OF CONCnOLOGY. lOt 



solida, Lea. undidata, Say. 



torquata, Lea. Vanuxemiana, Lea* 



'' Genus Leptoxis, Rafinesque, (i. 307.) 



Shell ovate or globose, solid, subperforate ; spire very short ; 

 aperture oval ; inaer lip with a posterior callosity, often 

 anteriorly callous and produced; outer lip thin, sinuous, with 

 a posterior, ascending canal. 



Syn. Anculotus, Say, Anculosa, Swains., Ancylolus. Herm. 



Ex. L. prcerosa, Say, t. 32, fig. 6, a, h. ^ 



The species of this genus are peculiar to tlie North Ameri- 

 can rivers; the spire of the shell has a truncated, eroded apex, 

 and, in the typical species, the shell is solid and subglobose, 

 with the aperture simple in front. 



ahrupta, Lea. ly'dala^ Lea. 



angulata, Conr. ^is^rm, Hald. 



crassa, Hald. plicata, Conr. 



flamviata, Lea. prarosa, Say. 



fuliginosa, Lea. pumilis, Conr. 



fusca, Hald. rubiginosa. Lea. 



fusiformis, Lea. squulida^ Lea. 



gibbosa, Lea. subglohosa^ Say. 



globula, Lea. tsejiiata, Say. 



Grijffi.thsiana, Lea. tintinnahulmn, Lea. 



Hlldrethiana, Lea, triviUatns, DeKay. 



integra, Say. Troostiana^ Lea. . 



melanoides, Conr. turgida, Hald. 



Nlckliniaiia^ Lea. variabilis, Lea. 



nigresceiis, Conr. virgata^ Lea. 



obtusa., Lea. viridis, Lea-f 

 picta, Conr. 



" Subgenus Nitocris, H. & A. Adams, (i. 308.) 



Shell thin, subglobose ; whorls angulated, often carinate ; 

 inner lip subtruncate, or ending in a tubercle. 



carinata, Lea. dilatata^ Conr. 



ccstata^ Lea. dissimilis, Say. 



dent ita, Couth. ebeyia, Lea. 



*Here we find shells belonging to several groups, as pumila, Lea, alveare, 

 Conr., and torquata. Lea, to Slrephobasis ; lima, Conr., and solida, Lea, to 

 Lilhasiii ; undulala. Say, to Pleurocera. Hoeydei, Lea, was never described. 

 Can it be intended for Hydei, Conr. ? Tlie species are generally, however, 

 the ponderous Goniohases of Nortliern Alabama. 



t In the species of tliis genus there are several errors, some quite elon- 

 gated forms being included ; also, a species of Lilhasia. 



