P H L A S. 



Species 38*. (Fig. a, b. Mus. Brit.) 

 PnoL.\s TKiDENs. Fho. testd clausd, suhoi-ati, canali 

 serratn divisd, parte anticd cnstatd et lineatd, mnr- 

 fjine ventrali injlato, cum margine dorsali eonjluenti ; 

 margine dorsali tumido, divisn, ad vjul/ones trans- 

 verse iiiciso ; parte postird conci'iitncc lineatd, ad 

 terminum tuniis arcaatis duahu.<, ad viargmem pos- 

 ticum integiimenti ci/atlii/ornii ; cijatho intus callo 

 tripartita. 



The ™i;i;e-toothei) Phoi.as. Shell closed, subovate, 

 divided by a serrated canal, anterior jiart ribbed 

 and lineated, ventral margin iiiilated, continent with 

 the dorsal margin; dorsal margin tumid, divided 

 transversely, incised at the uinboes ; posterior part 

 concentrically lineated, with two arched swellings, 

 and at the posterior margin a cup-shaped integu- 

 ment; cup with a tripartite callus within. 



Gi!.\Y (Talona). Brit. Mus. Cat. 



Hub. Monte Christo. 



In some respects resembling riiotas jiapyracca, but 



with a curious three-pronged callus inside the cuj). 



Species 39. (Fig. o, 6, Mus. Brit.) 



PuOLAS TUBIFER. P)io. tcstd clavsd, mbovati, can<di 

 serrato divisd ; parte anticd costatd et lineatd, mar- 

 gine ventrali injlato, mm margine dorsali conjhienti; 

 margine dorscdi tumido, diviso, ad utnbo7ies trans- 

 verse incise; parte posticd concentrice striatd. ad 

 terminum spathulis duabus subquadratis, cor-neis, ad 

 tubam testaceam plus minusve elongatam affixis. 



The tube-beaking Phol.\s. Shell closed, divided by a 

 serrated canal ; anterior part costated and lineated, 

 ventral margin inflated, confluent with the dorsal 

 margin ; dorsal margin tumid, divided trans- 

 versely, slit at the umboes ; posterior part concen- 

 trically striated, with two rather square liorny 

 flaps fi.xed to a more or less lengthened shelly tube. 



SowERBT. Proc. Zool. Soc, 1834. 



Ilab. Bay of Caraccas, AVest Columbia. 



Collected by the late Mr. Cuming in decayed wood. 



Species 40. ( Mus. .Jeffreys, &c.) 



Pholas papyr.\cea. Pho. testd subnjlindraced, clausd, 

 canali serrato divisd, parte anticd costatd et imbri- 

 catd, margine ventrali IcBvi, inflato, margine dorsali 

 conftuenti, usque ad umhones rejle.ro, tumido ; parte 

 posticd lf/;vi, suhlruncatd, ad terminum appendice 

 cyathiformi lateribus subquadratis. 



The papvr.\ceous Pholas. Shell subcylindrical, closed, 

 divided by a serrated canal, anterior part ribbed 

 and imbricated, ventral margin smooth, inflated; 

 dorsal margin confluent, reflected as far as the um- 

 boes, tumid ; posterior part smooth subtruncated, 

 with a square-sided cup-shaped appendage. 



Linnaeus. Sysiema Natur.x'. 



Pholas nana, Pulteney 



Pholas pusilla, Lamarck 



Hab. Great Britain. 



Young. 



A well-known British Species. 



Species 41. (Fig. a, b, Mus. Brit.) 



Puolas concamerata. Pho. tcsid i-entriro.fd, clausd, 

 oblique divisd : parte anticd injlutd, radiatim cos- 

 tatd, cosiis imbricatis, marginibus dorsalibxis late 

 rejle.ris ; parte posticd striatd, ad terminum sub- 

 qnadrutd : in cyatho corneo ad latera diviso, pro- 

 ductd; ad umlxmes lamind subquadratd, magna, 

 pii.-itice aiihiiiiiiniintd : thm laminis du(d>XiS latis 

 cum iiiiir,iiiiihii:< !■ niiin'ilibus testcB confluentibus. 

 The CHA-Mi;r,i:i:n I'iinEAs. Shell ventricose, closed, ob- 

 liquely divided ; anterior part inflated, radiately 

 ribbed, ribs imbricated, dorsal margins widely 

 ' reflected; posterior part striated, subquadrate at 



; the end, produced into a horny cup divided at the 



sid.;s ; a large subquadrate, posteriorly acuminated 

 I subquadrate lamina at the umboes. then two 



! wide lamina; confluent with the terminal marsrins 



j of the shell. 



Desh.wes ? 



I Uah. Monte Key, California. 



