3C6 TERRESTRIAL AIR-BREATHING MOLLUSKS. 



One lingual membrane had 176 rows of 56 — 1 — 56 teeth eacli. Another 

 membrane (1*1. IX. Fig. S) had 53 — 1 — 53 teeth. All the teeth are as usual 

 in the genus. The central and fir»t laterals have no distinct side cusps or cut- 

 ting points, though the latter are represented by lateral bulgings on the large 

 cutting point. The side cutting points and cusps are distinctly developed on 

 the ninth tooth. There are about 24 laterals, tlic inner cutting point of the 

 twenty-fifth tooth being bifid. The thirty-ninth and fifty-third (and last) teeth 

 shown in the plate are true marginals. 



The genitalia are as in A. Nickliniana. 



Arionta Carpenteri, Np:wcomb. 



Shell umbilicated, roundly conical, apex obtuse, obscurely marked with 

 one brown band, well striated, under the lens numerous 

 • Fig. 247. very minute spiral striations ; whorls 5|, rounded; suture 



well marked ; aperture circular, with terminations approxi- 

 mating; peristome moderately expanded, at the columella 

 broadly so, but not adherent. Greater diameter, 23 mill. ; 

 height, 16| mill. (Newcomb.) 



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



(March, 1861), II. 103. 

 Aglaja Carpenteri, Tryon, Am. Joum. Conch., II. 313(1866). 

 Helix Kemondi, Tryon, Proc. Acad. Nat. Sci. Philad., 1863, 



281, PI. II. Fig. 1. 

 A. Carpenteri. Arionta Remondi, Tryon, Am. Joum. Conch., II. 318, PI. V. 



Fig. 18 (1866). 



Cinaloa ; Trinidad ; Coronado Island, Lower California ; San Diego and 

 Tulare Valley in the California Region. (Newcomb.) 



The shell figured was received from Dr. Newcomb. 



Jaw as usual ; over 7 ribs. 



Lingual membrane long and narrow. Teeth 48 — 1 — 48, with 20 laterals. 

 (See PI. IX. Fig. U.) It will be seen that the central and first lateral teeth 

 have no side cusps or cutting points ; they appear first on the eighth tooth. The 

 change from laterals to marginals is formed as usual, the inner cutting point 

 of the twenty-first tooth being bifid. A marginal is shown in the thirty-fourth 

 tooth. 



Genitalia as in ^4. Nickliniana, The flagellate ends of the vaginal prostate 

 are shorter in this species. 



Arionta Mormonum, Pfeiffer. 



Shell umbilicated, depressed, rather thin, with arching stria?, light red ; spire 

 scarcely elevated-conic ; whorls 6, slightly convex, gradually increasing, the 

 last convex above and below, rather swollen before, scarcely falling, ornamented 

 above the middle with a chestnut band doubly edged with white, convex be- 



