60 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



Its chief taxonomic features are the large size, depressed spire, 

 wide umbilicus, weakly developed spiral sculpture (especially 

 on the base), rich brown color, and prominent spiral banding. 

 Dead shells of what appears to be the same subspecies are 

 before me from Sespe Canyon above the mouth of Tar Creek, 

 collected by Harold Hannibal, and from Matilija Canyon, col- 

 lected by H. N. Lowe, in May, 1919. Both localities are in 

 Ventura County. 



Epiphragmophora petricola orotes, new subspecies 

 (Plate 4, figs. 5a-5d; plate 6) 



Diagnosis: Shell thin, translucent, depressed-conic, con- 

 spicuously umbilicate, the umbilicus deep, permeable to the 

 apex, and having a diameter about one-ninth the greater diame- 

 ter of the shell. Whorls about 5^, convex, the last descending 

 somewhat in front. Aperture oval and very oblique (45°). 

 Edges of peristome converging and connected by a thin, very 

 delicate, parietal callus. Lip but little thickened and only very 

 slightly reflected save at the pillar, where it tends to cover the 

 edge of the umbilicus. 



Periostracum more or less glossy, often showing quite a 

 high polish. Lines of growth fine and numerous. First half 

 turn weakly radially costate, with a few scattered papillse ; next 

 three-fourths of a whorl finely, closely granulose, with fine, 

 weak incremental costations, and, over all, traces of larger 

 papillae; granulation present to some extent on all remaining 

 whorls, but of diminished importance as compared with the 

 suddenly much increased incremental lines and the papillae ; 

 latter now seen to be ranked, at least primarily, in the usual 

 obliquely retractively slanting series, almost quincuncially ar- 

 ranged, but the appearance of regularity often lost ; maximum 

 development of these papillae attained on the upper surface of 

 the third whorl, still strong on the penultimate whorl, but prac- 

 tically absent from the body whorl except along the suture and 

 within the umbilicus; spiral sculpture very poorly developed, 

 only a few interrupted traces of incised threading being dis- 

 tinguishable on the upper third of the last two whorls, even 

 these becoming entirely obsolete below. 



