98 



PROCEEDINGS OF THE ACADEMY OF [VOL. LXXIV 



the drift of Palm Canyon at Station XII, represent a small, narrow, 

 quite evenly cylindrical form, somewhat different from the majority 

 of Arizona specimens (e.g., drift of Salt River near Tempe, collected 

 by L. -E. Daniels; drift of San Pedro River near Benson, collected 

 by H. A. Pilsbry and L. E. Daniels; foothills of Plumosa Range, 

 Yuma County, collected by George S. Hutson) with which I have 

 been able to compare them. Pilsbry 's original figure, drawn from 

 a Texas specimen, differs in much the same way. The material 

 is, however, too scanty to be considered as showing that the Palm 

 Canyon specimens belong to a race or subspecies realty distinguish- 



Figs. 1-4. Gastrocopta pellucida hordeacella (Pilsbry). Camera outlines of 

 four specimens from Station XII, Palm Canyon, California, showing variation 

 in contour of shell and form of denticles in aperture. 



able from true hordeacella. The specimens are of most interest 

 in that the known distribution of the group of Pupillidae which 

 they represent is thus pushed many miles to the westward. Indeed 

 it is thought that the species is recorded here from the state of 

 California for the first time. 



SUCCINEIDAE 



Genus SUCCINEA Draparnaud 1801 



Succinea avara Say 1824. 



1824. Succinea avara Say, App. Long Exp., p. 2, 60, pi. 15, fig. 6. 

 1885. Succinea avara Binney, Man. Am. Land Sh., p. 31, 33, 36, 59, 337, 

 839, 497, fig. 369. 



