i ta 
1923] NATURAL SCIENCES OF PHILADELPHIA 89 
Genitalia much as in S. hinkleyi. The long penis contains a 
spirally plicate papilla somewhat over one-third the total length, 
its end conic. The equally long epiphallus terminates in a very 
short flagellum. The vagina is longer than the penis, and has an 
annular muscular swelling at its distal fourth. The organs measure 
in length: 
HPEMIG ety rset Ss chai ss 13.5 mm. NADINA cc esc doe re 20 mm. 
Penis-papilla....... 50 Museum No......... 43737. 
Hpiphallus:s. 5... - 13.55 DtattOlie../6 vase sees 216. 
Fig. 9.—Sonorella h. cayetanensis, No. 43737, Station 216. 
This form from the northern end of the Cayetano range is ana- 
tomically very close to S. hinkleyi, which inhabits the southern 
end of the same range, and is distinguished by the smaller size and 
more solid texture of the shell. However, there are some specimens, 
such as those from Station 219 (1919) which appear intermediate, 
and we therefore reduce cayetanensis to subspecifie rank. 
Sonorella hinkleyi tumacacori. Plate III, fig. 2; pi. VIII, figs. 4, 5. 
Sonorella tumacdcori P. &. F., Nautilus vol. 33, July, 1919, p. 19. 
Tumacacori Mountains, Stations 2043, 208, 209, 210, 211, 212, 
all on Tumacdcori Peak and the next mountain southward. 
Except by the somewhat greater length of the reproductive 
organs, the decidedly stronger node or swelling on the vagina, the 
short penial retractor and less closely twisted penis papilla, this 
form differs very little from S. hinkley’, of which we now consider 
