45 



subcurtis subreetisque; margaritd Tel alba, vel rosea, vel salmonia et valde 

 iridescente. 

 Hub.— Dallas. Texas. Prof. C. G. Forshey. 



Psio Heermannii. — Testa alata, laevi, elliptica, compressa, valdeinsquilaterali, 

 postice obtuse biangulati, antice rotunda; valvulis subtenuibus, antice irre- 

 gulariter crassioribus ; natibus prominulis, vis undulatis ; epidermide luteo- 

 fusca, micanti, eradiata; dentibus cardinalibus parvis, subconlcis, crenulatis, 

 in utroque valvulo duplicibus ; lateralibus longis, lamellatis subreetisque ; mar- 

 garita pallido-salnionla, purpurescente et intense iridescente. 



Hub. — Medina River, Texas. A. L. Heermann, M. D. 



Usio tessebcl^;. — Testa laevi, quadrata, cuboidea, valde turaida, valde inaequi- 

 laterali, postice obtuse angulata, antice trnncata ; valvulis crassis, ad apices 

 rugoso-undulatis ; epidermide mellea, micanti, radiis interuptis indutis ; den- 

 tibus cardinalibus parviusculis, subconicis corrugatisque ; lateralibus curtis, 

 obliquis rectisque ; margarita argentea et valde iridescente. 



Hub. — Nolachucky River, Tenn. J. G. Anthony. 



Ohio Xorthamptonensis. — Testa laevi, oblonga, valde compressa, ad latere pla- 

 nulata, postice obtuse biaDguIari, anticd obliquS rotundata, valde inaequilaterali ; 

 valvulis subcrassis, antice crassioribus ; natibus prominulis; epidermide vel 

 ochracea vel luteo-fusca, oblique radiata ; dentibus cardinalibus crassis, striatis, 

 in utroque valvulo duplicibns ; lateralibus praelongis, validis, corrugatis, sub- 

 rectis lamellatisque; margarita vel alba vel purpurascente vel salmonis colore 

 tincta et valde iridescente. 



Hab. — Connecticut River, at Nortbampton. At Springfield, by L. Shurtleff, 

 M. D. Below Hartford, T. R. Ingalls, M. D. Neuse River, N. C, E. Emmons, M. D. 



Usio Wardii. — Testa tuberculata, subtriangulari, compressa, subaequilaterali, 

 postice et inferne emarginata, antice rotunda; valvulis crassiusculis, antice 

 cra=sioribu3 ; natibus prominulis, ad apices rugosis ; epidermide vel luteoli vel 

 luteo-virente, maculis triangularis indutis ; dentibus cardinalibus subgrandi- 

 bus, compressis sulcatisque ; lateralibus sublongis, subcrassis, obliquis rec- 

 tisque ; margarita argentei, interdum rosea, et iridescente. 



Hab. — Walhonding River, Ohio, J. C. Ward. Wassepinicon River, Iowa, Dr. 

 Foreman. Coal River, Virginia, Dr.^Hartman. 



Usio Sampsonii. — Testa laevi, oblonga, inflata, ad umbones valde tumida, 

 postice emarginata, antice rotunda, valde inaequilaterali ; valvulis crassis, an- 

 tice paulisper crassioribus ; natibus prominentibus, tumidis, incurvis, ad apices 

 vix nndulatis ; epidermide luteola, radiis viridis vestitis ; dentibus cardinalibus 



