THE NAUTILUS. 



VOL. XVII. JULY, 1903. No. 3. 



NOTES ON EASTEEN AMEKICAN ANCYLI. 



BY BRYANT WALKER. 



III. ANCYLUS OBSCURUS Hald. (1844). PI. I, fig. 16-18. 



I am in great doubt as to the identification of this species. Ilal- 

 deman's type, a single specimen, came from the Nolachucky River, 

 below Greenville, Tenn. It has been cited from Jamaica by Adams, 

 from St. Thomas and Porto Rico by Shuttleworth and from Gnada- 

 loupe by Fischer. The citations of Crosse (J. de C., xl, p. 38) and 

 of Dall and Simpson (U. S. Fish Com. Bull., i, p. 371) of this spe- 

 cies in their catalogues of Porto Rico mollusca, are based wholly on 

 the original citation of Shuttleworth. Both Bourguignat and Clessin 

 question the West Indian localities and Maze in his " Catalogue re- 

 vise des mollusques terrestres et fluviatile de la Guadaloupe," etc. 

 (J. de C., xxxi, p. 29, 1883), states that he had neither found it there 

 himself nor seen it in any of the local collections. More recently, 

 Dr. W. II. Dall has quoted it from several localities in Florida 

 (Proc. U. S. Nat. Mus., 1885, p. 273). 



Haldeman compares the type with A. rivularis and haldemani and 

 his outline figure justifies the comparison. 



Clessin's description is substantially taken from Haldeman, the 

 dimensions given being the same. But his outline figure is quit 

 different and he has modified his description to agree with his figure, 

 placing the apex in the last third of the length and calling it " very 

 obtuse " instead of following (he author's statement "apex but slightly 

 projecting, rather more than one-third of the shell posterior." He 



