428 TERRESTRIAL AIR-BREATHING MOLLUSKS. 



the lines of growth ; spire acute, of 3 or more moderately convex whorls, sepa- 

 rated by a well-impressed suture, the last whorl large and long, narrowing 

 towards the base ; body portion of the face of the shell 

 moderately large ; aperture ovate, three fourths the length 

 of the shell ; fold of the columella distinct. Length of axis 

 i, breadth 6j mill. 



Succinea rusticana, GOULD, Proc. Bost. Soc. Nat. Hist., II. 

 187 (Dec. 1846) ; Mollusca of Expl. Exped., 28, Fig. 29 

 (1852). PFEIFFER, Mon. Hel. Viv., II. 523. W. G. BIN- 

 NEY, Terr. Moll., IV. 6, PI. LXXIX. Fig. 14 ; L. & Fr.-W. Sh., I. 269 (1869). 

 -TRYON, Am. Journ. Conch., II. 263 (1866). 



Oregon to Tulare Valley, California ; White Pine, Nevada, thus belonging 

 to both Central and Pacific Provinces. 

 For a figure of the animal, see p. 414. 

 Jaw, lingual dentition, and genitalia unknown. 



Succinea Nuttalliana, LEA. 

 Vol. III. PI. LXVII. a, Fig. 4. 



Shell lanceolate-ovate, thin, and fragile, of a dull horn-color, somewhat rudely 

 undulated by the lines of growth ; composed of about 3 tumid whorls, forming 

 a conical spire, the last whorl constituting nearly the whole shell ; suture well- 

 marked ; aperture nearly two thirds the length of the shell ; ovate, broadly 

 rounded in front, the posterior angle being also somewhat rounded by the 

 abrupt curvature of the peristome; columella very gently curved, the region 

 being somewhat gibbous ; no fold on the columella, but in the region of the 

 spire it is slightly sinuous. Length 13, of aperture 10 mill. 



Succinea Nuttalliana, LEA, Proc. Am. Phil. Soc., II. 32(1841); Trans., IX. 4 

 Obs., IV. 4 (1844). PFEIFFER, Mon. Hel. Viv., II. 523. BINNEY, Terr. 

 Moll., II. 81, PI. LXVII. a, Fig. 4. W. G. BINNEY, Terr. Moll., IV. 6 ; L. 

 & Fr.-W. Sh., I. 269 (1869). TRYON, Am. Journ. Conch., II. 236 (1866). 



Oregon and California, in the Pacific Province. 



Jaw as usual ; no anterior ribs. 



The lingual membrane has 19119 teeth (PI. XVI. Fig. R). Another 

 lingual membrane had 50 rows of 30 1 30 teeth ; centrals obtusely tri- 

 cuspid ; laterals bicuspid ; marginals tridentate, the inner tooth much the 

 largest. 



Succinea Oregonensis, LEA. 

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



Shell elongated-ovate, thin, of a somewhat saffron-yellow color, rather 

 coarsely, though obtusely and distantly striated transversely ; spire with 2j 

 or 3 well-rounded whorls, separated by a distinct suture, the last whorl seven 



