500 



PROCEEDINGS OF THE ACADEMY OF 



[Nov., 



Sonorella granulatissima Pilsbry. PI. XIX, figs. 7, 8, 9; pi. XXI, figs. 1-4. 



Proc. A. N. S. Phila., 1905, p. 262, pi. 17, figs. 21-23; pi. IS, figs. 41-43, 

 51-54. 



The typical form is found in Ramsey (figs. 7, 8), Carr and Miller 

 (fig. 9) Canyons. Types were from Ramsey. The shell is distin- 

 guished by its very dense beautiful granulation and the faintness or 

 absence of spiral lines, though on some specimens they are present, 

 but very weak. 



I have examined the genitalia in a number of individuals from each 

 of the three canyons mentioned above. Figs. 1, 2, 3 represents one 

 of the two cotypes. Fig. 4 is from an example from Miller Canyon. 

 The chief feature is that the upper part of the vagina has thick muscular 

 walls, the outer layer consisting of glossy circular muscular fibers. 

 Usually this part is more or less swollen and fusiform. The lower part 

 of the vagina is thin-walled. This feature was conspicuous in every 

 one of about 20 individuals of 12 lots of S. granulatissima and S. g. 

 latior which were examined. The penis is short, its length contained 

 3 or 4 times in that of the vagina. It is abruptly truncate distally. 

 The penis-papilla is quite short, 3.3 to 5 mm. long, cylindric, truncate 

 at the end, and coarsely wrinkled. It is fleshy, perforated by a minute 

 pore, which opens at the end. The rather short epiphallus has no 

 flagellum in any example opened with the exception of one of the 

 cotypes, in which there is a minute, vestigeal flagellum about 0.7 mm. 



5 Measured from a fresh, drowned example. 



