1911.] NATURAL SCIENCES OF PHILADELPHIA. 183 



5,700 feet. Cotypes. No. 103.234 A. N. S. P.. collected by Ferriss 

 and Pilsbry, October. 1906. 



The embryonic shell, of 2\ whorls, shows fine subregular ripples 

 along the lines of growth, and in places some fine, very faint spiral 

 striae may be traced ; on the base these spirals are more distinct. They 

 continue there during the first part of the neanic stage, but disappear 

 after a diameter of 8 or 9 mm. has been attained. The main spirals 

 are widely spaced, as in 0. yavapai, but at all stages of growth they 

 are very weak. The embryonic shell is light brown. Some macula? 

 and streaks of opaque cream-white appear after the third whorl. In 

 the adult stage the surface becomes dull white and somewhat chalky 

 from loss of the very thin cuticle, which is present in the embryonic 

 and early neanic stages. 



0. y. profundorum and the allied races, extremitatis and angelica, 

 differ from 0. yavapai by the very weak spiral striation of the enibry- 



Fig. 5. — Spectacle Cove (Station A), from opposite side below Bass Trail. Type 

 locality of OreohelLv yavapai profundorum on the mound at left end of talus slope. 



onic shell. 0. profundorum resembles 0. yavapai, 0. y. ncomexicayia 

 and 0. borbata in having a very short penis, its length about half the 

 diameter of the shell or less. In the strigosa group, so far as known, 

 the penis is long, two-thirds the diameter of the shell or more, in 

 alcoholic examples. 0. yavapai, neomexicana and profundorum are 

 alike in genitalia, but 0. borbata differs by having the retractor muscle 

 inserted on the epiphalliis, whilst in the others it is inserted at the 

 apex of the penis. 



The type locality of 0. y. profundorum is in an embayment of the 

 cross-bed sandstone, where a talus at its foot rests upon the red sand- 



