ARIONTA. 355 



Helix aeruginosa, Gould, Proc. Bost. 'voc, V. 127 (1855) ; Terr. Moll., III. 12. 



— W. G. Binney, Pac. R. R. Rep., VI. 113 (1857) ; preoc. in Helix. 

 Helix arrosa, Gould, in litt. ; Otia, 215. — W. G. 



Binney, Proc. Acad. Nat. Sci. Philad., 1857, Fig. 238. 



185 ; Terr. Moll., IV. 15, PI. LXXVI. Fig. 4 ; 



L. & Fr.-W. Sh., 1. 163 (1869). — Pfeiffer, Mon. 



Hel. Viv., IV. 350. 

 Aglaja arrosa, Tkyon, Am. Journ. Conch., II. 311 



(1867). 



In the Californian Region, Santa Cruz to Men- 

 docino County, two hundred miles along the coast, 

 only twenty-five miles inland. (Cooper.) 



I have in my cabinet an albino form, and specimens very much smaller than 

 that figured. 



The epiphragm is white, thick, membranous. 



Jaw arcuate, of uniform breadth throughout ; ends blunt ; anterior surface 

 with a few (6) rather distant, stout ribs crenulating both margins (see 

 Fig. 237). 



The lingual membrane (PI. IX. Fig. D) has 54 — 1 — 54 teeth, 17 laterals, 

 180 rows. Teeth of the type usual in the genus. 



The genitalia (PI. XIII. Fig. I) are as in A. Nickliniana. The penis sac is 

 extremely long and gradually tapers into a flagellum. It receives the retractor 

 muscle beyond the middle of its length, and the vas deferens at three quarters 

 of its length from the vagina. The genital bladder is very small, oval, on a 

 very long duct, which has a very long, stouter accessory duct (a d). The 

 vaginal prostate with its bifurcate flagellum was not present in an individual 

 whose genital system was formerly described and figured by me. I have 

 recently observed it in numerous specimens, and it is figured by Semper (Phil. 

 Arch., PI. XV. Fig. 13). d s is a dart sac. The dart is short, stout, acumi- 

 nated, on a broad flat base. 



Arionta Townsendiana, Lea. 



Vol. III. PI. XIX. 



Shell umbilicated, depressed-globose ; epidermis yellowish and brownish 

 horn-color, more or less intermixed ; suture distinct ; whorls 5£, with minute, 

 impressed, longitudinal striae, which can scarcely be traced by the eye, and 

 coarse, oblique wrinkles and striae ; body-whorl large, voluminous, rough, and 

 corrugated ; aperture rather large, somewhat rounded ; peristome white, fully 

 reflected at the base, and but partially so towards its superior part, thickened, 

 and a little projecting internally in the base of the aperture ; umbilicus open, 

 deep, a little contracted by the reflection of the peristome; base convex and 

 turgid. Greater diameter 29, lesser 24 mill. ; height, 16 mill. 



