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 Corresponding 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. Alling, El Dorado Cañon; 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 Helicoid Land Shells.
BY J. G. COOPER, M.D.
In the article on p. 259, Vol. III, 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, apparently having some physiological connection with this opening. It is too uniform 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 arrangement 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.