ARNOLD] FOSSIL MOLLUSKS FROM CALIFORNIA 43I 



apex subacute. Whorls 5, somewhat angulated medially, convex 

 anteriorly, concave to flat posteriorly, sculpture consisting of not 

 very prominent rounded axial ribs (17 on penultimate whorl), obso- 

 lete above angle, and 2 spiral ridges of about equal importance to 

 the axial ribs, also below the angle, these two systems giving a char- 

 acteristic cancellated appearance to the surface ; the upper margin of 

 each whorl is appressed against the anterior portion of the one pre- 

 ceding and bent back into a little, more or less nodose revolving ridge 

 next to suture ; the area between this revolving ridge and the angle 

 of the whorl is ornamented only by lines of growth which bow 

 convexly posteriorly ; the axial ridges become almost obsolete or are 

 replaced by irregular lines of growth on the body whorl, while the 

 spiral ridges (of which there are 7) become quite prominent, and 

 are separated by channeled interspaces equal in width to the ridges. 

 Suture appressed, wavy, and not very distinct. Columella curved, 

 short and broad, faintly biangularly plicated and with a faint indica- 

 tion of an umbilical chink between it and the incrusted inner lip. 

 Aperture subpyriform ; notch rather prominent, though quite shal- 

 low ; canal short and curved. 



Dimensions. — Altitude, 14 mm.; latitude, 6 mm.; altitude of 

 body whorl, 8.8 mm. ; longitude of aperture, 4.5 mm. ; latitude of 

 aperture, 2 mm.; canal, 1.7 mm. 



Notes. — This stubby little species is more closely related to D. 

 canccllata Carpenter than to any other West Coast form, but is 

 easily distinguishable from the latter by its broader outline, heavier 

 shell, broader columella, fewer and stronger ribs and ridges. A 

 species similar if not identical to D. graciosana is found in the San 

 Diego formation at Pacific Beach, San Diego County. Named for 

 Graciosa Ridge, the type locality. 



Type.— Cat. No. 165,309, U. S. N. M. 



Locality. — Graciosa Ridge, near Folsom well No. 5, Orcutt, 

 Santa Barbara County, California ; locality No. 4476. 



Horizon. — Fernando formation, Pliocene portion. 



DRILLIA WALDORFENSIS, new species 



PI. LIV, fig. 12 



Description. — Shell averaging about 18 to 20 millimeters in alti- 

 tude, slender, spindle-shaped ; apex subacute when perfect. Whorls 

 8 or 9, convex, prominently angulated slightly anterior to middle; 

 portion of whorl posterior to angle has a decidedly concave aspect, 

 which is heightened by a tendency of the posterior margin of the 

 whorl (which is appressed against the preceding whorl) to bend out- 



