23 



bu3: natibus prominulis; epidermide tenebroso-fusca, vel luteo-fusca., ad um- 

 bones nitida, radiata ; dentibus cardinalibus crassiusculis, obtuse pyramidatis, 

 corrugatis ; lateralibus longis, crassis corrugatisque ; margarita vel alba vel 

 salmonis colore tincta et valde iridescente. 



If„b. — Luxpalila Creek, near Columbus, Mississippi. W. Spillman, M. D. 



Unio flavidulus. — Testa laevi, elliptica, subinflata,, valde inaequilaterali, pos- 

 tice obtuse angulata, anticS rotunda ; valvulissubtenuibus, antice crassioribus ; 

 natibus prominulis ; epidermide vel luteo-fusca. vel luteo-viridi, eradiatsi ; den- 

 tibus cardinalibus parviusculis, erectis, compre?sis, in utroque valvulo duplici- 

 bu3 ; lateralibus sublongis, lamellatis subrectisque ; margarita alba et irides- 

 cente. 



Hab. — Stream near Columbus, Mississippi. W. Spill.nan, M. D. 



Unio anaticulus. — Testa, laevi, obliqua, ad umbones valde tumida, antice 

 trnncata, postice obtuse angulata, valde inaequilaterali ; valvulis crassiusculis, 

 antice crassioribus ; natibns elevatis, crassis, incurvis, fere terminalibus ; epi- 

 dermide castanea, vittata, obsolete radiata, dentibus cardinalibus subcrassis, 

 subpyramidatis crenulatisque; lateralibus crassis, obliquis subrectisque; mar- 

 garita argentea et iridescente. 



Sab. — Near Columbus. Mississippi. W. Spillman, M. D. 



Unio rcbidus. — Testa, sulcata, subtriangubri, valde inflata, ad latere planu- 

 lata, subasqnilaterali, valvulis subcrassis, antice crassioribus; natibus subpro- 

 minentibus, subinflatis; epidermide tenebroso-rufo-fusca, eradiata, superne mi- 

 '•ante, inferne striata ; dentibu3 cardinalibus crassiusculis, elevatis, subpyrami- 

 datis crennlatisque ; lateralibus sublongis, curvis subcrassisque ; margarita 

 vel rosacea vel alba vel salmonis colore tincta et iridescente. 



Hab. — Tombigbee River, Mississippi. W. Spillman, M. D, ; Coosa River and 

 Big Prairie Creek, Alabama. E. R. Showalter, M. D. 



Unio decdmbens. — Testa laevi, arcuatii, valde compressa, ad latere planulata, 

 inaequilaterali, postice biangulata, antice rotunda; valvulis subtenuibus, antice 

 et po3tice paulisper crassioribus ; natibus prominulis ; epidermide tenebroso-rufo- 

 t'usca, obsolete radiata, transverse striata ; dentibus cardinalibus minimis, sub- 

 compressis, in utroque valvulo duplicibus ; lateralibus praslongis, arcuatis ; 

 margarita purpurascente, et valde iridescente. 



Hab.— Alabama. E. R. Showalter, M. D. 



Unio geemanus. — Testa, laevi, elliptica, subinflata, inaequilaterali, postice sub- 

 biangulati. antice rotunda; valvulis crassiusculis, antice crassioribus ; natibus 

 3ubprominentibus. ad apices concentrice rugoso-undulatis ; epidermide tene- 

 broso-fusca, eradiata, transverse striata; dentibus cardinalibus parvis, erectis, 



