The Nautilus. 



Vol. XVII. JULY, 1903. No. 3. 



NOTES ON EASTERN AMERICAN ANCYLI. 



BY BRYANT AV^ALKER, 



III. Ancylus obscurus Hald. (1844). PI. I, fig. lG-18. 



I am in great doubt as to the ideiitificv^tion of tliis species. Hal- 

 deman's type, a single specimen, came from the Nolachuoky Eiver, 

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

 from St. Thomas and Porto Rico by Shuttlewortli and from Guada- 

 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 molkisca, are based wholly on 

 the original citation of Shuttlewortli. Both Bourguignat and Clessin 

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

 vise des moUusques 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. H. Dall has quoted it from several localities in Florida 

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



Ilaldeman 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 the author's statement ''apex but slightly 

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



