3#2 TERRESTRIAL AIR-BREATHING MOLLUSKS. 



has a side cutting point; the twentieth tooth has its inner cutting point split; 

 the outer cutting point of the marginals is very rarely bifid. 



The genitalia of a Catalina Island specimen is figured (PI. XIII. Fig. D). 



The ovary is light yellow. The oviduct is white. The genital bladder is 

 light yellow. The prostate is large and yellow. The whole genital system is 

 long and narrow. The genital bladder is small, globular, on an extremely long 

 and delicate duct which enters the vagina at its upper end. The duct just be- 

 low the bladder receives a branch duct, very long, flagellate, three times the 

 diameter of the duct itself. The penis sac is long, stout, cylindrical, tapering 

 towards its apex and prolonged into a very long delicate flagellum. The vas 

 deferens enters at the point where the flagellum commences. The retractor 

 muscle is inserted half-way between the vagina and the entrance of the vas 

 deferens. Opposite the mouth of the penis sac is a small sac-like organ, prob- 

 ably a dart sac or vaginal prostate. 



As stated* below, this arrangement of the genitalia differs somewhat from 

 that of Stearnsiana. 



Arionta Stearnsiana, Gabb. 



Shell narrowly umbilicated, subglobose, solid, of a dirty white color, irregularly 

 mottled with crowded ashy blotches, grouped into re- 

 * ,g 243, volving series below, with a decided wide, brownish 



revolving band above ; with delicate oblique incre- 

 mental striae, unequally cut by revolving lines; spire 

 elevated ; whorls 5, rather convex ; aperture oblique, 

 semicircular ; peristome simple, acute, its columellar 

 termination white, expanded, reflected over the half- 

 concealed umbilicus. Greater diameter 22, lesser 17 

 mill.; height, 12 mill. 



Helix Stearnsiana, Gabb, Am. Journ. Conch., III. 235, 

 PI. XVI. Fig. 1 (1867). — W. G. Binney, L. & Fr.-W. 

 Sh., I. 177, Fig. 310 (1869). —Fischer and Crosse, 

 Moll. Mex. et Guat., 248, PI. XI. Fig. 5, 5a (1870). 



A. stearnsiana. A. species of the Mexican fauna, common in Lower 



California, from San Tomas River, Todos Santos Bay, 

 Coronado Island, Todos Santos Island ; admitted here, because it is found 

 plentifully within the limits of the California Region around San Diego. 



The shell figured and described was received from Dr. Newcomb. It is en- 

 tirely mature. 



The genitalia (PI. XIII. Fig. B) resemble very nearly those of Kelletti. A 

 comparison of the figures, however, will show considerable difference, especially 

 in the dart sac (13). In the species before me there is a long thread-like duct 

 leading from the base of the dart sac to a large globular organ, (13 d ) whose 

 character is unknown to me. Opposite the entrance of this duct a correspond- 



