210 AMERICAN JOURNAL 



0-80. Many specimens even appear higher than wide, which is 

 not the case with any other of the group. Whorls 5 to 5|. 



A. rediynita ? W. G. Binn., 1857. This form connects the 

 last with var. nemorivaga, Val., differing from both in being ob- 

 liquely depressed, so that the mouth approaches the horizontal 

 position, and from the last in being quite imperforate and the band 

 not edged with paler color. Whorls 6, imperforate, thin, granu- 

 lated, reddish-brown, body- whorl swollen ; diam. 0-80, axis 0*48, 

 alt. 0-55, are the essential characters of the description. I have 

 found the most typical specimens at Santa Cruz, but 5J is the 

 usual number of whorls. It perhaps ought to be considered 

 rather a var. of Nlckliniana, as it was by Dr. Binney, but that 

 is always perforate. 



A similar variety of c;'e6ris^r/a^a, Ncavc, is found on Clemente 

 I., being in fact the thin form of which the thick, rough, and 

 obscurely banded types are an extreme. Mr. Binney in letters 

 identified this with redimita, but it has the spire more or less 

 mottled and the faint revolving grooves usually perceptible.* 



The nine forms included in § C, b, ate thus seen to graduate 

 insensibly into each other excepting tudiculata, which, however, 

 has varieties imitating nearly all the others. They approach 

 nearer Arionta arbustorum than § C, a, which have more of the 

 form of Lysinoe^ with the colors and sculpture of the others. I 

 find their jaws agree with that of Arionta, but each distinct. 



The locality, '' San Diego," given by Dr. Lea for Californi- 

 cnsis and Nickliniana, was no more incorrect than many others 

 furnished by Nuttall, but may in part have arisen from his 

 having found imperfect specimens of Kellettii and tudictdata, 

 these, which at that time would naturally be considered varieties 

 of the more perfect shells from near San Francisco Bay. Dr. 

 Binney gives " Sacramento river, U. S. Expl. Exped.," with 

 Nickliniana, but the only species found near its banks are ra- 

 mentosa and tudiculata. 



A. Kellettii, Fbs., 1850. Forbes' locality " San Juan del 

 Fuaco," (see Brit. Assoc. Kept., 1856, p. 239), confounded by 

 some with the Straits of Juan de Fuca, and by others with a 



* As Mr. Binney insists on the identity of redimita with the shell from 

 Clemente Island, althoup;h I am not fully satisfied of it, there is no need of 

 retaining the name for the San Francisco form, so called, as the latter is 

 scarcely a variety of nemorivaga, Val, and both are forms of the true 

 Californiensis, Lea, which I have recently found living within the city 

 limits. All three are distinguished from Nickliniana by the character 

 mentioned, although some come very near it, and, if united, Calif 07'niensis 

 has priority. 



San Francisco, Feb. 7, 1870. 



