ARIONTA. 307 



low ; nnibilicus moderate, conical ; aperture very oblique, car-shaped, lunate ; 

 peristome with a white thickening, its ends converging, the right very much 



arched, expanded, the columellar curved and slop- 



, , 111 n . 1- . Fig. 248. 



ing. rollcctcd, expanded above. Greater diameter ^_^ ^ 



29, lesser 2lh mill.; height, 12.^ mill. 



Helix Mormonuni,'^ 1'feiffkr, Proc. Zool. Soc, 1857, 



109; Mon. Hel. Viv., IV. 276. — W. G. Binnky, 



IVir. Moll., IV. 16, PI. LXXIX. Fig. 21 ; L. & 



Fr.-W. Sh., I. 171 (1869). —Fischer and Cuo.sse, 



Moll. Mex. et Ouat., 251 (1870). 

 Aglaja Mormonum, Tkyon, Am. Journ. Conch., II. 



314 (1867). 



In the California Region ; Mormon Island, Califor- 

 nia ; San Joaquin Valley, north to Mount Shasta ; ^ Mormonum. 

 Fresno County to Klamath Lake. It is also said to 



have been found at the Dalles, Oregon, which would give it a much wider 

 northern ran^e. I doubt its existence in Sonora, from which it is also 

 quoted. 



The specimens lately received from California, which appear to be referable 

 to this species, are singularly granulated on the first one and a half apical 

 whorls, and the epidermis of the next two or three whorls is sparingly orna- 

 mented with small but very distinct raised lines or points, something like pros- 

 trate hairs, being part of and same color as the epidermis. 



Animal uniform leaden-color, darker and with a lilac tint on head and ten- 

 tacles. 



Jaw as usual ; 8 ribs. (Cooper.) 



Lingual membrane (PI. XV. Fig. P) as usual in the genus ; teeth 50 — 1 — 50, 

 with 15 laterals, the sixteenth tooth having its inner cutting point bifid. 



Epiphragm as usual in the genus. 



Genitalia (PI. XIII. Fig. E). The general appearance is that of A.fdelh, 

 as formerly described by me, but there is an additional accessory organ (a p g) 

 of use unknown to me. Tlie organ (r) is a dart sac. The dart is short, stout, 

 straight, swollen at its base, and with an enlarged acutely pointed apex (PI. 

 XIII. Fig. F). Upon the vagina, above the insertion of the penis sac, is a 

 ridge-like process (a:), containing in three individuals examined one round and 

 one oblong calcareous nodule (PI. XIII. Fig. G). 



Arionta sequoicola, J. G. Cooper. 



Shell umbilicated, globosely depressed, rather thick, of a light chestnut-color, 

 lighter below, "with a band of darker color revolving above the middle of the 



1 Newcomb says (Free. Cal. Acad., III. 119) that H. cultellata, Thompson, is identical 

 with this species. It does not even belong to the same genus. 



