18 



Unio cognatus. — Testa laevi, elliptica, crassa, subinflata, valde inaequilaterali, 

 postice obtuse angulata, antice rotundata ; valvulis crassis, antice crassioribns ; 

 natibus subprominentibus; epidermide luteola radiataque ; dentibus cardinali- 

 bus grandibus, crassis, pyramidatis, rugoso-striatis ; lateralibus subcurtis, sub- 

 curvis crassisque ; margarita alba et valdt; iridescente. 



Hab. — Rio Salado, New Leon, Mexico, L. Berlandier, M. D. 



Descriptions of Seven New Species of UNIONIDiE trom the United States. 

 BY ISAAC LEA. 

 [Read July 3d, I860.] 



Unio Lesleti.— Testa laevi, obliqua, subcoiupressa, ad latere planulata, valdi) 

 insquilaterali, postice angulata, antice rotunda; valvulis crassis, antice cras- 

 sioribus; natibus subelevatis ; epidermide luteola, radiis interrupts ; dentibus 

 cardinalibus crassis, eompresso-conicis, obliquis ; lateralibus longis, crassis 

 subcurvisque : margarita alba, et iridescente. 



Bab. — Kentucky, Mr. Joseph Lesley. Tennessee, Mr. J. G. Anthony. 



Unio CASTUS.^Testa. lsevi, inflata, inaequilaterali, postice angulata, antice 

 rotunda, valvulis crassiusculis, antice crassioribus ; natibus subprominentibus ; 

 epidermide micante,luteo-viridi, radiata ; dentibus cardihalibus subgrandibus, 

 ■ ■ompresso-conicis, striatis crenulatisque ; lateralibus subbrevibus, rectis, la- 

 mellatis striatisquc ; margarita alba et iridescente. 



Hab. — South Carolina, Prof. Tuomey. 



Unio Lindsleyi. — Testa, lsevi, elliptica, compressa, ad latere planulata, valde 

 inaequilaterali, postice subbiangulata, antice oblique rotundata ; valvulis sub- 

 crassis, antice crassioribus; natibus prominulis; epidermide vel lutea vel 

 iuteo-oliva, mieante, undique virido-maculata ; dentibus cardinalibus parvius- 

 i-ulis, eompresso-conicis crenulatisque ; lateralibus longis, crassis enrvisque ; 

 margarita alba et iridescente. 



Hab. — Tennessee, President J. B. Linds'ey. 



Unio pekpictcs. — Testa lsevi, elliptica, subinflata, valde inaequilaterali, pos- 

 tice obtuse biangulata, antice rotundata; valvulis tenuibus, diaphanis, antice 

 crassioribus ; natibus prominulis, ad apices undulatis ; epidermide luteo-oliva, 

 subnitida, undique virido-radiata ; dentibus cardinalibus parvis, erectis, co- 

 nicis, crenulatis, in utroque valvulo duplicibus ; lateralibus longis, Iamellatis 

 rectisque; margarita cseruleo-alb& et valde iridescente. 



Hab. — Bull River, Tennessee, President Estabrook, and Holston River, Prof. 

 Troost. 



