ARIONTA. 365 



slightly attenuated, blunt ; anterior surface with 3 stout, widely separated ribs, 

 on the central third of the jaw, their ends projecting beyond either margin. 



Lingual membrane (PI. IX. Fig. K) with 60—1—60 teeth, with 20 perfect 

 laterals. The eighteenth tooth has the side cutting point, the twenty-first has 

 a split inner cutting point. 



Genitalia as in Nickliniana. It is figured in Proc. Acad. Nat. Sci., 1874, 

 PI. HI. Fig. H. The ovary is brownish below, yellowish above. The epididy- 

 mis and testicle are salmon-colored. The oviduct is white, the prostate sal- 

 mon. The genital bladder is small, oval, with an extremely long duct, which 

 has a flagellate branch. The duct enters at the lower end of the vagina. The 

 penis sac is narrow, cylindrical, extremely long, with a flagellate extension. 

 The retractor muscle is inserted beyond the middle of the length of the penis 

 sac, the vas deferens at the commencement of the flagellum. There is a stout, 

 long, cylindrical vaginal prostate, whose apex is extended into a flagellum, 

 which shortly becomes bifurcate, there being a bulb-like expansion on each 

 branch just beyond the bifurcation. In some individuals the bulb-like expan- 

 sions are still larger and stouter than in the figure. The cylindrical extension 

 of the vaginal prostate is abruptly truncated, the two flagella entering near ihi 

 eud, not at the extreme terminus. 



Arionta Californiensis, Lea. 

 Vol. III. PL VI. Fig. 2. 

 Shell subperforate, ventricose, subglobular, thin and transparent, shining, 

 delicately indented and granulated, faintly but regularly striate, of a pale yel- 

 lowish horn-color, minutely flecked with pale spots and girded by a narrow 

 brown band, paler at its edges ; spire elevated, whorls 5, convexly rounded, 

 the last very broad, vesicular ; base ventricose ; aperture subcircular, silky and 

 banded within ; the peristome slightly reflected, thickened within, more everted 

 towards its columellar margin, where it is roundly reflected, nearly covering a 

 very small umbilical perforation. Greater diameter 19, lesser 16 milL ; height, 

 15 mill. 

 Helix Californiensis, Lea, Trans. Am. Phil. Soc, VI. 99, PL XXIII. Fig. 79 ; 

 Obs., II. 99 (1839) ; Troschel in Weigm. Arch., 1839, II. 221. — Binney, 

 Terr. Moll., II. 121, PL VI. Fig. 2. -V. G. Binney, Terr. Moll., IV. 13 ; 

 L. & Fr.-W. Sh. I. 170 (1869). — DeKay, N. Y. Moll., 46 (1843), not of 

 Pfeiffer, (?) Chemnitz, Reeve. 

 Helix vincta, Valenciennes, Voy. de la Venus, Moll., PL I. Fig. 2, no descr. — 

 Reeve, Con. Icon., No. 660. — Pfeiffer, Mon. Hel. Viv., III. 183 ; IV. 269 ; 

 in Chemnitz, ed. 2, II. 487, Tab. CLX. Fig. 2 (1854). 

 Arionta Californiensis, Tryon, Am. Journ. Conch., II. 317 (1866). 

 A species of the California Region, near Monterey. I have a specimen with 

 simply a broad white band. Readily distinguished by its thin, delicate shell 

 and globose form. 



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

 with 4-5 distant, stout ribs, crenulating either margin. 



