CAPSA 



Plate I. 



Genus CAPSA, Brngnutre. 

 Testa ohlongo-transwrsa, suhquadrata, vetitricosa, ad latera 

 paululmn Mans, irueqidlateralis, latere postico longiore, 

 Carclo, in ulrdque valvd dentibm duobua breviius cen- 

 tralibus, quorum, in valvd dextrd, postico majore, sub- 

 recurvo, in valvd sinistra, antico majore, trirjono, so- 

 lido, obtuse bifida. Ligamenium subamplum, externum. 

 Impressio pallii sinu magno, lato. 

 Shell oblong-transverse, somewhat square, a little gaping 

 at the sides, inequilateral, posterior side the longer. 

 Hinge with two central teeth in each valve, of which, 

 in the right valve, the posterior is the larger, a little 

 recurved, iu the left valve the anterior is the larger, 

 triangular, solid, and obtusely bifid. Ligament ra- 

 ther large, external. Impression of the mantle show- 

 ing a large broad sinus. 

 On reference to the ' Encyclopt'die Methodique,' PI. 

 231, it will be seen that the very characteristic bivalve 

 shell represented in the accompanying Plate, the old Ve- 

 nus deflorata of Linnaeus (Sanguinolaria rugosa, Lamarck, 

 Fsammobia riigosa, Sowerby) is there figured by Bruguiere 

 under the generic title of Cafsa. Nearly twenty years 

 afterwards the name was appropriated by Lamarck to dis- 

 tinguish two bivalves ( C. lasvigata and Brasiliensis') which 

 belong more properly to the genus Bonax. This misap- 

 propriation of the term Capsa obtained a wide circula- 

 tion ; it is now restored to the typical Vemis dejlorata of 

 Linnseus, inhabiting a wide range of latitude over tlie 

 Eastern seas, and to a closely allied species from Tahiti. 



Species 1. (Pig. a to/, Mus. Cuming.) 

 Capsa deflokata. Cap. testa oblongo-tramversd, ventri- 

 cosd, radiatim densissime rngosa-striatd et lirald, liris 

 modo tenuibus, modo validioribus, postice semper vali- 

 dibus etplus minus nodoso-crenatis ; albidd, auf carneo- 

 rosaced, aut intense livido-violaced, obscure zonatd et 

 radiatd, intm scepissime lutescente, postice interne pnr- 

 pnreo-violaceo tinctd. 



The DErLOM-ERED Cai'sa. Shell oblong-transverse, ven- 

 tricose, radiately very densely roughly striated and 

 ridged, ridges sometimes thin, sometimes stronger, 

 posteriorly always strong, and more or less nodosely 

 crenated ; whitish, or flesh-rose, or dark livid-violet, 

 obscurely zoned and rayed, interior often yellowish, 

 stained posteriorly with very deep purple-violet. 



Venus dejlorata, Linnasus, Syst. Nat. (12th edit.), p. 1133. 

 Capsa d(fiorata, Bruguiere, Deshayes. 

 Venus versicolor, Gmelin. 

 Venus purpurea, Gmelin. 

 Sanguinolaria riigosa, Lamarck. 

 Psammocola rngosa, De Blainville. 

 Fsammobia rugosa, Sowerby. 



Ilab. Eastern Seas. 



The figures 1 g to 1/ in the accompanying Plate repre- 

 sent lliis well-known species iu all its varieties of sculp- 

 ture and colour, in different stages of growth. 



Species 2. (Mus. Cuming.) 



Capsa Tahitensis. Cap. testa ovato-transversd, tenui- 

 culd, subventricosd, con/ertissime rugoso-liratd, liris 

 posticis tenuibus, elevaiis, svimuricato-squamaiis ; alba, 

 latere antico rotundato, postico, snboblique quadralo, 

 latiusculo, versus marginem compresso. 



Tee Tahiti Capsa. Shell ovately transverse, rather thin, 

 somewhat ventricose, very closely roughly ridged, 

 posterior ridges thin, raised, rather priokly-scaled ; 

 white, anterior side rounded, posterior somewhat ob- 

 liquely square, rather broad, compressed towards the 

 margin. 



Bernaudi, MS. in Mus. Cuming. 



Hah. Tahiti. 



Of lighter structure than the preceding species, more 

 delicately prickly sculptured on the posterior side, which 

 is broader and more S(|uarcly rompressed. 



December, 1856. 



