and Xote on H. MobUiana, Lea. 363 



Pfeiffer, I placed this species in the synonvmv of H. jejuna, 

 Say, having be tore me adult specimens from Georgia, and 

 others, immature, from Florida. W. G. Binney (Terr. 

 Moll., IV, 67, 185^'), Tryon (Amer. Jour. Conch., II, 308, 

 18(36), and Binney and Bland (Land and Fresh-water Shells, 

 Part I, 151, 1869) adopted this view. Having since the 

 larter date acquired specimens from Baldwin, Florida, col- 

 lected by Col. Jewett and the late Dr. Hubbard, also from 

 Molnle, by ^Ir. Mohr, I am satisfied that two species have 

 been confounded, — that H. Jlobiliana, Lea, is distinct from 

 the small species, knuwn especially from the vicinity of 

 Savannah, Ga., now recognized as U. jejuna. 



The ligures in Terr. Mull., pi. xlii, f. 2, of Tryon (I.e.), 

 pi. V, f. 3. and Land and Fresh-water Shells, tig. 2d8, are 

 ot" a. jejuna and do not represent Lea's species. 



In H. Mohiliana there are six whorls ; the last whorl is re- 

 markably constricted and gibbous at the aperture, more 

 tumid at the base and with smaller umbilicus than in jejuna. 

 The microscopic spiral lines on the embryonic whorls of the 

 latter are absent in the former. The peristome at its junc- 

 tion with the penultimate whcjrl is sharp, nut reflected nor 

 thickened, but elsewhere reflected, thickened by a whitish 

 callus within, the edge of which forms a distinct portion of 

 the peristome, and has an obsolete tooth-like development 

 .near the columella. The aperttire is more lunate than in 

 jejuna. 



H. MobiJiana may be compared, so far as regards the 

 tumid ba.-e, small umbilicus, constricted aperture and gib- 

 bous character of the superior part of the last whorl behind 

 the aperture, with a Texan form in my cabinet of H. Bev- 

 landieriana. 



The measurements of my largest specimen (six whorls) of 

 H. ^lobUiana, from Baldwin, are as follows : Diam. : maj. 

 10, miu. 7 mill. ; alt. 6 mill. 



[Printed at the Satem PeesS. Jan., 1571. 



