SUCCINEA. 417 



Humboldt Lake, Nevada, in Central Province ; in the Pacific Province at 

 Stockton, Antioch, Mount Diablo, and in San Benito County, in California. 



The original description and figure are given above. 



Jaw as usual ; no anterior ribs. 



The lingual membrane (PI. X. Fig. I) has 24124 teeth, of the type 

 usual to the genus. 



Succinea ovalis, GOULD, not SAY. 

 Vol. III. PI. LXVII. a, Fig. 3. 



Shell ovate, somewhat conic, very thin, pellucid, watery horn-color, some- 

 times tinted roseate ; periostraca shining, very minutely atriate ; whorls 3, the 

 last compressed and elongate when viewed above ; spire short but acute ; suture 

 impressed ; aperture produced by a deep truncation of the shell, elongated, 

 more than three fourths the length of the shell, patulous, expanding anteriorly, 

 exhibiting the interior of the volutions ; when viewed on the side of the aper- 

 ture, the conical shape of the shell appears, the broadest part of the cone is 

 below the centre of the aperture, and it tapers gradually to the apex. Extreme 

 length 15 mill., of aperture 10 mill. 



Succinea ovalis, GOULD, Invertebrata, 194, Fig. 125 (1841), ed. 2, 445 (1870). - 

 ADAMS, Shells of Vermont, 270. BINNEY, Terr. Moll., II. 78, PI. LXVII. a, 

 Fig. 3. W. G. BINNEY, Terr. Moll., IV. 37. PFEIFFEH, Mon. Hel. Viv., 

 IV. 814. MORSE, Journ. Portl. Soc., I. 30, Fig. 77 ; PL IX. Fig. 78 (1864) ; 

 Amer. Nat., I. 607, Fig. 48 (1868). TRYOX, Am. Journ. Conch., II. 237 

 (1866). Not of SAY. 



Succinea Dccampii, TRYON, Am. Journ. Conch., II. 237, PL II. Fig. 23 (1866). 



Canada and the Northern and Middle States, thus belonging to both North- 

 ern and Interior Regions. 



Animal a little longer than the shell, whitish or amber-colored, and translu- 

 cent, with minute black dots, scattered and in clusters of dots upon the surface, 

 most frequent upon the head and upper part of neck. Foot free from dots. 

 A black line running from the ocular points of the eye-peduncles through their 

 length, and along the sides of the neck to the shell, marking the sheath of the" 

 eye-peduncles, which are rather short, thick at base, attenuated towards the 

 end, bulb distinct ; tentacles short, small, and rather conical. Respiratory cleft 

 near the pcristome of the shell, about midway between its centre and its junc- 

 tion with the last whorl. 



It appears to prefer the margins of water on wet and marshy ground, espe- 

 cially where there are fragments of wood saturated with water. We are not 

 aware of its having been found in any other situation. It is also frequently 

 taken on the leaves of flags (/ris versicolor), on the stems of Pontederia and 

 other aquatic plants. 



It deposits its eggs, to the number of about twenty, enveloped in a mass of 

 thin transparent gelatine, at the foot of aquatic plants. These gelatinous 



VOL. IV. 27 



