ACADEMY OF NATURAL SCIENCES. 331 



Regular Meeting, March 18th, 1867. 



President in the Chair. 



Twenty-six members present. 



Messrs. Elisha Brooks, Ellis H. Holmes, L. C. Lane, M.D., 

 John C. Pelton, J. M. Sharkey, M.D., J. A. Bauer, and Robert 

 Hagen, were elected Resident Members, and W. H. Dall a Corres- 

 ponding Member. 



Donations to the Cabinet : Crystal of Borax, from Borax Lake, 

 by Mr. Lightner ; a Bald Eagle, by Dr. Ayres ; a specimen of 

 Wallapi Food, by Frank S. Ailing, El Dorado Canon ; gold-bearing 

 Quartz, from South Carolina, by Gregory Yale ; Wolf Fish, from 

 Frank Johnson ; specimen of Bdellostoma, from Dr. Canfield. 



Dr. Cooper presented the following paper : 



The West Coast Helieoid Land Shells. 



BY J. G. COOPKR, M.D. 



In the article on p. 259, Vol. Ill, of these Proceedings for April 2d, 1866, 

 I suggested a division of the Californian Banded Helices into five subgenera, 

 founded on the shells alone. Since then, Mr. G. W. Tryon has published a 

 synopsis of all of them except H. facta in his " Journal of Conchology," Vol. II, 

 Part 4, for October, 1866, arranging them in the " genera" Aglaia, Arianta and 

 Polymita, but differing essentially from Albers and other authors in the species 

 he assigns to these groups. The types of these subgenera, however, differ so 

 much from our species that it is easy to separate the shells by good subgeneric 

 characters ; and as they inhabit respectively South America, Europe, and Cuba,, 

 it is very probable that the animals differ still more. Until these have been 

 compared, we may well hesitate in referring ours to the same groups, and must 

 for the present be guided by the shells alone. 



• In examining these, the most striking and almost universal character we find: 

 is the presence of a dark band, generally pale margined, on one or both sides,, 

 and situated at or close to the breathing aperture in the animal's mantle, appa- 

 rently having some physiological connection with this opening. It is too uni- 

 form and general to be merely an ornamental marking, such as we find in many 

 species, especially the tropical, which usually show no uniformity in the ar- 

 rangement of their bands. 



The next most constant characters are those derived from the nature of the 

 surface, whether hirsute, with revolving grooves, smooth or variously sculptured, 

 with wrinkles, zigzag or oblique patterns. 



