41 



triable fact, and has a parallel in the two species (?) de- 

 scribed by Mr. Anthony as Pal. subsolida and P. exilis, both 

 referable to the sexual varieties of one species. (In this 

 connection it may be remarked that two specimens of this 

 variable species served as illustrations of the male and fe- 

 male of Melantho integer in a work on the shells of North 

 America.) Mr. Lea's coarctata is the slender form of the 

 species. His incrassata is an immature specimen, the apex 

 of which has been removed by erosion. If the species re- 

 ally be distinct from ponderosus it should receive the name 

 coarctata or incrassata, either of which has priority of Nolani. 

 A slender variety of M* decisus occurring in Big Prairie 

 Creek has been confounded with the Coosa shell that Mr. 

 Lea calls coarctata. There are peculiarities of form and 

 color that should forbid the association of the Prairie Creek 

 shell with the Coosa River coarctata. 



M. decisus, M. ponderosus and M. rufus occur together in 

 Talladega Creek. They are all in a considerable degree 

 characterized by the shouldered suture which distinguishes 

 Mr. Conrad's geniculus. 



M. lima, Anthony, occurs at Huntsville. It seems to be 

 somewhat nearly related to M. De Campi. W. G. Binney. 

 Possibly a full series of specimens might establish their 

 identity. 



Specimens doubtfully referable to Lioplax subcarinata 

 have been presented as coming from the Coosa river. The 

 specimens referred to have not the peculiar salmon tinted 

 upper whorls that characterize cydostomatiformis from the 

 Coosa and Cahawba rivers, and differ in other respects 

 also. It would be interesting to verify the occurrence of 

 both these species in the Coosa river. 



