CORBICULA. 1 



scription was prepared, authentic Corb. inci'asmta, Desli., ob- 

 tained from Mr. Cuming, from wliose collection Mr. Ueshayes 

 described this species, are identical with it. 



■7. Corbiciila 1>l'asiliaiia, Deshayes.— C. testa trigona, subtrans- 

 versa, tumidula, insequilaterali, teuue et regulariter trausversim striata, 

 epidermide viridi uitente vestita ; umbouibus uuiuimis, prominulis, oppo- 

 sitis ; latere antico paulo breviori, superne rectiliueo, declivi, postico pa- 

 rurnper attenuate, rotuudaito ; cardiue augusto trideutato, altero bidentato, 

 dentibus minimis diveigentibus, lateraiibus elougatis, angustis, sub leute 

 exilime striatis ; sinu pallii parvulo triangulari, apice acutissimo. 



Hub. South America, at Para, iu Brazil. (Cabinet of the British Mu- 

 seum.) ^ 



Corbicula brasiliana, Deshayes, Biv. Brit. Mus. 1S34, 232. 

 I have not seen any specimens of this species. 



Fossil Species. 



S. CorlJicula truncata, Pkime. — C. testa cordata, inaequiiatera, 

 oblique truncata ; sulcis trausversis, latere antico angulato. 

 Long. .25 mill. 



Hub. North America; (in the State of Kew York'.'). (Cabinets of the 

 Garden of Plants in Paris and of Valenciennes.) 



Cyrena truncata Laiiakck, Anim. s. vert. V, 1818, 553. 



I have never seen this species, which I am inclined to believe 

 does not come from New York, but more probably from some of 

 the Southern States. Mr. Deshayes says in the Encyclopedic 

 Methodique, that it bears such a close resemblance to Ci/rena 

 cuneiformis, that some of the valves of the two species actually 

 fitted into each other. 



9. Corbicula moreauensis. Meek and Hayden. — "Shell ovate, 

 nearly elliptical, compressed, extremities rounded ; anterior end narrower 

 than the posterior, base semi-ovate, most prominent behind the middle ; 

 beaks not much elevated, placed a little in advance of the centre ; surface 

 marked with fine distinct lines of growth; cardinal edge rather thick, and 

 having under the beaks three diverging central teetli in each valve, the 

 anterior of which is the smallest ; lateral teeth two (in the left valve) 

 long, parallel to the cardinal edge, and fitting into corresponding grooves 

 in the other valve; muscular impressions deep." 



Long. 0.90; Lat. 0.66 ; Diam. 0.3G inch. 



Hah. North America, near Jloreau River, Nebraska. Tertiary forma- 

 tion. (Cabinet of the ::mithsoniau Institution.) 



