LEPTOXIS. 



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Genus LEPTOXIS, Rafinesque. 



Shell ovate or globose, solid, subperforate ; spire very 

 short ; aperture oval ; inner lip with a posterior callosity, 

 often anteriorly callous and produced; outer lip thin, 

 sinuous, with a posterior, ascending canal. 



Syn. Anculotus, Say. Anculosa, Swains. Ancylotus, 

 Herm. 



Ex. L. prgerosa, Say, pi. 32, fig. 6. Operculum, L. 

 prserosa, fig. 6, a, 6, b. 



The species of this genus are peculiar to the North- 

 American 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. 



Species of Leptoxis. 



abrupta, Lea. 

 angulata, Conr. 

 crassa, Hald. 

 flammata, Lea. 

 fuliginosa, Lea. 

 fusca, Hald. 

 fusiformis, Lea. 

 gibbosa, Lea. 

 globula, Lea. 

 Griffithsiaua, Lea. 

 Hildrethiana, Lea. 

 Integra, Say. 

 melanoides, Conr. 

 Nickliniana, Lea. 

 nigrescens, Conr. 

 obtusa, Lea. 

 picta, Conr. 



pilula, Lea. 

 pisum, Hald. 

 plicata, Conr. 

 prasrosa, Say. 

 pumilis, Conr. 

 rubiginosa, Lea. 

 squalida, Lea. 

 subglobosa, Say. 

 taenia ta, Say. 

 tintinuabulum, Lea. 

 trivittatus, De Kay. 

 Troostiana, Lea. 

 turgida, Hald. 

 variabilis, Lea. 

 virgata, Lea. 

 viridis, Lea, 



