid 
vix carinatd, plica obtusd, solidd, transversa ; vertice micleoso 
ut in " O. vallatd." 

Differs from O. mammillata and O. vallata in the solid texture 
of the shell, and strength of the plait. A yoimg shell, with 
three normal whirls, measures long. '044, long. spir. '024, 
lat. -028, div. 30". 
Sab.— Muzatlan ; 4 imperfect sp. off Chama ; L'pool Col. 

Tablet 1955 contains 2 specimens. 

Section B. Peritreme continuous. 

491. Odostomia vallata, n. s. 

O. t. conicd, parvd, subdiaphand, tenui, albd ; vertice nucleoso 
pariio, parum declivi, dimidium truncationis tegente; anfr. 
normalibus iii. et dimidio, planatis, suturd effbssd ; carinuld, 
super fossam, et spiram et peripheriam deciirrente ; perip/ierid 
acute angulatd, bust planatd, umbilico conspicuo ; aperturd 
coniinud ; plied obtusd, transversd, celatd, juxta parietem sitd. 

This beautiful little species, of a semi-transparent chalce- 
donic texture, is remarkable for its exactly conical form, well 



412 MAZATLAN TTNIVALVES 

marked umbilicus, continuous and very tkin peritreme, and for 
the vallum, consisting of a little ditch and mound ^at the 
suture, which are carried round the base. Long. "055, long, 
.spiv. -032, lat. -028, div. 30°. 

^a6.— Mazatlan ; 10 sp. off Chama and Spondylus ; L'pool Col. 

Tablet 1956 contains 3 sp., one youug, translucent, another 
adult, the third slightly distorted in growth. 



492. Odostomia mammillata, n. s. 

O.i. "0. vallatce" simili, sed angustiore ; vertice nucleoso 
siihtumcrde, anfr. prlmo normali roiimdato ; carinuld nulla ; 
?plicd celatd. 

The plait does not appear in the only specimen found. It is 
probable however, from its great resemblance to O, vallata, 
that it exists within. Long. "OiS, lo7ig. spir. "024, lat. "027, 
div. 22". 

jH«5.— Mazatlan ; 1 sp. off Chama ; L'pool Col. 
Tablet 1957 coatains the specimen. 



493. Odostomia tenuis, w. s. 

O. t. fenui, subconicd, alhd ; vertice nucleoso parvo, decliviter 
immerso ; anfr, iii. normalihns, suhplanatis, suturd impressd ; 
pe^npheria haitd angulatd, hasi rotundatd, umbilico conspicuo ; 
aperturd obovali, peritremati continuo, acuio ; lahro canali 
suturali a pariete disjuncto ; callositate parvd in labia columeU 
lari vix conspicuo. 

Like O. vallata in the thin continuous peritreme, umbilicus, 
and shght callosity ; differing from the neighbouring species 
in its rounded periphery and base, and in the sutural canal, 
which is formed by the separation of the last whirl, not the 
grooving of the parietal. Long. "OCi, long. spir. "OSS, lat. '028, 
div. 22". 
JTat.— Mazatlan ; 2 sp. off Spondylus ; L'pool Col. « 

Tablet 1958 contains the largest specimen. 



MAZATLAN UNIVALVES 413 

Subgenus ATJEICULINA, Gray. 

H. Sf A. Gen. vol. i. p. 233. 

In this ^oup are deposited some sliells, liaving the general 
aspect of Odostomise, but presenting no vestige of a plait, and 
with the vertex scarcely bent. They are not sufficiently well 
characterized for description. 

494. AuEicULiNA , sp. ind. (a.) 

Tablet 1959 contains 3 imperfect specimens, having the 
general aspect of O. gravida, Gould, (Cal. ^ Mex. Shells, p. 11, 
pi. 14, f. 14, Sta Barbara.) 
Mah. — Mazatlan ; extremely rare, off Spondylus and Chama ; 

L'pool Col. 

495. AuEicuLiNA , sp. ind. (b.) 

Tablet 1960 contains 2 imperfect specimens, white, differing 
from the last in being much narrower in i^roportion. 

Sab. — Mazatlan ; extremely rare, off Chama ; L'pool Col. 

496. Auric ULiNA , sp. ind. (c.) 

Tablet 1961 contains a fragment, like the last, but of a rich 
orange colour, with a conspicuously sinistral vertex. 
Hab. — Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 

Subgenus PARTHENIA, Loioe. 

Parthenia, JS. Sf A. Ad. Gen. i. 233. 
Parthenia (pars), Lowe. 

Shell with the surface somewhat strongly sculptured ; colu- 
mella plaited. 

Section A, Shell thin, turrited, transversely ribbed. 

497. Paethenia scalabifoemis, n. s. 

P. t. turritd, solutd, alba ; vertice nucleoso parvo, verticaliter 
sito, pcene immerso ; anfr. normalibus v. elongatis, postice 
acutius angulaiis, liris acutis, in adultd is., injuniore pluribus. 



411 MAZATLAN UNIVALVES 

transversis, valde extantihus, ad basin continuis ; interstitiis 
siibundulatis, Icevibus ; aperturA elongatd, peritremati con- 
finud, axi plica distinctd munitd. 

jSTuelear part very small and sunken ; next -n-liirl with 
numerous, fine, rather undulating ribs ; which gradually be- 
come less numerous, sti-aight, sharp, and very prominent. 
Whirls sharply angled at the shoulder, at rather less than 90*^. 
The lip is broken in both specimens, but it is distinctly con- 
tinuous. There is a general resemblance in form, (though the 
whirls are less numerous and longer) to Chemnitzia scalaris. 
Long. '1, long. spir. '065, lat. "37, div. 20". 
JIab. — Mazatlan ; 2 sp. off Chama ; L'pool Col. 

Tablet 1962 contains the finest specimen. 

498. Paethenia quistquecincta, n. s. 

P. t.formd "P. scalat'iformi" simtdante ; sed vertice nucleoso 
tumente, anfr. ii., verticaUter sitis ; anfractibus iii. et dimidio 
planatis, cequaliter transversim clathratis ; dathris acutis cir- 
citer xiii. ad suturam antice declivihus, postice muricatis ; 
suturis acute exaratis ; lirulis v. spiralibus cinctd, quorum una 
suturam continuat, altera supra partem declivem, tres in basi 
sitce sunt ; aperturd ovali, peritremati continud, plica parvd, 
declivi, intus celatd, hand umbiUcatd. 

The first normal whirl of this beautiful shell is marked like 
the rest. The ribs are more numerous than in P. scalariformis, 
from which it is at once distinguished by the 5 spiral threads, 
of which 3 appear on the base, one carries on the suture, and 
the fifth is above it, bounding the slanting portion of the 
whirls. Long. -063, long. spir. -038, lat. -025, div. 20°. 
Hab. — Mazatlan ; 2 sp. off Spondylus ; L'pool Col. 

Tablet 1963 contains the finest specimen. 

499. Paethenia lacunata, n. s. 

P. t. ovali, minimd, alba, tenui, subdiaphand ; vertice 
nucleoso marginibus spirce subexcurvatis nequaquam superante, 
decliviter sito, rotundato, vix tumente, apice celato ; anfr.iii. 
normalibus dathris «;'c;7er xviii. solidis tranversis obtusis, muni' 
tis ; periplieriam vci-siis a lacuna concavd, insculptd interruptis, 
circa basin ad umbilicum minimum tenue continuis; lacund 
carinis duabus spiralibus cinctd, quarum, una supra suturam, 
una ad suturam sitae sunt; interstitiis ad basin tenuissime 



MAZATLAN UNIVALVES 415 

spiraliter striatis, supra IcBvihus ; apei'tura ovali, peritremati 
vix continuo, plica suhdistinctd. 

Ttis species is known by tlie deeply cut channel above the 
suture, and the transverse bars continued on the other side of 
the channel in the form of fine lines running round to the 
minute umbilicus, with the interstices minutely spirally striated. 
The inner lip is seen best in dead specimens. The labrum is 
indented by the channel. The number of transverse ribs is 
variable. Long. '012, long. spir. '024, led. '023, div. 25". 
Hab. — Mazatlan ; 7 sp. off Spondylus ; L'pool Col. 

Tablet 1964 contains the largest specimen. 

Section B. Shell strong, short, spirally ribbed or nodulous. 
500. Paethenia aemata, n. s. 

P. t. ovato-conicd, solidd, albd ; veriice nucleoso planato sub- 
tumente, anfr. ii., suhprominente, verticaliter sito, marginibus 
spirce excurvatis vix superante ; anfr. v. normalibus, quarum 
prima lirulis transversis ef cingulo basali, alterce seriebus 
duabus spiralibus tulercularum, et carinis duabus acutis in- 
struct (B ; tuberculis maxime validis xv. — xx., serie superiore 
claviformibus, inferiore subquadratis, in adultd aperturam 
versus compressis, pane evanidis ; carina und majore in peri- 
pherid, altera in basin, parietem plicante ; plied columellari 
inferiori ; aperturd ovatd ; labro tenui ; suturis imp>ressis. 

This beautiful and highly sculptured species is somewhat 
analogous to O. gemmulosa, C. B. Ad. Co7it. Conch, no. 7, 
p. 109, from Jamaica ; from which it differs in the number and 
strength of the tuberculous ridges. The principal keel faUs 
into the suture of the succeeding whirl. The tubercles are not 
parallel, being more numerous in the lower row. In the con- 
traction of the lower whirl and thinness of the outer lip, it 
resembles Chrysallida. Long. "1, long. spir. "076, lat. "034, 
div. 28". 
Sa6.— Mazatlan ; 12 sp. off Chama and Spondylu.s ; L'pool Col. 

Tablet 1965 contains the most perfect specimen. 

501. Paethenia exaeata, n. s. 

P. t. conicd, validd, parvd, albd ; vei'tice nucleoso minuto, in 
parte truncatd celato ; marginibus spirce subrectis ; anfr. iv. 
profundississime exaratis, carinis iii. obtusiorihus, validissimis 



416 MAZATLAN UNIVALVES 

ornatd, qiianim prima ultimam anfractus superioris tegit ; 
carina quarto, in basin angulatam sitd ; aperiur& ovali ; lahro 
solido ; plied parvd, celatd. 

Tkis stout little skell is at once recognized by its strong 
keels, of which two appear on the penultimate whirl, the third 
being covered by the first of the ultimate. Long. •252, long, 
spir. -03, lat. -032, div. 35". 
Hab. — Mazatlan ; 2 sp. off Chama ; U'pool Col. 

Tablet 1966 contains the largest specimen. 



502. Paethexia ziziphixa, n. s. 

P. t. conicd, albd ; vertice nucleoso mammillato ; anfr. liris 
rotundatis v. spiralibiis, quaviun una major ad peripheriam, 
duce tn sspird, duw in basi angulatd sitce sunt ; plied transversd. 

Tablet 1967 contains a small Ziziphinus-shaped shell, very 
young, differing from P. exarata in the number and strength 
of the spiral ridges. Long. '026, lat. '022. 

Sab. — !Mazatlan ; 1 sp. on Chama ; L'pool Col. 



Subgenus CHEYSALLIDA. 

Testa utrinque constrieta, pupiformis ; peritrema continuum, 
ad basin undatuni ; labruni juxta aperturam tenue, intus soli- 
dius ; plica eolumeUaris declivis, scepe celata ; superficies ple- 
rumque cancellata. Operculum \_sp. ti/p.'\ radiatim corrugatum. 

Chemnitzia, pars, C. B. Adams, (Pan. Shells, no. ?220, ?222, 

223, 226.) 

The typical species differ from Chemnitzia in having a dis- 
tinct, though hidden plait ; from Odostomia proper in having 
the peritreme continuous ; from ^lonoptj'gma in the Pupiform 
growth, contracted at each end ; and from all in the labrum, 
which is extrcraelj- thin at the edge, in the adult as well as in 
the young shell ; while within, as she'wn by broken specimens, 
it is tolerably strong. That the sectional limits are not exactly 
defined, is true of almost every groi;p in this family. Similar 
forms occ\ir both in the E. and W, Indies. The ^lazatlan 
shells are represented by 15 species, of which about 650 speci- 
mens were found. The specific characters often depend on 
very minute differences. 



MAZITLAN TJNIVAIVES 417 

Section A. Species Odostomoidece. 
503. Cheysallida ovata, n. s. 

Chr. t. Jiaud parva, solidd, ovata, alha ; vertice nucleoso 
parvo, omnino celato ; marginihus spirce paruvi excurvatis ; 
anfr., pauciorihus quoad magnitudinem,'rv. et dimidio, suhro- 
iujidafis ; sutura impressa ; liris tiiherculosis transvei^sis, testa 
junio?-e snbdistantibus, testa aduUd contiguis, marginihus spirce 
vix parallelis ; lirulis spiralihus, in spird iv. vix monstraniibus, 
circa peripheriam et hasiji rotundatas vi. validis, rotundatis, 
interstitiis parvis rugoso-decussatis ; apei'turd parum contractd, 
peritremati continuo, labio interdum rimulam umlilicalem 
7nonstrante ; plied solidd, ohtusd, parum celatd. 

This species and the next are at the confines of the group, 
Tvith which they agree in general habit, sculpture, and con- 
tinuous peritreme, while the form is that of the typical Odos- 
tomia^. The pattern closel.y resembles that of Chr. nodosa, 
and the apex that of Chr. fasciata, from both of which it differs 
in its broad expanding form, the adolescent shcUs being like 
the adults. The lip is not thin, but agrees with the group in 
being much more solid within, as is shewn by the broken 
shells, of which there were several, though xery few of any age 
were perfect. The largest (a monster for the gi'oup) measures 
long. -155, long. spir. '08, lat. "OSS, div. 35", 
Mab. — Mazatlan ; very rare, off Spoudjdus ; L'pool Col. 

Tablet 1968 contains the youngest, the oldest, and an inter- 
mediate specimen. 

501. Cheysallida nodosa, n. s. 

Chr. t. subconicd, solidd, alba ; vertice nucleoso minimo, 
prominente, marginibus spirce vix excurvatis parum superante ; 
anfr. jiormalibus v. latis, subplanatis ; lirulis spiralihus iv. 
transversis usciue ad xvii. sibi parallelis, ad intersectiones nodosis; 
tuherculis rotundatis, validis, tran-sversim attingentibus, spirali- 
ier plerumque separatis ; lirulis transversis supra suturam 
impressam declivibus ; lirulis spiralihus in basi rotundatd 
\\. rotundatis, interstitiis tenue decussatis ; plied cohunellari 
parum celatd, validd, obtusd ; aperturd (in t. adultd) oblongd, 
parum contractd, ad basin productd, peritremati continuo, labio 
haud tenui. 



418 MAZATLAN UNITAIVES 

Of tliis broad and strongly built species, three young shells, 
one adolescent and one adult were found. It is known at once 
from Chr. ovata by the prominent little vertex at the head of 
the pointed spire. The first whirls are very spreading. The 
base is angulated in the adolescent shell, but rounded in the 
adult. The base of the columella is produced in all stages, 
almost notched when young. The labrum is extremely thick 
in the broken shell. The sutural groove is formed as in Chr. 
telescopium, but the sctdpture most resembles that of Chr. 
ovata. A young specimen with two and a half normal whirls 
measures long. "OIG, long. spir. "022, lat. "034, div. 50°. 

The adult sp. „ -163, „ -098, „ -072, „ 30". 

Sab. — Mazatlan ; 5 sp. off Spondylus ; L'pool Col. 
Tablet 1969 contains the adult and a young specimen. 

505. Chrysallida kotundata, n. s. 

Chr. t. tenuiore, ovatd, solida; vertice nucleoso parvo, planato, 
veriicaliter in medio sites, prominente, marqinibi(S spirce excur- 
vatis pantm superanie ; anfr. iv. normaUhus, tumentihus, 
suturis conspicuis liris xi. spiralihus, solidis, rotundatis, con- 
tiguis, quarum v. in spirit sita sunt ; interdum, maxime in testd 
juniore, transversim tuberculosis ; interstitiis tenue decussatis ; 
basi rotundatd; apertura parum contracts, p>entrematt continue, 
labio tenui, plied obiusd, vix celatd. 

Of the shape of Chr. ovata, but even more like the normal 
Odostomia) ; Avith a very different vertex ; and separated from 
all the other species by the transverse markings being almost 
obsolete. They appear however here and there, as though to 
shew the bond of relation. In this species also the young 
follows the type of the adult. . !Nine complete shells and a few 
fragments were found. Long. "09, long, spir, '048, lat. "045, 
div. 35°. 
Hab. — Mazatlan ; very rare, off Spondylus ; L'pool Col. 

Tablet 1970 contains the youngest, the largest and an inter- 
mediate specimen. 

506. Chbysallida oblonga, n. s. 

Chr. testd ovato-oblongd, tenuiore, albd ; vertice nucleoso ut 
in " Chr. rotundatd ; " anfr. V. normalibus, subconvexis, suturd 
diMinctd; liris X. in spird spiralibus, rotundatis, interstitiis 



MAZATLAN tTNIVAlVES 419 

minimis, quarum una suprasuturalis simplex, et iv. tuberculoses, 
tuberculis rotundatis, lineis transversis sibi parallelis sitis, in 
anfr. penult, circiter xx., in t. adiilta evanidis ; lirulis in basin 
rotundatam circiter vii., t.juniore acutioribu-s, interstitiis tenuis- 
sime et creberrime decussatis ; apertura ovatd, peritremati vix 
continud ; labro acuto, vix planato, supra suturam- producto, ad 
basin vix simiato ; labio in parietem tenuissimo, infra distincto, 
rimulamumbiUcalemformante; plied intus acuta, extu^obtusd, 
hand conspieud. 

This fine species approaches Monoptyanna. It differs from 
Chr. rotundata in the tuberculation of the spiral ribs and the 
much greater prolongation of the shell. The basal striae seem 
to become broader in the adult, as the tuberculation of the 
upper ribs vanishes. The young shells are slender, with 
rounded bases. The tubercles are arranged in the form of 
transverse ribs, parallel to each other, and running in slanting 
lines to the apex. Long. '1.53, long. spir. '095, lat. "067, 
div. 22«. 
Sab. — Mazatlan ; 4 sp. and fragment, off" Spondylus ; I! pool 

Col. 

Tablet 1971 contains the largest sp. presented by E. D. Dar- 
bishire, Esq. and a very young shell which may belong to this 
species. 

Section B. Species typiccz. 

507. Chbysallida communis, C. B. Ad. 

Chemnitzia communis, C. B. Ad. Pan. Shells, no. 223, pp. 166, 

312. 

Chr. t. ovato-oblongd, gibbosd, soUdiore, nitente, alba ; vertice 
nucleoso parvo, spircc truticationem dlmidio tegenie, anfr. ii. 
verticaliter sitis, ajnce vix celato ; marginibus spirce maxime 
excurvatis ; anfr. normaUbus iv. — vi, planatis, suturdprofundd; 
clathris transversis, utrinque margiriibus spirce parallelis, testa 
juniorc conspiciiis, aperturam versus evanescentibus, juxta 
peripheriam terminantibus, anfr. penult, circiter xxii. ; lirit 
spiralibus iv. vel v. suprasuturalibus, arfr. primis minoribus, 
anfr. ultimis sape clathras in iubercu/a secantibus ; lirulis 
rotundatis vix expressis circiter x. supra basin ovatam inter- 
stitiis punctulis decussatis ; sculpturd in labro tenuissimo, dia- 
phano evanescente ; labro antice late sinuato, postice planato 
angustato, ad suturam constricto, labio scepe a pariete separata ; 



420 MAZATLAN UNIVALVES 

plied decUvi intus conspicuo extus ad labrum sinuatum eircum- 
eunte ; operculo tenmssimo, vix spirali, striulis rugosis radian,' 
tibus ornato. 

As no fewer tlian 500 specimens were found of this typical 
species, (a rare number for a P^Tamidellid.) most of them in 
very fresh condition, it is possible to describe it with tolerable 
accuracy. It is distinguished from its neighbours by the basal 
strise which are numerous, close and fine, beautifully adorned 
between with dots more or less elongated. The outer lip is 
produced and broadly indented at the base, narrow above and 
pinched at the suture, where it joins the labium which is 
often rather separate from the body whirl. The plait winds 
round the axis and develops into the boundary of the basal 
sinus. The sutural groove is not carried over the base, but is 
formed simply by the transverse ribs ending just before they 
reach the next whirl. These are not parallel to each other, 
but to the diverging outlines of the spire. They are very 
conspicuous on the young shell, which is broad and rather 
angiilated at the periphery. As the adult shell narrows itself 
in, the base is produced and rounded, the ribs become some- 
what indented by the spiral hues, and near the mouth fade 
away altogether. In the adolescent state the labrum is often 
beautifully serrated hj the spiral stria; ; in the adult the lip is 
still transparent in the living shell. Its great thinness causes 
it to be frequently broken and repaired, the fresli part being 
not unfrequently almost devoid of sculpture. The spire is 
sometimes encrusted with coralline during the life of the animal. 
The operculum, (traces of which were observed in only about 
a dozen specimens,) is large, extremely thin, transparent, 
sometimes shewing a slightly spiral element, and covered over 
almost the whole surface with most minute wrinkles, radiating 
incurves from the centre like the engine-turning of a watch. 
Not only the size, but the number of whirls varies in different 
specimens known to be adidt by the shape and evanescence of 
the sculpture, ^'^ery few are so large as those from Panama, 
and they generally make one turn less. The smallest specimen 
measures "03 by "021 ; the smallest adidt, '053 by '025 ; an 
unusually large one, long. '12, long. spir. '085, lat. (m med.) 
•048, div. 23". 
Hah. — Panama ; 90 sp. under stones near low water mark ; 

C. B. Adams. — Mazatlan ; abundant and fresh among algse 

on UvanUla, somewhat rare on Chama, Spondylus, &c. ; 

L'pool &f Savre Coll. 



MAZATLAN TTNIVALVES 421 

Tablet 1972 contains 9 sp. very young.— 1973, 8 do. adoles- 
cent.— 1974, 9 do. adult, various sizes.— 1975, 3 do. repaired 
after fracture.— 1976, 2 sp. witk opercula.— 1977, 1 sp. beauti- 
fully encrusted, auotber with broken lip shewing the fold 
within, and 2 dead sp. in which state the details of sculpture 
are conspicuously marked. 

508. Chetsallida telescopium, n. s. 

Chr. t. conicd, turritd, alha ; vertice nucleoso, satis promin- 
ente, anfr. ii. helicoideos verticaliter sitos conthienie, apiceparum 
monstrante, marginihus spircB (testa adolescente) rectis vix 
superante ; anfr. vii. normalihus, quarum v. planati, in spird, 
ut in " Chr. communi," clathris circiter xvi. et liruUs spiralibus 
iv. decussatis : testa adolescente, lacuna suturali impressd circa 
basin continud ; peripJierid angulaia, aperturd subquadratd ; 
testa adtiltd, basi hand angulatd, effusd, liaud lacunatd ; peri- 
tremati continuo, ad basin late sinuato : basi lirulis spiralibus 
circiter \n. cinctd, interslitiis vix decussatis ; plied columellari 
intus acuta, prominente, ad aperturam vix monstrante, declivi. 

This species begins life as a helicoid body, rather large in 
proportion as in Chemnitzia, which genus it also approaches in 
the number of whirls. These are flat, with straight margins, 
having the basal peripliery angiUated in the adolescent sheD, 
in which state it approaches the form of Telescopium. The 
sutural groove, formed by the hollowing off of the ribs in the 
last cancellated division, is then continued round the base. In 
the last whirl however, the shell is contracted, the base pro- 
duced, the sutural groove evanescent, the aperture effuse, and 
a strong continuous labium finally appears. It is known from 
Chr. communis by the large size of the vertex, taking off the 
appearance of truncation from the shell ; iu the nou-adult state 
by the greater angidation of the base and antesutural groove 
(the ribs in the common species not quite reaching the suture) ; 
and in all states by the greater divergence, and by the basal 
strife, which are stronger and less numerous. A specimen in 
the angular state measures long. '082, long.spir. "055, lat. '037, 
dio. 30°. One almost adult measures long. "125, long. spir. '085. 
Hab. — Mazatlan ; 10 specimens (mostly young) off Chama and 

Spondjlus ; L'pool Col. : — do. 3 sp. (one adult) ; Havre Col. 

Tablet 1978 contains the youngest sp., with two and a half 
normal whirls ; an angular specimen witli 5 whii-ls ; a perfect 
sp. with 6 whirls, normal form, but without the parietal lip ; 
Dec. 1856. nn. 



422 MAZATLAN TTNITALVES 

and a broken adult sp. shewing the lip. This, when perfect, 
must have had 7 normal whirls. [One of Mr. Hanley's speci- 
mens, though small, has the peritreme continuously developed, 
and shaped as in Chr. communis.] 

509. Cheysallida Eeigeni, n. s. 

Chr. t. forma et sculptura " Chr. telescapio" simiilante, sed 
hasi rotutidatd, vertice nucleoso ut in " Chr.fasctatd" celato. 

One specimen only, somewhat broken and immature, was 
found of this species, which is named in remembrance of 
the gentleman to whose almost unparalleled zeal we owe the 
immense collection, a very small part of which is here described. 
A minute iimbilical chink is seen, probably from a fracture of 
the labium over one of the basal striae. Lang. '0^7, long. spir. 
•034, lat. -028, div. 26°. 
Sab. — Mazatlan ; 1 sp. off Spondylus : L'pool Col. 

Tablet 1979 contains the specimen. 

510. Cheysallida effusa, n. s. 

Chr. t. ovoided, alhidd, effusd ; marginihus spirce excurvaUs ; 
vertice nucleoso ?... ; anfr. ?\\. parum planatis, lirulis spiralihus 
acutis viii. cinctd, quarum iv. in spird, a lirulis fi'ansversis, sibi 
parallelis, in lineis declivibus ad i^erticem, ascendentibus, acutior- 
ibus, decussatcB, ad intersectiones nodosce ; una extans suturam 
coniinuat ; altera; in basin valde product am ; striulis iii. ad 
regionem umbilicalem ; lirulis transversis juxta suturam im- 
pressam declivibus, evanescentibus ; interstitiis basalibus latis 
distanter tenuissime decussatis ; labro ad basin valde sinuato, 
effuso ; plied celatd, parvd, acuta. 

Of this species, the most delicately sculptured in the group, 
only one not quite matiu'e specimen was found, the vertex of 
which is imfortunately injured. The transverse riblets are 
parallel to each other, not to the margins of the whirls, and 
vary in number accordingly. The structure of the sutural 
groove is as in Chr. telescopiiim. Long. '09, long. spir. '054h. 
lat. -038, div. 20". 
Hab. — Mazatlan ; 1 sp. off Chama ; L'pool Col. 

Tablet 1080 contains the specimen ; also a very young shell, 
with a sunken apex, which might have developed into this 
species or into a slender form of Chi-, fasciata. 



MAZATLAN XJKIVALVES 423 

511. Cheysallida fasciata, n. s. 

Clir. t. ijarva, ovoided, alba ; vertice nucleoso parvo, declivi, 
omnino celato ; marginihus spirce excurvatis ; anfr. normalihus 
iv. — v., clathris circitej' xviii. tuherculosis, lirulis iii. plus 
minusve conspicuis, decussantihus, cingulo quoque super suturam 
extante, interstitiis utrinque tenue decussatis, ornata ; basi 
rotundatd lirulis circiter iv. spiralibus suhacutis cinctd, inter- 
stitiis latis, lineis clathra continuantibus terme decussatis ; plied 
columellari celatd, 'parvd, obtusd ; peritremati vix continuo, 
labio tenui. 

This species has some characters in common ^dth Chr. mar- 
ginata, C. B. Ad. (Pan. Shells, no. 226) from which the number 
of ribs at once distinj^uishes it. In manj' respects it resembles 
Chr. OYiiIiim, from which it differs in its breadth and larger size, 
in the prominence of the suprasutiiral baud, the fineness of the 
few basal strise, and the sunken position of the nuclear whirls 
on the broadly truncated ("01 across) spire. Some of the 
specimens are short and broad in proportion, which is the 
character of the earlier stage generally. A young shell, with 
two and a half normal turns, measvires long. '036, long. spir. 
•017, lat. '027, div. 30°. The largest, unusually elongate, yet 
not quite mature, Zo«</. "083, long. spir. '0^, lat. '042, div. 22^. 

Sab. — Mazatlan ; 20 sp. off Spondylus ; L'pool Col. 

Tablet 1981 contains 5 specimens ; two very j'oung, one 
dwarf, one mature, broad, and one almost mature, elongated. 

512. Cheysallida ovuLrii, n. s. 

Chr. t. minimd, gibbosd, alba, soUdiore ; vertice nucleoso 
"Chr. communi" simulante, marainibus spirce valde excurvatis, 
haud superante ; anfr. nonnalibus iii. et dimidio, interdum 
clathruUs transversis circiter xviii., interdum lirulis spiralibus 
iv. nodulosis superantibus ; lacuna suturali profunda, in basin 
rotundatam, effusam, haud continud ; aperturd conq^actd, labro 
parum tenui, intus soUdo ; plica columellari obtuso ; lirulis 
rotundatis in basin spiralibus circiter vi., interstitiis minimis, 
vix decussatis. 

About 70 specimens of this stumpy little species were found, 
differing from the dwarf forms of Chr. communis in the strength 
of the spiral riblets, which generally break the transverse 
bars into coarse tubercles, and in the small number and promi- 
nence of the rounded basal strisD. The whirls are very few. 



424 MAZATLAN TJNIVALVES 

sometimes not more tlian two and a half in tlie adult. A 
? variety has the sculpture much finer. A large sp. measures 
long. -055, long. spir. -032, lat. '027, div. 25". 
Sah. — Mazatlan ; not common, ofi" Spondylus and Chama ; 
L^pool Col. 

Tablet 1982 contains 9 specimens in different stages. 



Section C. Species Chemnitziformes. 

513. Cheysallida clathbatula, C. B. Ad. 

Chemnitzia clathratula, C. B. Ad. Pan. Shells, p. 165, 311, 
no. 222. 

This species passes into the rounded cancellated forms of 
Chemnitzia, (Subgenus Dunkeria,) from which it is known by 
the distinct fold on the columella, and continuous peritreme. 
The last whirl is but slightly contracted. It is known at 
once from the rest of the Chrysallida} by its very elongated 
form and rounded whu4s. The solitary jNIazatlan specimen has 
lost its upper portion ; but the imperfection of the aperture 
brings to light the obHque distinct columeUar plait, which 
escaped the notice of Pi-of. Adams. 
JSah. — Panama; 10 sp. in sand; C. B. Adams. — Mazatlan; 

1 sp. off Chama; L'pool Col. 

Tablet 1983 contains the specimen. 

514. Chetsallida contexa, n. s. 

Chr. t. gracili, tereti, fenui, alhida ; verflce nucleoso anfr. ii. 
helicoidalihus, magnis, declivibus, marginihus spirce, parum 
excurvatis, superantibus, quarum apex in anfr. nonnali p))'inid 
horizontaliterjacet, parum prominens ; anfr. normalihus v. valde 
convexis, liris ohtusis circiter xiv. radiantibus, ad suturam pro- 
fundam scepius affingentibus, circa basin cvanescentihus ; lirulis 
spiralibus in partem anteriorem anfrnctuum, interstitia tenue 
decussantibus, quarum iii. in spirit videntur, circa basin satis 
rotundatam plures ; aperturd subovali, parum contraetd ; 
rolumelld oblique plicatd ; labia ienui. 

Tb is remarkable shell has the apex and growth of a Chem- 
nitzia, the convex whirls of Aclis, with the spiral plait and 
(slightly contracted) aperture of Chrysallida. The lower half 



MAZATLAN UNIVALVES 425 

only of the whirls is spirally sculptured. Long. "081, long. spir. 
■061, lat. -025, div. 14". 

Hab.—Mazailav. ; 2 sp. off Spondylus ; L'pool Col. 

Tablet 1984 contains the largest specimen. A hole behind 
displays the plait. 



515. Cheysallida Photis, n. s. 

Chr. t. alhidd, gracili, solute spirali ; vertice nucleoso ut in 
" Chr. convexa" sito, sed mulfum minore, marginibus spircB 
valde excurvatis haud superante ; anfr. normalibus iv. valde 
convexis, ut in " Phote" cancellatis, liris tvansversis nodosis xii. 
ad suturas valde impressas attingentibus, decliviter ad verticem 
ascendeiitibus, ad basin continuis ; lirulis spiralibus supra liras 
nodosis, inter eas eleganter undulatis, quarum iy. in anfr. penult, 
apparent ; anfr. ult. contracto ; ajierturd continua, ovali, postice 
contractd ; j)liod obliqud, celatd. 

This very elegant little shell is sculptured as in Phos, with 
the tumid whirls of Aclis, the apex of Chemnitzia, and the 
aperture of Chrysallida. The plait is scarcely seen in the 
perfect shell, but conspicuous in the broken one. long. '049, 
long. spir. '032, lat. '019, div. 12". 

Hal. — Mazatlan ; 2 sp. off Spondylus ; L'pool Col. 

Tablet 1985 contains the perfect specimen. 

516. Chrysallida indentata, n. s. 

Chr. t. obtusiore, albd, subconicd ; vertice nucleoso helicoideo, 
satis magno, marginibus spirce reetis vix superante, haudpro- 
minente, anfr. ii. globosis, subverticaliter sitis, apice conspicuo ; 
anfr. normalibus subconvexis, ad suturam impressam a liris sub- 
muricatis ; liris acutis, subrectis, circifer xviii. itfra suturam 
subindentatis ; testa juniore ad periphcriam pcene evanidis, 
lineis circa basin vix conspicuis ; striis spiralibus, in spird 
circiter v. interstitia decussantibus, eleganter undulatis ; circa 
basin striis crebrioribus, inter lineas transversa.'i undulatis ; 
t. adultd, liris circa basin continuis, sculpturd spirali superan- 
tibus ; aperturd pyriformi, continua, postice contractd ; labro 
ad basin vix effuso ; labia separato ; columella haud contorid ; 
? plied celatd. 



426 MAZATLAN UNIVALVES 

Tlie completion of the peritreme, and absence of the twisted 
columella distinguish this species from Chemnitzia ; but no 
plait can be discerned either in the yoxing or old specimen 
which are both quite perfect. A broken specimen would 
probably display it. The species is characterized by the sharp 
ribs, indented at the suture, with the interspaces elegantly 
decussated with curved lines. The young shell, with 4 normal 
whirls, measiires loyig. "062, long. spir. '037, lat. '032, div. 30°. 
Adult, with 7 whu-ls „ '153, „ -113, „ -05, „ 18«. 
-H"rt5.— Mazatlan ; 2 sp. off Spondylus ; L'pool Col. 

Tablet 1986 contains the adult specimen. 

517. PPCheysallida clausilifoemis, n. s. 

?? CJir. t. valde elongatd, efficsd, spird " Clausilice" dextrce 
simulante ; vertice nucleoso helicoideo, avfractihus ii. et dimi- 
dio, 2^rominente, veHicaUter sito, ah avfractihus normalihus 
separato ; marginihvs spirce valde excurvatis ; anfr. normalibtis 
duohus primis valde tumentihus, vix attingentihus ; dein anfr. v. 
suhplanatis, suturis expressis, fascia hipartitd, interdum 
suhnodulosd ; liridis ohsoletis transversis, et striis spiralibtis 
circa hasin effusam indistincie 07'natd ; totd superficie minutis- 
sime transversim rugiilosa ; aperturd ohlongd, ad hasin valde 
effusd ; j^licd ohliqiid, sithacutd ; operciilo paticispii'ali, tenuis- 
simo, rugulis ciirvatiin radiantihus insinicfo. 

This most aberrant species is placed here from some of its 
characters ; others are so pecviliar to itself as almost to justify 
its sectional separation. Its form is that of a dextral Clausilia, 
with the apex of a very acute Chemnitzia, the nearly smooth 
surface of Eidimella, and the fold, the opercidum, and the 
constricted mouth of ChrysalHda. The peculiarities are the 
separation and tumidity of the first two normal whirls, and the 
structure of the suture. This, instead of being impressed, has 
a slight raised deposit in each whii'l, which meets its neighbour 
like the runs of two i)lates. AM the four specimens found were 
imperfect and disintegrating ; in one of them however the 
operculum, as well as the vertex, were preserved. The largest 
must have measured when perfect, long. "15, long. spir. '095, 
lat. -aiS, div. 20". 
Sab. — Mazatlan ; 4 sp. off Chama ; L'jjool Col. 

Tablet 1987 contains the least imperfect specimen, with its 
operculum. 



MAZATLAN tTNIVAlVES 427 

GENtrs CHEMNITZIA, B'Orh, 

Nat. Hist. Canar. 1839.— J?brJes ^ Hani. Br. Moll. vol. iii. 

p. .— Woodw. Man. Moll. Tp. 126. 
Turbonilla, Bisso, Nat. Sist. Eur. Mer. vol. iv. p. 224, 1826.— 

Phil. Handh. Conch, p. 193.—^. Sf A. Ad. Gen. vol. i. p. 230. 
Parthenia, Lotve, Ann. Mag. Nat. Sist. vol. vi. p. 511, 1841. 
Pyrgiscus, Phil. Arch.f. Nat. vol. i. p. 50, 1841. 
Pjramis + Jaminea, Brown, Brit. Conch. 
Amoiu-a, Miill. 
Orthostelis, Arad. Sf Magg. Cat. Reg. p. 189, ? 1844. 

Species typicjs. Anfractibus planatis. 

Section A. Without spiral sculpture, 
(a.) Bibs interrupted at the periphery. 

518. Chemnitzia ? Panamensis, C. B. Ad. 

Pan. Shells, no. 227, pp. 168, 312. 

Tablet 1989 contains a dead specimen which appears suf- 
ficiently like the tyi^e in Mr. Cuming's Collection. It has 5 
whirls, the apex being deficient both in this and in the type. 
The species is rather broad, with very flat whirls, stout, rather 
slanting ribs, and very deeply cut grooves as far as the peri- 
phery. It measures long. "075, lat. '025. 
Sah. — Panama ; 11 sp. in the sand on the reef, between high 

water and half tide levels ; C.B.Adams. — PMazatlan; 1 sp. 

off Chama ; L'pool Col. 

519. Chemnitzia C-B-Adamsii, n. s. 

Ch. f. gracili, alba, elongatd ; vertice nucleoso anfr. iii. 
prominentibus, declivi, marginibus spires rectis superante ; 
anfr. ii. prope apicem rotundatis ; deinde yH. planatis, suturd 
impressd ; liris circiter xviii. rectis, solidis, obtiisis, ad peri- 
pheriam suhito obsoletis ; basi subrotimdatd ; labro tenui ; 
cohimelld tenui, vix intortd. 

Shell intermediate between Ch. aculcus and Ch. Panamensis, 
with all the whirls except those next the apex flattened. The 
apex is very large, with 3 tumid whirls, set rather slanting on 
the axis. It is named in remembrance of Prof. Adams of 
Amherst, U. S. whose early death has deprived science of one 



<12S MAZATLAN UNIVALVES 

of her most accurate and careful labourers. Long, '15, long, 
iplr. -125, lat. -036, div. 11". 

i/a6.— Mazatlan ; 12 sp. off Chama & Spondylus ; L'pool Col. 
Tablet 1990 contains tke finest specimen. 

520. Chemnitzia Psimiiis, C. B. Ad. 

ran. Shells, no. 228, pp. 168, 312. 

There being no type of this species in Mr. Cuming's collec- 
tion, it is determined with doubt. It is described as differing 
fiom Ch. Panamcnsis in being shorter, -with the whirls rather 
i.nore convex, and the periphery rounder. The apes has 3 
tiirns, and projects beyond the margins of the spire. The 
J irgest specimen, which has nine whirls, and is beautifully 
Iranshicent, measures long. "072, led. '028, div. 20". 
jT«5.— Panama ; 2 sp. in the sand ; C. B. Adams.— ^ Mazatlan ; 

6 young sp. off Chama and Spondylus ; L'pool Col. 

Tablet 1991 contains the finest specimen. 

521. Chemnitzia aculetjs, C. B. Ad. 

Pan. Shells, no. 219, pp. 164, 311. 

Shell extremely slender, but with the upper whirls not 
nearly so pointed as in C. gracillima. The apex in Mr. Cum- 
ing's tyi't* specimen has 3 turns and slightly projects beyond 
the line of tlie whirls. These are scarcely convex, with 14—17 
stout ribs formed by the scooping out of smooth interstices 
which end on the periphery. The largest specimen, with ten 
whirls, measures long. '13, long. spir. '108, lat. '03, div. 12". 
J3a6.— Panama ; 4 sp. in sand ; C. B. ^(/a»i5.— Mazatlan ; 

6 do. off Chama and Spondylus, dead ; L'pool Col. 

Tablet 1992 contains the least worn of the specimens. 

522. Chemnitzia mubicata, n. s. 

Ch. t. satis gracili, alhd, suhdiax>hand ; vertice nucleoso anfr. 
iii., rotundatis, marginihus sjrirce rectis vix superante, tiimente ; 
anfr. normalihus vii. angicstis, planatis, clathratis ; liris cir- 
citcr xvii. solidis, rectis, vix declivibus, plericmqiie lineis ad 
apicem decurrentihus ; suturd impressd ; liris ad suturam 
prominentibus, inuricatis ; interstitiis usque ad penpkeriam 



MAZATLAN TTNIVALTES 429 

profunde excavatis ; basi IcBvi, rotunclata ; labro tenui ; colu- 
mella eleganter infiexa. 

This beautiful little species closely resembles Ch. turrita, 
C. B. Ad. Pan Shells, no. 230, pp. 169, 312 ; from wliicb it 
differs in tlie entire absence of spiral keels at tbe base. The 
apical whirls are extremely tumid ; the rest are all flat, com- 
pact, and somewhat muricated at the sutures by the projecting 
ribs. Long. '09, long. spir. '07, lat. "027, div. 13". 
^ffi.— Mazatlan ; 5 sp. off Spondylus ; L'pool Col. 

Tablet 1993 contains 2 sp. differing in texture, and in the 
position of the apex, but probably eonspecific. 

(b.J Bibs more or less continuous over the base. 

523. Chemnitzia Paffinis, C. B. Ad. 

Pan. Shells, no. 221, pp. 165, 311. 

Although this species is described as "very smooth_ ante- 
riorly," the type specimen in Mr. Cuming's collection is 
distinctly striated spirally round the base, over which there is 
a very faint indication of the ribs: apex scarcely projecting, 
of two whirls. The Mazatlan specimen is rubbed ; it has 
seven whirls and measures long. "068, lat. '03, div. 20 . 
Brti.— Panama ; 2 sp. in the sand ; C. B. ^t^ams.—? Mazatlan ; 

1 sp. off Chama ; L'pool Col. 

Tablet 1994 contains the specimen. 

524. Chemnitzia peolongata, n. s. 

Ch. t. elongatd, gracili, tereti, albidd ; vertice nucleoso anfr. ii. 
helicoideis, marginibus spiral suhrectis haud superante ; anfr. 
normalibus xi. subconvexis, suturis impressis ; costis subacutis 
circiter xxii., hand continuis, vix decUvibus, ad basin tenue 
prolongatis, ad rimulam umbilicalem ascendentibus ; aper- 
turd ovatd ; labro acuto ; colutnelld eleganter intortd. 

This gracefid species, a little group of which was discovered 
in a cavity on Spondylus by Mr. Darbishire, is distinguished 
from similar West coast species by the faint prolongation of 
the rather slender ribs over the base to the umbilical chuik 
formed by the slight twisting of the columella. The nuclear 
vertex is not broader than the next whirl. An adult specimen 
measures long. "215, long. spir. "175, laf. "05, div. 13". 



430 MAZATLAN TJNIVALTES 

Hab. — Mazatlan ; extremely rare, off Spondylus ; L'pool Col. 
Tablet 1995 contains a specimen presented by E. D. Dar- 
bishire, Esq. 

(c.) Gibbous and uncertain species. 

525. Chemnitzia gibbosa, n. s. 

Ch. t. pupiformi, rufo-fusca, spirce marcfinihus utrinque ex- 
curvatis ; verfice nucleoso ?... ; anfr. normalibus x., planatis ; 
liris transversis subexpressis, subrotundatis, 7'ectis, circiter xviii. 
ad apicem continuis ; labro ? 

This species is described, although from a solitary and verj' 
imperfect specimen, in consequence of its great peculiarity of 
form, in which, it resembles Chrysallida. It is short, stumpy, 
and very broad ; without any trace of fold on the columella or 
notch on the base. Long. "2!7, lat. "1, div. 25". 

JIab. — Mazatlan ; off Chama, extremely rare ; L'pool Col. 

Tablet 1996 contains all that was found, viz. the broken 
specimen, and a fresh fragment displaying sculpture. 

526. Chemnitzia , sp. ind. (a.) 

Tablet 1997 contains the spire of a very stout shell, with 
about 12 very stout ribs on each whirl, running in continuous 
diagonal lines to the apex. There is no trace of columellar 
plait. 
Sab. — Mazatlan : 2 sp. off Spondylus ; L'pool Col. 

527. Chemnitzia , sp. ind. (h.) 

Tablet 1998 contains the spire of a Eulimoid shell, of alabas- 
trine textui'c, mth about 20 extremely faint ribs, running in 
diagonal lines to the apex. It is not so broad as the last species. 

Sab. — Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 

528. Chemnitzia , sp. ind. (c.) 

Tablet 1999 contains a very small specimen of a large species, 
too young to identify, as it has only one normal whirl and a 
half, strongly shouldered, and with numerous very fine ribs in 
the upper part. The sinistral portion is large, and the jimction 
of the two is very conspicuous. Long. '035, lat. "019. 
Sab. — Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 



MAZATLA.N TINIVALVES 431 

B. Wliirls with spiral sculpture, 
(a.) Ribs interrupted at the periphery. 

529. Chemnitzia , sp. ind. (d.) 

Tablet 2000 contains a fragment of a very large, wkite, sub- 
diaphanous species, mtli deep grooves between ribs ending at 
the periphery. The mouth must have been '08 long, 
^ai.— Mazatlan ; fragment, off Spondylus ; L'pool Col. 

530. Chemnitzia geacillima, w. s. 

Gh. t. juniore acutissima, maxiine elongatd ; vertice nucleoso 
prolongato, marginibus spirce incurvatis 1 super ante ; anfr. 
primis soliotis/rotundatis ; postea subplanatis ; costis circ. xvi. 
obtusis, circa penpheriam subito tniiicatis ; basi rotundatd, 
I(Bvi ; interstitiis spiraliter tenue decussatis ; aperturd elongatd ; 
columelld vix intortd. 

In most Chemnitzia3, even if the spire outUnes are nearly 
parallel in the adult, they are divergent when young. In this, 
the upper whirls are the sharpest, and scarcely overlap each 
other. The nucleus appears to have been very large. A worn, 
dead sp. appears even sharper than that here measured, with 
fewer ribs. The larger sp. with eight normal whirls, measures 
long. -117, long. spir. '085, lat. '008— '035, div. 13°. 
iZiii.— Mazatlan ; 2 sp. off Chama ; L'pool Col. 

Tablet 2001 contains the larger specimen. 

(b.) Ribs evanescent at the base. 
531. Chemnitzia undata, n. s. 

Ch. t. gracili, tenui, albido-fuscd ; vertice nucleoso marginibus 
spirce subrectis superante ; anfr, (teste juniore) vii. subplanatis, 
suturd profunda ; liris tenuissimis circiter xviii. acutis, vix 
expressis, circa basin evanidis, interstitiis latis, undatis ; striulis 
spiralibus totam superficiem ornantibus, strid majore circa, 
peripheriam ; labro acuta ; columelld gracili, vix tortd. 

On comparing this shell with the corresponding portion of 
C. gracilior, C. B. Ad., it is found to have many fewer and 
much finer and sharper ribs, which do not end at the periphery, 
like the curved interspaces. Long. '065, long. spir. '045, 
lat. -022, div. 14". 
Ba6.—Mazatlan; 2 young perfect sp. off Spondylus; L'pool Col.. 



432 MAZATLAN TJNIVALVE8 

Tablet 2002 contains the larger specimen ; the smallest is of 
a much darker colour. 

532. Chemnitzia flavescens, n. s. 

Ch. t. gracillimd, tereti, flavescerde ; vertice nucleoso heli- 
coideo, marginibus sinrce rectis valcle sibperante, anfr. ui. 
glohosis, verticaliter sitis, apice conspicuo ; anfr. normalihus 
suhplaiiatis, lirulis rectis circiter xx. minime expressis, vix 
acuti^, ad basin evanidis ; striuUs circa basin rotundafam spir- 
alibus ; punctulis creberrimis inter stitia decttssantibiis, sccpe 
elongatis ; aperturd ? 

One somewhat imperfect specimen only of this species was 
found by Mr. Hanley. It is intermediate between C. gracilior, 
(C. B. Ad. Pan. Shells, p. 167, no. 224,) and C. undata. It is 
however more slender than either, and differs from the first in 
the very large size of the sinistral apex, and in the flattening of 
the early whirls, which in C. gracilior arc much swollen in the 
early stage, thoxxgh afterwards they are normally flattened. 
The ribs are also fainter, and the interstitial spiral grooving 
more decided. The specimen presents six normal whirls and 
measures lotig. "ll, lot. "032, div. 13". The sinistral apex is 
fully '01 across. 
^ai^.— Mazatlan ; 1 sp. off Spondylus calcifer ; Havre Col. 

Tablet 2003 contains the specimen, kindly presented by 
S. Hanley, Esq. 

533. Chemnitzia teeebbalis, n. s. 

Ch. t. "Ch. tenuiliratcB" simili, sed curtiore, compactd ; liris 
paucioribus (circiter xx.) ad basin evanidis, supra cxtantibus, 
suturamprofundam coronaniibiis ; coluinelld ad basin productd ; 
labro ad suturam cmarginato. 

A much shorter and broader shell in proportion than C. 
tenuilirata, stronger, Avith the ribs evanescent below the peri- 
phery, and muricating the suture ; they arc not in continuous 
lines. There is a slight slit at the suture, as in Terebra, and 
an approach to an angle at the base of the columella. The 
shell, which has 8 whirls, measures long. "097, long. spir. '071, 
alt. -035, div. 20". 
Hab. — Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 

Tablet 2004 contains the specimen. 



MAZATLAN TTNITAtVES 433 

(c.) Ribs continuous over the base. 
534 Chemnitzia tenuilieata, n. s. 

Ch. t. elongatd, angiistd, albidd ; vertice nticleoso haud 
extante, margimbus spirce rectis hazid superante ; anfr. (testa 
janiore) vi., planatis, suturd angustd, distinctd ; Ihmlis circiter 
xxiv. rectis, a basi ad apicem ascendentibus, circa basin con- 
tinuis ; inter stitiis lineis curvatis deeussatis ; Idbro acuto, 
labio tenui, coliimelld gracili. 

The species is described from a perfect yotmg and a broken 
adult specimen. The latter, when complete, must have 
measured about '23. The young one measures ^o?2^. '065, long, 
spir. -045, lat. '027, div. 15" : {t. adultd, 11".) 
Hab. — Mazatlan ; 2 sp. off Spondylus ; L'pool Col. 

Tablet 2005 contains both specimens. 

535. Chemnitzia unifasciata, n. s. 

Ch. t. tereti, angustd, Jiavescente, fascia densitcs coloratd in 
medio anfractuum sjjiram ascendente ; vertice nucleoso helicoideo, 
satis niagno, marginibtis sjnrce rectis vix superante, haud pro^ 
minente, anfr. ii. subglobosis, verticaliter sitis, apice parum 
conspicuo ; anfr. normalibus planatis, suturd haud conspiaid ; 
lirulis minimis rectis, acutis, circiter xx. circa basin prolonga- 
tam rotundatam continuis ; striulis spiralihus decussanfibus, 
inspird iv., in hasi crebrioribus ; aperturd elongatd; columella 
vix contortd ; labio valido. 

The spiral band of colour can only just be seen in a good 
light, the shell probably being dead ; but it is the only Mazat- 
lan species which possesses the character. In some respects it 
resembles the W. Indian Ch. reticulata, C. B. Ad. .- but the 
tipper whirls are much flatter. The only specimen found has 
5 normal whirls, and measures lo7ig. '09, long. spir. '06, 
lat. -025, div. 18". 
Sab. — Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 

Tablet 2006 contains the specimen. 

Subgenus DUNEEEIA. 

Chemnitzia, anfractibus tumidis, deeussatis. 

This group combines the characters of Chemnitzia and Acbs, 
presenting the mouth of the former with the roimded whirls 
Dec, 1856. no. 



434 MAZATLAN TTNIVALVES 

of the latter. It agrees witli all tlie otlier sections of the 
family in having its limits badly defined. When the forms 
from various seas are better known, the entire family will 
need revision ; meanwhile, for convenience' sake, these species 
are separated with a name in remembrance of Prof. W, Dunker, 
the learned author of lad. Moll. Gain., Monoc/r. Mytil. &c. 

536. DtrjIKEEIA PAUCILIEATA, 71. S. 

D. t. turritd, solidiore, alha ; vertice nucleoso haud producto, 
marginihus spirce rectis haud sitperante ; anfr. rotundatis, 
postice subaiigulatis, suturisprofundis, lirulis acuiis circiter xiv. 
interstitiis latis, uiidatis, spiraliter tenuissime striatis ; aper- 
turd elongatu, subquadrata. 

This species somewhat resembles Parthenia scalariformis, 
but is entirely destitute of the columellar plait. The last 
whirl has perished : the remaining six measui-e long. "083, 
long. spir. '055, lat. '02,7, div. 15". 
Sab. — Mazatlan ; 1 sp. off Chama ; IS pool Col. 

Tablet 2007 contains the specimen. 

537. DUNKEEIA SUBAXGCLATA, W. S. 

D. t. subcylindrica, alba ; vert. nucl. globose, valde declivi, vix 
promiiiente, anfr.n., apice pcBiie cclato, marginibus spirce sub- 
excurvatis hand superante ; anfr. normalibus v. convexis, infra 
suturam valde profundam vix angulatis ; lirulis tran^versis 
tenuihus circiter xx., ad suluram interdum continuis, ad basin 
evanidis, a striis spiralibus, jyarum elevatis, in anfr. penult, iv. 
eleganter canccllatis, interstitiis quadratis ; striis circa basin 
rotundatam magis extantibus, tenuissime in lineis lirularum 
canccllatis ; aperturd subovali. 

Variat, t. minore, liris exiliorihus, crebrioribus. 

The outline of this elegantly cancellated species, when 
young, resembles D. paucilirata : it is then however much 
broader and move angulated, with more numerous ribs, and a 
scarcely twisted columella. In the adult state the lirulw, which 
cease at the suture, arc continued round the base, in the form 
of minute lines decussating the spiral stria;, as these decussate 
the ribs above. A very young sp. with two normal whirls 
measures "032 by "023. The largest in the L'pool Col. with 
four normal whirls, measures long. "067, long. spir. '045, 



MAZATLAN TTNITALVES 435 

lat. *027, div. 18°. Mr. Hanley lio'n'ever found four specimens, 
each witli five whirls, the largest of which measures " 113 by '037. 
Sab. — Mazatlan ; extremely rare, off Spondylus ; L'pool 8f 

Savre Coll. 

Tablet 2008 contains the youngest sp. ; and an adult, present- 
ed by S. Hanley, Esq. 

538. DtTNKEEIA CAXCELLATA, n. S. 

D. t. junior e effusa, rvfo-fuscd, anfr. normalibus ii et dimidio, 
valde tumentibus, vix attingentihus, superne angulatis ; vertice 
nucleoso titmente, heUcoideo, anfr. ii. verticaliter sitis ; lirulis 
plicrimis transversis acutis-iimis, et spiralibus minoribus elegan- 
tissime ca?icellatd ; lahro angulato ; labia rimulam umbilicalem 
circumeunte ; plica coluinellari nulla. 

This exquisitely beautiful yovmg shell looks like an elongated 
Cancellaria without plaits ; it is shouldered as in C. goniostoma. 
The sinistral apex is very prominent. When adult, it must be 
of surpassing elegance. Long. '038, long. spir. "CS, lat. '02, 
div. 15°. 

Sab. — Mazatlan ; 1 young sp. off Spondylus ; L'pool Col. 
Tablet 2009 contains the specimen. 

539. DUNKESIA IXTEE3IEDIA, n. S. 

D. t. alba, elongatd, tenui : vertice nucleoso maximo, anfr. iii. 
helicoideis, verticaliter sitis, prominentibus, apice conspieuo, 
marginibics spires superantibus ; anfr. primis normalibus con- 
vexis, dein subplanatis ; striis spiralibus omnino ornata, tenui- 
bus, obtusis, quarum circiter vii. in spird apparent ; striulis 
tenuibus minoribus transversis evanescentibus vix decussatd ; 
interdum, lirulis evanescentibus irregularibus ; basi subelongatd; 
aperturd ovali ; columelld vix contortd. 

This species is described, although from a single young 
specimen and a broken adult, in consequenc,e of its aberrant 
sculpture, which is more appropriate to AcHs, while the shape 
of the aperture is characteristically Chcmnitzian. The trans- 
verse ridges are only represented, in the young shcU by very 
faint threads, most conspicuous at the sutures, while the spiral, 
somewhat flattened lines are pi'ominent. The young specimen 
has only 3 normal whirls, and measures long. "OoS, lat. '027, 
div. 12". The adult, which has lost the lower whirls, has the 



436 MAZATIiAN tTNITALVES 

decussating transverse tlireacls, extremely faint ; but displays 
very sliglit riblets near the suture, nearly obsolete over the 
body of the whirl. 

i2aZ».— Mazatlan ; 2 sp. o fT Spondlus ; I! pool Col. 
Tablet 2010 contains the younger specimen. 



Genus EULI]\IELLA, Forles. 

Forbes Sf Sanl. Br. Moll. vol. iii. p. 308.— iT. ^ A. Ad. Gen. 

vol. i. p. 233. 
Chenmitzia, pars, Clark, Moll. Mar. Ins. Brit. p. 540, &c. 



540. PEtjlimella obsoleta, n. s. 

Eu. t. valde elongatd, alho-fusca ; lirulis minimis transversis 
infra suturam monstrantihus, basin versics ohsoletis ; striulis 
minimis transversis ornata. 

This species is named, though from an imperfect specimen, 
as being an interesting link between Eulimella and Chemnitzia. 
The apes is unfortunately hidden by a very beautiful incrusta- 
tion which covers part of the spire. It has four whirls, and 
measures '06 by "027. 
Hah. — Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 

Tablet 2011 contains the specimen. 



541. Eulimella , sp, ind. (a.) 

Tablet 2012 contains an imperfect specimen of a beautifully 
glossy and pointed species, with a prominent sinistral apex, 
and subplanatc whirls ; of these the first six measure "057 by 
•028. 
Sab. — Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 



542. Eulimella , sp. ind. (h.) 

Tablet 2013 contains a specimen of normal shape, but with 
the surface too abraded for description. It has 6 whirls, and 
measures -082 by '038. 

£a6.— Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 



MAZATLAN UNIVALVES 437 

543. Etjiimella , sp. ind. {c.J 

Tablet 2014 contains an extremely young slieU of a large 
species. It has only one normal whirl, besides the sunken but 
tumid sinistral apex, and measures '026 by '02. 

Sab. — Mazatlan ; 1 young sp. off Spondylus ; L'pool Col. 

544. , sp. ind. 

Tablet 2015 contains a singular little shell, "024 by '015, the 
fry of a large species, the genus even of Tvhich cannot be deter- 
mined without a series. It has a very large mammillated apex 
of one whu-1, set slanting on the next, which by its subquadrate 
aperture and angulated vunbilicus resembles Niso. 
Sab. — Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 

Genus ACLIS, Loven. 

Ind. Moll. Scand. 1846, p. IQ.—Phll. Sandb. Conch, p. 195.— 
Forbes Sf Saul. Br. Moll. vol. iii. p. 217.— S. &■ A. Ad. 
Gen. i. 234. 

Ebala, Gray. — Alvania, Searles Wood, non Risso. 
In this genus are deposited smooth or slightly sculptured 

shells ; with more or less numerous whirls, tumid or loosely 

spiral, the apes sinistral, and the mouth round or oval, without 

plait. 

545. ACLIS FUSIFOEMIS, n. s. 

A. t. ienui, albidd, ejjfusd, elongata ; vertice nucleoso anfr. ii. 
planatis, subtumentibus, declivi ; anfr. normalibus partim ex- 
curvatis, parum attingeiitibus, valde elongatis ; striulis minimis 
spiralibus, interstitiis minutissime decussatis ; aperturu ovali, 
peritremati continuo, labro acuto. 

The species is described from four very small shells, some- 
what resembling Eissoa proxima, but much more effuse. If 
a large fragment, which has the same sculpture, belongs to 
the same species, it must be a very long and slender shell 
when perfect. The largest of the four, with four normal whirls, 
measures long, "065, long. spir. '042, lat. "022, div. 10°. 
Sah. — Mazatlan ; extremely rare, on Chama ; Upool Col. 

Tablet 2016 contains one specimen and the fragment. 



438 MAZATLAN tTNIVALTES 

54G. ACLIS TTJMENS, 11. S. 

A. t. suhdiapliana, nitidd, alba, inflata ; vertice nucleoso 
minuto, anfr. i. et dimidio, decliviter sito ; anfr. normalibus vi. 
valde tumentihiis ; aperturd rotiindatd, peritremati continuo, 
acuto ; lahio rimulam umhiUcalem monstrante. 

This species is more tumid even than A. ascaris, from which 
it differs in being smooth, with a minute apex. A specimen 
from Java sand appears exactly like in all particulars ; though, 
■with so few characters to judge by in the shell, the animal may 
be distinct. Long. '053, long. sinr. -035, led. -0^4, div. 27°. 
Hah. — Mazatlan ; 1 sp. off Chama ; L'pool Col. — ? Java, 

F. Archer. 

Tablet 2017 contains the specimen (slightly broken.) 

Genus EULIMA, Risso. 

547. EuLiMA Phastata, Soto. 

Conch. 111. sp. 7, f. 10.— Proe. Zool. Sac. 1831, p. 7. — Lam. An. 

s. Vert., vol. viii., p. 451, no. 2. — H. ^ A. Ad. Gen. i. 236. 

Fragments were found of six specimens which may belong to 
this species. The vertex is stout in proportion and rounded. 
Sah. — St. Elena, Cuming. — .^ ]VIazatlan ; extremely rare, off 

Spondylus and Chama ; L'pool Col. 

Tablet 2018 contains 2 (broken) specimens. 

548. EuLiMA , sp. ind. (a.) 

Tablet 2019 contains an apical fragment of a species, much 
smaller than Eu. hastata, Avith the apex not so stout or rounded. 
Sah. — Mazatlan ; extremely rare, on Spondylus ; L'pool Col. 

549. EuLiMA , sp. ind. fb.J 

Tablet 2020 contains fragments of a species, somewhat 
resembling Eu. acuta. Sow. (Proc. Zool. Soc. 1834, p. 8 ; Leios- 
traca a., JI. Sf A. Ad. : non. Eu. acuta, A. Ad.) but appears 
a genuine EtUima. It is remarkable for the extremely slight 
divergence of the spire, though the whirls are not elongated. 
JZaS.— Mazatlan ; extremely rare, on Chama and Spondylus ; 

L'pool Col. 



MAZATLAN TTNIVAIVES 439 

Genus LEIOSTEACA, K. Sf A. Ad. 

Gen. vol. i. p. 237. Shell with a slight varix on each side of 
the spire. The species iu this genus and in Enlima are only 
provisionally divided ; in consequence of the small number 
of specimens, and paucity of specific characters. 

Eulima, pars, auct. 

Balcis, {Leach ms.) Gray, 1S47 ; teste Woodw. 

550. Leiostbaca Peecta, C. B. Ad. 

Eulima recta, C. B. Ad. Pan. Shells, no. 291, pp. 199, 317.— 

H. Sf A. Ad. Gen. i. 237. 

A young shell, perfect though dead, and a fragment, answer 
to the description of this shell, which from the very produced 
base and narrow mouth, as well as the "transverse striae mark- 
ing stages of growth" appears to belong to this genus. The 
Cumingian type is decidedly a Leiostraca. The Mazatlan shell 
has 6 normal whirls, and measures long. ' 105, long. spir. '068, 
lat. -033, div. 20°. 
Ha6.— Taboga, 5 sp. C. B. ^(^a??^. — Mazatlan ; extremely 

rare, on Chama ; L'pool Col. 

Tablet 2021 contains the specimen. 

551. Leiostbaca Psolitakia, C. B. Ad. 

H. Sf A. Ad. Gen. i. 237. 

Eulima sohtaria, C. B. Ad. Pan. Shells, no. 292, pp. 199, 318. 

One nearly perfect shell and some fragments answer to the 
description of this species. It differs from L. iota, var. retexta, 
in being larger, broader, flatter, with the whirls in different 
proportions. Lo7ig. (anfr. ix.) "123, long. spir. "08, lat. '046, 
div. 23". 
Sab. — Taboga ; a solitary specimen in large Holothuria ; 

C. B. Adams. — Mazatlan ; extremely rare, on Spondylus ; 

I/'pool Col. 

Tablet 2022 contains the specimen. 

552. Leiostbaca , sp. ind.. (a.) 

Tablet 2023 contains a specimen intermediate between the 
supposed L. recta and L. sohtaria. It appears to have been of 



440 MAZATIAN UKIVALVE8 

a brownisli wMte. In a genus the species of wHcli present so 
few peculiarities, it is not thought prudent to describe it. It 
seems to have nine whirls, and measures long. '115, long. spir. 
•075, lat. -Olo, div. 23". 
Sah. — Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 



553. ? Leiosteaca , sp. inch (b.) 

Tablet 2024 contains a short stumpy shell ; with the apex 
decollated. It appears to have been brown, and displays a 
continuous jieritreme. It bears some resemblance to the 
AV. Indian L. fulvocincta, C. B. Ad. Contr. Conch, no. 7, p. 111. 
It has four whirls, and measures '077 by '035. 
Hah — ^Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 



554. Leiosteaca likeaeis, n. s. 

L. t. minima, gracillimd, alhd ; axi recta; apice acutd; 
anfr. vs.., prima decliviore ; nitente, vix vancosd ; aperturd 
pyriformi, continud ; labia rimulam umhiliaalem formante ; 
columella hand callosd. 

Distinguished by its minute size, and extremely slender 
growth. The habit is that of Leiostraca, though the varices 
can scarcely be traced. Long. "072, long, spir, '05, lat. '022, 
div. 15". 
Hah. — Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 

Tablet 2025 contains the specimen. 



555. Leiosteaca ? iota, var. betexta. 

Comp. Eulima iota, C. B. Ad. Pan. Shells, no. 290, pp. 198, 

Zn.—Sow. TJies. Conch, in loco.— JT. Sf A. Ad. Gen. i. 236. 
L. ?iota, axi recta. 

The form above indicated accords somewhat better with 
the Panama species than with the British, but is ' entirely 
^^•ithout twist. The British specimens are also sometimes 
straight. The shells in this genus afford so very few distinctive 
characters that no species can be certainly established without 
an accurate knowledge of the animals. The only two specimens 



MAZA.TLAN UNIVALVES 441 

found vary in proportion : tlie smaller, vritli 6 normal turns, 
measimng long. "06, lai. "CSS. 

Tlie larger „ '087, „ "033. 

JSah. — Mazatlan ; extremely rare, off Spondylus ; L'pool Col. 

Tablet 2026 contains tlie larger specimen. 



556. Leiosteaca Pdistoeta, var. tod. 

Melania distorta, Phil. Moll. Sic. vol. i. p. 158, pi. 9, f. 10. 
Eulima distorta, Desk, in Lam. An. s. Vert. vol. viii. p. 454. — 

Pkil. loc. cit. vol. ii. p. Vio.— Forbes Sf Hani. Brit. Moll. 

vol. iii. p. 232.— C/«r^•, Moll. Test. Mar. Brit. p. 451. 
Leiostraca distorta, S. Sf A. Ad. Gen. i. 236. 

L.t. " L. distortcB" similUmd, sed minima; parte suturali 
paululum latiore. 

The type of Leiostraca iota, C. B. Ad. erroneously labelled 
'Jamaica' in Mus. Cuming, and very incorrectly figured by 
Soiv. is somewhat broader and less bent than the Mazatlan 
shells : in other respects it exactly accords. After repeated 
comparison of very fresh specimens with the British dwarf 
variety of L. distorta, the characters appear exactly alike, 
except that the sutural portion, which (the shell being tran- 
sparent) gives an appearance of a spiral line, is shghtly nar- 
rower in the Scarborough specimens received from Mr. Bean. 
The same glossy deposit over the base, with the rather separate 
parietal lip, giving in some directions of light the appearance 
of an umbUicus, appears in each, and of the same shape. No 
difference can be traced in the minute vertex, nor in the varices. 
The colour in fresh specimens exactly accords. The specimens 
in Mr. M' Andrew's collection, grouped under Eu. distorta, vary 
extremely in size and arcuation. The Mazatlan shells are on 
a much smaller scale, geuerallj^ more bent, and most beautifully 
glossy and transparent. The same form occurs m the West 
Indies (B. M.). According to Deshayes (Lam. An. s. Vert. 
vol. viii. p. 455, no. 8) it is found fossil in G-rignon and other 
places. If it extends so far back in time, it is natural that the 
living shell should occupy a widely distributed space. As 
however the animals may be distinct, both in this and in L. iota, 
a name is added expressive of its (for the genus) extreme 
minuteness. The smallest sp. (of 3 normal whirls) measures 
'035 by '016. A remarkably large sp. measures long. "082, 
long, sxiir. *055, lat. "033, div. 18". 



442 MAZATLAN UltlVALVES 

Hah. — ^Norway to Mediterranean, Forbes. — W. Indies, B. M . — 
(Var. Yod.) Mazatlan; 31 sp. living on Spoudj-lus, dead on 
Cliama; L'pool Col. 

Tablet 2027 contains 4 sp. of different ages. The largest 
possesses its operculum, wkicli appears like that of Chrj'sallida, 
but with the rug* much coarser. Another is broken so as to 
shew the axis of the upper whii4s. 



Family CEEITHIOPSIDiE. 

Genus ;CEEITHI0PSIS, Forbes Sf Hani. 

Br. Moll. vol. iii. p. 361.—^. Sf A. Ad. Gen. vol. i. p. 239.- 
Operculum concentric, nucleus terminal. 

PNon Cerithiopsis, Andrew, Ann. Mag. Nat. Hist. vol. s. p. 105. 

Cerithium, pars, auct. — The position of the following species 
must of coiu'se remain in abej-aucc till the animals have been 
examined, or at least the opercida observed. The speci- 
mens found were not sufficiently numerous to make out the 
species satisfactorily. 



557. Ceeithiopsis tttbeeculoides, n. s. 

C.t. " C. tuber culato" simili, sed multo minore ; tuberculis 
minoribus ; avfr. v. primis Itvvibus, tumidis, subdiap/ianis, 
plerumque decollatis ; avfr. nornialibus, lineis radiantibus 
■usque ad carinam quartam non tuberculatam circa perip/ieriam 
continuis ; hasi in t. juniore angulata, sublcevi ; in t. adulta 
carinulis u. tumidiorihus ; labio tenuissimo. 

Comp. C. tuberciilatum, Mont, in Forbes ^ Hani. Br. Moll. 

vol. iii. p. 365. 
Comp. Cerithium Peruvianum, D' Orb. B. M. Cat. Moll. p. 43, 

no. 375. 

The shell is smaller even than dwarf specimens of the British 
species, and the tubercles are further apart ; else the full des- 
cription in the Br. Moll, would apply almost exActly to the 
Mazatlan shell. Tlie smallest sp. with three normal whirls 
measures '055 by '027 ; the largest, with seven, long. '15, 
long. spir. '105, lat. -018, div. 23". 



MAZATLAN irifIVAI,VE3 443 

Sab. — Mazatlan ; 9 sp. offCliama and Spondylus ; L'x>ool Col. 
Tablet 2028 contains an exquisitely perfect young sp. with 
the gl ossy nucleus ; and an adult, vritL. the lip imperfect. 



557 6. Ceeithiopsis Ptubeecttloides, ?;«?*. albonodosa. 

C Hiihei'culoides t, riifo-fusca, tuherculis distantioribm, al- 
bidis ; anfr nucleosis iv.pariim extantihus, suhcarinatis. 

Tablet 2029 contains a young shell and portions of adults 
differing as above indicated. Whether they be of specific value 
cannot be decided till more specimens are found. 
Sah. — Mazatlan ? extremely rare, off Spondylus ; L'pool Col. 



558. Ceeithiopsis ceeea, oi. s. 

C. t. "C. tuherculoidei" simiU, sed alhido-corned, snhdiaphand, 
gracili ; anfr. j)t'imis suhcarinatis, haud, suhito seulpturam 
normalem monstra7itihus ; anfr. tumidioribus, suturis impressis ; 
lineis radiantibus ad peripheriam hand continuis ; carinulis iii. 
ad et infra peripheriam, acutioribus, interstitiis latis, ienuis' 
sime et creherrinie decussato-striatis ; labro tenui, labio vix 
monstrante. 

Only one perfect specimen was found of this beautiful 
species, which differs from C. tuberculoides in its waxen colour 
and texture, in the more deKcate sculpture, and in the pattern 
of the periphery and base. Lonff. '095, long.sjnr.'07, lat.'O^, 
div. 22". 
ffab. — Mazatlan ; 1 sp. off Spondjdus ; L'pool Col. 

Tablet 2030 contains the specimen. 



559. Ceeithiopsis pupifoemis, n. s. 

C. t. " C. iiiberculoidei" slmili, sed niulto minor e, pupiformi, 
mifofasciji, seufusco-aurantid ; anfr. nucleosis, iv. IcBvibus, haud 
elongatis ; normuUbus iv-v., marginibus spirce valde excurvafis ; 
suturis impressis ; carinis valde rotundatis iii. in spird, valde 
tuberculatis, iii. ad et hfra lieripheriam, interstitiis minimis ; 
labro in adultd tenuiore, labia conspicuo. 

This little sheU, in the thiimess and contraction of the 
aperture, somewhat resembles ChrysaUida. Both the complete 



44A MAZATLAN TUriTAlVES 

specimens, by the state of tlie moutli, indicate matnrity ; por- 
tions were found of a very few otliers. Long. (anfr. nucl. 
decol.) -073, loiic/. spi)'. '05, lai. *032, div. 30". 
Sab. — !Mazatlan ; extremely rare, off Spondylus ; L'pool Col. 
Tablet 2031 contains 2 sp. one Avitb complete mouth, the 
other with complete apes ; also an adult labral fragment, which 
may belong to this species. 



560. Ceeithiopsis Soeex, n. s. 

C. t. "C. pupiformV slmili, sed multo minore, tumidiore, gib- 
bosd ; marginibits spirce maxime excurvatis ; anfr. vii. qxiarum 
dimidium nucleosum est, maxime prominens, Iceve; anfr. normali- 
bus sicbifo tiimentibus, planatis, suturd vix impressa ; carinis 
tumentibus ir., iii. in spira maxime twhercnlosis, und ad peri- 
pheriam subtuberculosd, striis in basi plurihus ; labro contracto, 
labia conspicuo ; albidd, purpurea f used fasciatd. 

This remarkable shell looks like a fat Shrew with a promin- 
ent snout. It is quite adult, but it probably varies in colour 
and compactness. Long. "063, long. spir. '043, long. nucl. '01, 
lat. "027, lat. nucl. '007, div. maxime variante. 
Sab. — ]Mazatlan ; 4 sp. off Spondylus ; L'pool Col. 

Tablet 2032 contains a fresh and beautifully coloured speci- 
men. 

561. Ceeithiopsis cox vexa, n. s . 

C. t. gracili, albo fused, inarginibus spires red is ; anfr.x. 
normalibus, valde convexis, suturd profunda, eleganter cancel- 
latis ; cost is spiralibus iv., super castas radiantes c/m/e;* xiii. 
undulantibus, ad intersect iones subnodosis ; interstitiis quadra- 
tis, infus eancavis ; carina cired jyeripheriam hand tuberculosa ; 
basi concavd, sublcevi ; aperturd rotundatd ; labio distincto, 
hand prominente, rimani umbilicalemformente. 

This beautiful species is cancellated as in Phos ; and is 
ramarkable for the convexity of the whirls. The nuclear 
whirls are decollated. Long. 'IS, long. spir. "146, lat. "056, 
div. 12°. 
Sab. — !Mazatlan ; 1 fresh sp. off Spondylus ; L'pool Col. 

Tablet 2033 contains the specimen. 



MAZATT-AK UNIVALVES 445 

562. Ceeithiofsis decijssata, oi. s. 

C. t. conicd, gracili, suhcerea, alhidd, ad hasin ruhro-fusco 
fasciata ; l?aii/'r. primis vi. IcBvibus, prominentibus ;'\ anfr.'vs.. 
norjnalibus, carinis validis, obtusis, circa spiram iii., ad et infra 
peripheriam iii. acutioribus ; iiitei'stitiis subquadratis, a lirulis 
parvis radiantihus distantibus, ad peripheriam continuis, d&cus- 
satis ; carinis spiralibus locis decussatis suhtubercitlosis ; labro 
tenui ; labio vix distincto. 

Only one adult specimen was found of this beautiful species, 
intermediate in sculpture between C. assimilata and C. tuber- 
culata. The transverse lirse seem to pass under the stout keels, 
which are then raised into dull tubercles. The description of 
the nucleus is given with doubt, being supplied from a young 
shell, with only one normal whirl, which therefore does not 
affiHate with certamty to the adult. Long. '16, long. spir. '12, 
lat. -OiS, div. 17". 
Hah. — Mazatlan ; extremely rare, off Chama ; • L'pool Col. 

Tablet 2034 contains the specimens. The lip of the adult 
was unfortunately broken in extracting a minute pebble. 

563. Ceeithiofsis assimilata, C. B. Ad. 

Cerithium assimdatum, C. B. Ad. Pan. Shells, pp. 150, 309, 

no. 194. 
Cerithiopsis assimilatum, H. ^' A. Ad. Gen. i. 240. 
Comp. C. terebellum, C. B. Ad. (Jamaica) in Sow. Thes. Conch. 
Comp. C. trUineatum, Phil, in Sow. Thes. Conch. 

Another allied but very distinct species is C. cereum. Sow. 
from Australia. The Pacific shell is known by its dark reddish 
brown colour, nearly straight outline, very narrow sharp ribs, 
with the broad interstices elegantly decussated. The Mazatlan 
shells are shorter in proportion and of a lighter colour than 
Mr. Cuming's type specimens, in which respects they closely 
resemble C. terebellum. They differ in the sharpness of the 
ribs, which in that species are flattened and broader. There 
are five ribs, of which three appear on tlie spire, one at the 
periphery, and another (smaller) on the base, which is other- 
wise smooth. The first five whirls are smooth and tumid. 
The smallest specimen measures '43 by "22 ; the largest 
long. '2, long. spir. '145, lat. '06, div. 20*. 
Jan. 1857. pp 



446 MAZATIAN UNIVALVES 

Hab. — Panama ; 8 sp. under stones, sponges, marine plants, 
&c. near low water mark ; C. B. Jc?aw5.— Mazatlan ; 20 sp. 
off Chama and Spondylus ; L'pool Col. 

Tablet 2035 contains the smallest and the largest Bpecimens. 



Family SCALAKIAD^. 

Genus SCALAEIA, Lam. 

Phil. Sandh. Conch, p. 178. 

Scala, (Klein,) H. ^ A. Ad. Gen. vol. i. p. 220. 

Clathrus, Oken, Lehrh. p. 257, 1815. 

Cyclostoma, Schum. (teste H. Sf A. Ad.) non Lam. 

564. SCALAEIA HEXAGONA, Sow. 

Proc. Zool. Soc. 1844, p. 29 •.~I7ies. Conch, p. 98, no. 60, pi. 33, 
f. 67.— a B. Ad. Pan. Shells, p. 197, no. 285. 

Clathrus (Scalaria) hexagona, JS. Sf A. Ad. Gen. i. 222. 
Known by the six curves of continuous varices which ascend 

the spire in spiral lines. Long. '62, long. spir. "44, lat. '28, 

div. 30". 

Sab. — Acapulco, Col. Moffat. — Panama ; 1 sp. C. B. Adams. — 

Mazatlan ; 2 sp. ; L'pool Col. 
Tablet 2036 contains 1 specimen. 

565. SCALAEIA SUPEASTEIATA, n. S. 

S. t. turrita, graciliore, cotnpactd ; anfr. normalibus vii. 
attingentihus, roiundatis ; costis xii. acutis, vix superne pro- 
ductis, lineis rectis, marginem alterum spirce parallelis, ascen- 
dentibus ; anfr. primis spiraliter tenuissime striatis, adultis 
Icevibus ; umbilico nullo. 

Differs from S. mitrseformis and its congeners in being 
broader, with the whirls not touching, and the shoulder-pro- 
jections very slight. Only one nearly perfect, and two young 
dead specimens, probably conspecilic, were found. Long. '43, 
long. spir. '27, lai. '25, div. 40". 
ffab. — Mazatlan ; extremely rare ; L'pool Col. 

Tablet 2037 contains the larger specimen. 



MAZATIiAN UNIVALVES 447 

566. ScALAHiA , sp. ind. (a.) 

Tablet 2038 contains a minute shell of four whirls, measur- 
ing '045 by '023, and a fragment displaying sculpture. It is 
elongated, with very numerous (about 15) rounded varices, 
strongly striated spirally. 
Sab. — Mazatlan ; 8 sp. on Spondylus ; L'pool Col. 

567. ScALAEiA , sp. ind. (h.) 

Tablet 2039 contains a minute shell, measuring '06 by "037, 
consisting of 6 whirls, of which 4 are smooth and nuclear. It 
differs from the corresponding portion of S. suprastriata in 
having more numerous (12 sharp) varices, with smooth inter- 
stices. 
£a5.— Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 

568. SCALAEIA EAEICOSTATA, n. S. 

S. t. elongatd, gracili, anfractihus parum rotundatis ; suturd 
parum impressd ; costis paucis, circiter viii. Jiaud semper con- 
venientihus, angustis, Tiaud elevatis ; intersiitlis IcBvibus ; vm- 
hilico nullo. 

The only specimen found, of 6 whirls, though young, seems 
to differ from the early state of all known West-coast species. 
Long. '125, long. spir. '085, lat. "06, div. 33". 
Sab. — Mazatlan ; 1 sp. off Chama ; L'pool Col. 

Tablet 2040 contains the specimen. 

Subgenus CIESOTEEMA, Morch. 

S. Sf A. Ad. Gen. vol. i. p. 223. Shell solid ; varices irregular ; 
whirls generally cancellated. 

569. ClESOTEEMA FUNICULATA, ?n. S. 

C. t. sicbelojigatd, graciliore, alba ; marginibus spira rectis ; 
anfr. ix. prope suturam valde impressam acute angulatis ; 
costibus variantibus (xv. — xx.) hand acidis, angustiorihus, ad 
angulam coronalis, supra basin vix continuis ; anfr. ult. costis 
plei^umque obsoletis, varicibus paucis validis ; costd rotundatd, 
suturam coniinuante, circa basin tumente, a costis radiantibus 



448 MAZATLAN UNIVALTE9 

nodosd ; costd spirali altera lahio adjiciente ; told superjlcie 
mimitissime dectissatd ; labro a costis sinuato. 
Comp. Scalaria diadema, Sow. 

This shell agrees with C. diadema in almost every particular, 
down to the minute decussation of the surface. The remarkable 
pupiform gi'owth of the Peruvian shells however, contrasted 
with the very regular spire (with one more whirl in proportion ) 
of the Panama and Mazatlan specimens, is thought by Mr. 
Cuming sufficient to separate the species. The Mazatlan shells 
are not so large as those in Mr. Cuming's collection, which 
measure long. "7, long. spir. "47, lat. '34, div. 37°. 
Hah. — Mazatlan ; 2 sp . only ; Upool Col. — Panama, 3 sp. ; 

T. Bridges in Mus. Cuming. 

Tablet 2041 contains one pp. with the mouth immature, 
sinuated by both the spiral rope-like ribs. 

Pamilt NATICID^. 

GrENUS NATICA, Adanson. 

Natica, pars, auct. Operculum shelly ; umbilicus twisted. 
Vide S. Sf A. Ad. Gen. vol. i. p. 204. 

570. Natica" maeoccana, Chemn. 

Nerita maroccana, Chem. Conch. Cab. vol. v. p. 270, pi. 188, 

f. 1905—1910 :— ed. alt. pi. 3, f. 10—13, 25, 26 :— icon. mel. in 

pi. 12, f. 1—5. 
Natica maroccana, Q«o?/ ^ Gaim. Voy. Astr. vol. ii. p. 236, 

pi. 66, f. 16— 19.— JToc/i in Zeit. f. Mai. 1844, pp. 151--155.— 

Bunlc. Ind. 3IvU. Guin. p. 14, no. 'io.—21le. in Zcit. f. Mai. 

1847, p. 179, no. 6 -.—do. 1849, p. 36, no. 2 :— do. 1850, p. 165, 

no. 17. 
= Nerita marochicnsis, Gmel. p. 3673, no. ^15. — = Natica 

marochiensis, Rce. Conch. Ic. pi. 13, f. 52 : — (non N. m. Lam. 

An. s. Vert. vol. viii. p. 64;i, no. 25 : = Nerita glaucina, 

Z/?i7i. = Natica intermedia, Phil, olim, = N. Poliana, Sacchi : 

teste Koch, loc. cit.) 
Var. rt. = Naticalurida, Phil. (Chemn. f. 1909—10.) 
Var. b. = Natica unifasciata, Lam . loc. cit. p.'640, no. 19 .■ — Deless. 

Pec. Coq. pi. 32, f. 13 : — teste Koch ; non N. u. auct. nonnul.* 

* It is customary to name Naticte with one band N. unifasciata. Besides how- 
ever the unifasciate var. of N. maroccana, there are other very distinct species. 
M'hich was intended by Lam. cannot be told by the diagnosis alone. 



MAZATLAN tTNIVALVES «*» 

Var. <?. = Natica Chemnltzii, Pfr. in Mart. Conch, p. viii.*— 

a B. Ad. Pan. Shells, p. 201, no. 295— "N. Chemnitzii, 

like." Eve. ms. in Mus. Cum.— CNon N. Chemnitzii, Mke. 

loc. cit. 1849. p. 36— Nee Eed. Voy. Bon. in B. M. Cat. 

p. 22, no. 168.— =Neverita Chemnitzii, H. Sf A. Ad. Gen. 

i. 208.) 
+ Natica Pritcliardi, Forbes, Proc. Zool. Sac. 1850, p. 272, 

pi. 11, f. 2 a-c. 
? + Natica iostoma, 311-e. in Zeit.f. Mai. 1847. p. 178, no. 5. 
Comp. Natica tessellata, Phil, in Zeit. f. Mai. 1848, p. 158, 

no. 20. (Bab. ? ) 

The West-coast shells are extremely variable in size and 
colouring, also in the tumidity of the whirls and elevation of 
the spire. The Mazatlau specimens belong to a small, highly 
coloured variety, -vrhich, with the less coloured larger shells, 
was described by Prof. Forbes as N. Pritchardi. On comparing 
these with a series from W. Mexico, collected by Lieut. Freere, 
and another from the Gambia coast collected by Chief Justice 
Rankin, in the Bristol Museum, also with the series from 
various localities in the British Museum and the Cumingian 
Collections, it does not appear that the local types are suf- 
ficiently distinct to be accounted as separate species. The 
Gambia specimens go thi'ough the same variations of colour as 
those from W. Mexico. The Mazatlau shells much more closely 
resemble the ordinary Gambia type thau the ordinary West 
Mexican type. They are however generally rather flatter in 
the spire, with the subsutural wrinkles rather stronger, and 
the operculum not indented in the inner surface. 

The operculum is thin, shellj^ flat or very slightly concave ; 
with a narrow, not prominent, rounded ridge along the outer 
margin, and another small one boimding the part correspond- 
ing to the umbilical callosity. The whole surface is very finely, 
scarcely perceptibly, spirally striated : at the base rough and 
callous ; the inner margin thickened, and very scabrous. The 
operculum of the Californian form is rather swollen, smooth, 
glossy, with the outside ridge scarcely seen ; the reflex area of 
the callosity scarcely excavated, and the inner margin but 
slightly roughened. It diflers from the Gulf type, much more 
than this does from the Gambian, 

• For justification of the abovo synonyms, v. the elaborate article of Koeh and 
the observations of Danker. If the \V. American shells should prove distinct, 
the name Chemnitzii has precedence over that of Forbes, having been described 
from Mexican specimens, although Meuke applies the synonym to African shells. 



450 mazatlak univalves 

The form appears in tlie Br. Mus. from Demerara, Capt. 
Friend; Philippines, Cuming; N. E. Aush-alia, Jukes; Cape 
York, MacgiWvray ; Swan Eiver ; Port Natal, Krauss ; Eed 
Sea, Major M' Donald. It is quoted by Dunker from Loander 
and Benguela (legit Dr. G. Tarns) ; . and by Menke from 
Bathurst, St. Mary, N. W. Africa (legit Melchers.) In Mus. 
Cuming may be seen many varieties from white to dark, with 
or without zigzag markings and with the spire more or less 
elevated, all from the Society Is. As far as can be judged 
from the diagnosis, the Natiea iostoma of Menke is also a 
variety of the t^ype N. Chemnitzii. 

Either the species is ubiquitous, and therefore suSceptible of 
extreme variation ; or else the characters by which local types 
can be distinguished from each other, have not yet been 
ascertained. The largest of the Mazatlan specimens only 
measures long. '87, long. spir. '22, lat. "82, div. 100". 

An elevated sp. „ '46, „ -12, ,, "42, „ 90". 

A depressed sp. „ "45, „ '08, „ '44, „ 110°. 

Hab. — For various localities, v. supra.— (N. Chemnitzii, Pfr.)^ 

Panama ; 60 sp. on soft mud near low water mark ; C. B.' 

Adams. — Guaymas, Lieut. Green. — Mazatlan ; rare and 

small ; L'2)ool Co/.— (Var. unifasciata.) Guayaquil, Hinds. — 

S. W. Mexico, P. P. C. 

Tablet 2042 contains a young shell. " 08 long, displaying the 
normal shape and colour, with the spire dark purplish brown. 
Also an operculum, "12 long, with the callus on the spire not 
yet worn away ; inner margin cori'ugately serrated, to corres- 
pond with the spiral striula; which are more distinct than in 
the adult. 

Tablet 2043 contains* sp. very young.— 204i, 4 sp. various 
ages. — 2045, 1 sp. with its operculum, and 2 separate opercula. — 
2046, 4 sp. richly coloured, olive.— 2047, 3 do. pattern clouded 
at the end.— 20i-8, 4 do. light shade.— 2049, 3 do. slate colour.— 
2050, 2 sp. shewing diversity of form. 



571. Natica , sp. ind. 

Tablet 2051 contains a minute shell, * long, resembling 
N. maroccana, but of a light buff colour, nuchas smaller, 
upper whirls ilatte