OP CONCHOLOQY. 53 



NOTE ON HELIX RUFA, DE KAY. 



BY E. MICHENER, M.D., AVONDALE, CHESTER CO., PA. 



Mr. Wm. G. Binney, when speaking of Helix albolabris, 

 Say, remarks, that "Helix rufa, DeKay, appears to ,be the 

 young of this species." — "Supplement to Binney 's Terrestrial 

 Mollusks," p. 44. 



Again, under Helix thyroides, Say, speaking of its varieties, 

 he says: — -"One from Germantown, Pa., is very small, mea- 

 suring only 15 millimetres in diameter. It is globose, shining, 

 sometimes imperforate, and generally without the parietal 

 tooth. It is impossible to distinguish it from forms of H. hue- 

 culenta." Of the latter, he gives H. thyroides, var. B. of 

 Pfeiffer, as a synonym. 



Now, the Germantown variety of H. thyroides also occurs 

 in this vicinity, and agrees exactly with DeKay 's description 

 of H. rufa. I have not, however, found it imperforate, and 

 the parietal tooth is generally slightly developed in mature 

 shells. 



The young shells of H. albolabris and H. thyroides closely 

 resemble each other, perhaps cannot be distinguished, except 

 by color in the rufous variety of the latter. 



I would designate this shell as 



Helix thyroides, var. rufa, 



Synonym, Helix rufa, De Kay, 



and if it is "impossible" to distinguish between this and H 

 bucculenta, Gld., I would add it also to the synonymy.* 



* Note by the Editor. — We think, with our correspondent, that H. bue- 

 eulenta is, probably, identical with DeKay's species; at least, we can per- 

 ceive no difference between it and what has hitherto been regarded as the 

 Philadelphia form of H. thyroides. The more globose form, darker color, 

 smaller size, etc., serve to distinguish it from thyroides. We are inclined 

 to consider it a distinct species, however, rather than a variety. Its geo- 

 graphical distribution is extensive. DeKay gives the localities, Rockland 

 and Orange Counties, New York ; and Dr. Gould, Georgia to Texas. To 

 these I add the following, of specimens in my cabinet, Newbern, N. C.; 

 Antietam, Md.; Trenton and Atlantic City, N. J.; Germantown, Pa. 



