46 Binney on Terrestrial Mollusks. 



in a well-known and widely circulating Journal. It is, there- 

 fore, surprising that so many authors and collectors have 

 confounded it with Helix clausa, quite a distinct species. 

 Such, however, has been the case, as a reference to the 

 above synonymy will show. It is, however, well known 

 under its correct name by means of the figures published 

 by Binney, Reeve, and Chemnitz, ed. 2. Deshayes is the 

 only one who has figured it under a wrong name. 



Bland has carefully and correctly arranged the synony- 

 my in his valuable " Notes." 



Pfeiffer adds doubtfully to the synonymy H. thyroidus 

 var. edentula. Beck, Ind. p. 23. 



Has been found also in Illinois, (Kennicott). 



The following is Green's description: — 



Shell subglobose, spire elevated, %vhorls six or seven, with 

 numerous oblique wrinkles or striae, sutures deeply impressed, 

 epidermis smooth, and of an olive-brown color, like most of the 

 American Helices, umbilicus closed or masked, aperture slightly 

 contracted at the base, a small callosity on the inner margin of the 

 other lip, near its lower angle ; shell rather more than ^ inch in 

 diameter. 



This shell resembles the H. clausa of Mr. Say, but may very 

 readily be distinguished from that species by the closed umbihcus, 

 the number of its whorls, and its general form. This shell is not 

 uncommon near Charters Creek, Washington Co., Pa. I obtained 

 five or six specimens with but very little trouble ; associates with 

 solitaiia, profunda and palliata. 



HELIX CLAUSA Say. . .vol. ii. p. 107, pi. iv. (excepting the outline figures). 



Helix clausa Say, (Binney's ed.) p. 17, pi. xxxvii. lig. 1. 

 Chemnitz, Bibl. Concb. iii. 60, pi. xiii. fig. 2. 

 Rkkvk, fig. 694. 



Bland, N. Y. Lye. vi. 336; Notes 27. 

 Helix Pennsylvanica Pfeiffer, Ex. parte, Symb. ad Hist. Hel. ii. 36 ; Mon. Hel. 

 Viv. i. 291. 

 Chemnitz, ed. 2, li. 61, ex parte. 

 Reeve, ex parte. No. 676. 

 Helix MilchtUiana Chemnitz, 1. c. i. 332, pi. Ivi. fig. 6-8. 



