OP CONCnOLOGY. 105 



acKticarinaia, Lea. catenoides, Lea. 



apis, Lea. elevata, Lea. 



hella, Conrad. fihim, Lea. 



Boykiniana, Lea. Holstonia, Lea. 



caliginosi, Lea. nodulosa, Lea. 



cancell'jta, Say. Potosiensis, Lea. 



carinocostata, Lea. spinalis, Lea. 



catenaria, Say. tor^a, Lea. 



" Melania, Lamarck. 



Subgen. Melasma, n. & A. Adams, (i. p. 300.-) 



Shell solid; spire elevated, whorls smooth, longitudinally pli- 

 cate; aperture produced anteriorly; inner lip simple, thin; 

 outer lip acute, simple. 



iZawcZa, Lea. Deshayesiana, Lea. 



brevispira, Anthony. JEdgariana, Lea. 



clavseformis, Lea. laqueata, Say. 



Comma, Conr. Lecontiana, Lea. 



concinna, Lea. nitens^ Lea. 



costulata, Lea. plicatula, Lea. 



crebricostata, Lea. plicifera, Lea. 

 Gurreyana, Lea. 



" Genus Hemisinus, Swainson, (i. 302.) 



Shell subulate; whorls smooth, simple, numerous; aperture 

 ovate, anterioi-ly contracted, canaliculate and emarginate in 

 front; outer lip thin, crenulated at the edge. 



Syn. Tania, Gray, Basistoma, Len. 



Ex. H. lineolatus, Wood, t. 32, f. 2, a, &. 



This genus comprises many fine species of fresh-water shells, 

 principally from South America, though a few have been re- 

 garded as inhabitants of other countries. 



bulbosi's, Gould, symmetricus, Conr. lineolatus, Wood.f 

 " Genus ViBEX, Oken, (i. 303.) 



Shell turreted ; whorls tuberculated, spirally ridged or mu- 

 ricate ; aperture subcircular, produced and broadly channelled 

 in front ; outer lip thin, simple. 



Syn. Glavlger, Hald., Melania, Swains., not Lamarck. 



"Subgenus Juga, IL & A. Adams, (i. 304.) 



Shell thin; whorls rounded, transversely 1 irate or furnished 

 with elevated transverse lines; aperture produced anteriorly; 

 outer lip simple, acute. 



*This genus = the plicate species of Goniobasis. M. brevispira, how- 

 ever, is never plicate, although included with the species. 



t The first two enumerated do not belong to this genus, nor have they 

 the shghtest affinity with any of its species. — G. W. T., Jr. 



