ARIONTA. 359 



the penis is a stout, cylindrical, long, hollow, vaginal prostate, gradually taper- 

 ing at its apex, and extended into a delicate tube, which soon becomes divided 

 into two long flagella. Just beyond the division, on each flagelluni, is a stout 

 bulb-like enlargement. 



Arionta Ayersiana, Newcomb. 

 Shell umbilicated, globosely convex, rather thick, of a dead white with a 

 narrow revolving brownish band, with rough oblique incre- 

 mental stria? deeply cut by coarse revolving lines ; whorls 7, lg ' 

 rather convex, the last globose, descending in front ; spire 

 elevated ; umbilicus small ; aperture oblique, subcircular, 

 banded within ; peristome simple, its ends joined by a light 

 callus, that of the columella widened, reflected over and 

 half concealing the umbilicus. Greater diameter 21, lesser 

 19 mill.; height, lH mill. 



Helix Ayersiana, Newcomb, Proc. Cal. Acad. Nat. Sci., 



II. 103 (1861). —W. G. Binney, L. & Fr.-W. Sh., I. 72, 

 Fig. 120 (1869). 



Aglaja Ayersiana, Tryox, Am. Journ. Conch., II. 312 (1866), 



III. (1867). 



A. Ayersiana. 



Santa Cruz Island ; San Miguel Island ; Santa Rosa 

 Island in the California Region ; not in Oregon, as erroneously stated. 



Animal long and slender, smoky white, covered with white coarse granula- 

 tions running longitudinally down the back, one line of granulations very prom- 

 inent and central, bordered on either side with a deep furrow. Also oblique 

 lines of granulations running down the sides of the foot. Foot dirty white be- 

 low. Tail short, broad, pointed. Some individuals are darker, with a purplish 

 tinge. 



The usual color of the shell is a light chestnut, but from San Miguel Island 

 I have a large individual (30 mill.) of a very dark hue. The shell is sometimes 

 bandless. 



The epiphragm is white, thick, membranous. 



My description and figure are drawn from an authentic specimen. 



Jaw as usual ; 5 ribs. 



The lingual membrane (PI. IX. Fig. H) has 50 — 1 — 50 teeth, with 15 per- 

 fect laterals. The outer laterals have a long inner cutting point, but no side 

 cutting point. 



Genitalia as in A. Tra.ski. The flagellate extensions of the vaginal prostate 

 beyond the bulbs in this species are, however, much shorter and stouter. 



Arionta redimita, W. G. BiNN. 

 Vol. III. PI. VI. Fig. 1, except middle fig. 

 Shell imperforate, globose-conic, rather thin, wrinkled, covered with minute 

 and crowded granulations ; color reddish-brown ; apex free from granules, 



