240 CALIFORNIA ACADEMY OF SCIENCES. 



233. Columbella (Astyris) gausapata Guu/d, var. carinata Hinds. 



Plate X, Fig. 10. 



Columbella carinata Hds., Voyage Sulphur, p. 39, PI. X, figs. 15, 16, 1844. Cpr., Brit. Assn. Rept., 

 1863, p. 662. Tryon, Man. Conch., Vol. V, p. 116, PI. XLVII, figs. 35-39, 1883. 

 Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 213. 



Amycla carhiala Hds., Gabb, Pal. Cal., Vol. II, p. 76, 1869. 



Aslyris gausapata var. carinata Hds., Keep, West Coast Shells, p. 35, 1892. 



Shell like A. gausapata, except that it has a distinct keel on the upper part of 

 the whorl. A large series of shells shows mutations between the typical gausapata 

 and this variety. An extreme keeled form gives the following dimensions: Long. 

 8 mm.; lat. 4.1 mm.; body-whorl 5 mm.; aperture 3.5 mm. 



Common in all of the formations at all of the localities in the vicinity of 

 San Pedro; much commoner than C. gausapata. Found also in the Pleistocene at 

 the old irrigating ditch north of Ventura; at bath-house, Santa Barbara; and at 

 Spanish Bight, San Diego. 



The specimen figured is from the upper San Pedro series at San Pedro, and 

 is now in the collection of Delos Arnold. 



Living. — Santa Barbara to San Diego (Cooper). 



Pleistocene. — Santa Barbara to San Pedro (Cooper): San Pedro; Ventura; 

 Santa Barbara; San Diego (Arnold). 



234. Columbella (Astyris) tuberosa Carpenter. 



Plate X, Fig. 7. 



Amycla tuberosa Cpr., Brit. Assn. Rept., 1863, p. 662; Ann. & Mag. Nat. Hist., 3rd Sen, Vol. XV, 

 1865, p. 398. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 229. 



Astyris tuberosa Cpr., Stearns, Proc. Cal. Acad. Sci., Vol. V, 1873, p. 81. Keep, West Coast 

 Shells, p. 36, 1892. 



Columbella tuberosa Cpr., Tryon, Man. Conch., Vol. V, p. 135, PI. L, figs. 40 and 41, 1883. 



Columbella {Astyris) tuberosa Cpr., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 213^ 

 PI. XX, fig. 6. 



Shell small, slender; spire elevated; acute apex; whorls seven, only slightly convex; body- 

 whorl angulated, lower portion decidedly concave and ornamented with narrow grooves and ridges; 

 surface of upper whorls smooth except for delicate incremental lines; suture distinct; aperture ovate, 

 and less than one-half the length of shell; anterior end of columella slender; outer lip thickened 

 by row of tubercles on inner side; inner lip smooth; canal short, straight. 



Dimensions. — Long. 6.5 mm.; lat. 2.8 mm.; body-whorl 4 mm.; aperture 2.9 mm.; defl. 

 22 degrees. 



Distinguishable from other members of genus by slender spire and angulated 

 body-whorl. 



Rare in the lower San Pedro series at Deadman Island and San Pedro; and 

 in the upper San Pedro series at Crawfish George's, Los Cerritos, San Pedro, 

 and Deadman Island. Found also in the Pleistocene at Spanish Bight, San Diego; 



