83 



quam internam posito : concavitas flavescens, punctis nitidis 

 notata. Long. 1^ ; alt. l£ ; lat. f poll. Hab. Tongataboo. 



Its surface is like L.jilan, but its form is more venlricose, and 

 its dorsal margin is much less sloping, somewhat alate ; and this 

 is one of its most striking peculiarities. In form it is more like 

 L. undata, except that the reverse extremities correspond. 



Lucina lenticula. Testa parva, solidula, lenticularis, rotun- 

 data, convexiuscula, concentrice imbricato-striata, etiam striis 

 radiantibus decussata, alba, epidermide fuliginoso hie illic induta ; 

 umbonibus fere medianis, prominulis : cardo dentibus apicalibus 

 et lateralibus tenuibus instructus : intus incrassata, alba ; mar- 

 gine crenulato ; impressionibus profundis. Diam. §• ; lat. ^ 

 poll. Hab. Coast of Patagonia ? 



This little shell has rather the aspect of an Astarte orCyprina, 

 and would be considered as such but for its lateral hinge teeth. 



Cardita ventricosa. Testa solida, ventricosa, ovato-trigona 

 vix obliqua, radiatim 18-20 costata, costis concentrice subno- 

 dosis, interstitiis angustis, epidermide fuliginoso, villoso induta ; 

 umbonibus submedianis, obtusis ; intus alba; margine profunde 

 crenulato; dente cardinal! valvae dextrse, elevato, crasso, trian- 

 gulari. Lat. f; alt. f; lat. J- poll. Hab. Puget Sound. 



Compared with C. borealis, Conr., it is thicker, less transverse, 

 more tumid at the beaks, which are less recurved ; the ribs are 

 barred ; the cardinal tooth is short, triangular (not long falcate) 

 and detached from the margin ; the crenulations of the margin 

 deeper. 



Cardita pkocera. Testa elevata, ovato-triangularis, radiatim 

 ad 15-sulcata, (interstitiis convexiusculis) concentrice striata, 

 epidermide fulvo induta; apice mediano, acuto, obliquo ; cardo 

 dente unico triangulari obliquo, instructus ; margine interno sul- 

 cato. Long, f ; alt. f ; lat. -£ poll. Hab. Rio Negro, Pata- 

 gonia. 



It has a more compressed and less oblique form than C. bo- 

 realis, and fewer ribs. The right valve only was obtained. 



Cardium blandum. Testa parva, tenuis, subcircularis, vix 

 transversa, ventricosa, postice subtruncata, cinereo-rufescens, 

 costis planulatis radiantibus ad 40 jnsculpta, sulco angusto 



