1916] 



Dickerson: Tejon Eocene of California 



489 



CREPIDULA INORNATA, n. sp. 

 Plate 38, figures 5a, 5b 



Shell subovate, smooth, number of whorls about two and a half ; 

 spire twisted, suture obscure ; deck about a third the length of shell ; 

 margin of deck convex on outside and concave near inner edge. 



This species has been figured as a "high" form of Galerus ex- 

 centricus Gabb but its deck is distinctive of the genus Crepidula. 

 G. excentricus Gabb occurs with it but interior is quite different. 



This species differs from Crepidula (Spirocrypta) pileum Gabb in 

 that its spire is not immersed and the margin of its deck is not convex 

 in the center. 



Dimensions. — Height above base, 4 mm. ; length, 8 mm. 

 Occurrence. — University of California Locality 672. 



CERITHIOPSIS DUMBLEI, n. sp. 

 Plate 38, figure 12 



Shell elongate conical with nine whorls ; the first two nuclear 

 whorls are smooth. The last seven are decorated by four spiral lines 

 of equal strength and equally spaced. Suture linear, impressed, the 

 space between two whorls being of the same width as that between 

 two of the spiral lines. Axial ribs, twelve to fourteen in number. 

 Occasionally these ribs are swollen to form slight varices. Base of 

 body-whorl is decorated by fine spiral threads only. 



This species differs from C. alternata Gabb in that it lacks the 

 minor spiral threads. It differs from C. orovillensis Dickerson in its 

 greater length, in the regular spacing of its four spiral lines and its 

 lack of pronounced varices. 



Named in honor of Professor E. T. Dumble, consulting geologist, 

 Southern Pacific Company. 



Dimensions. — Length, 9.5 mm. ; width of body-whorl, 4 mm. 



Occurrence. — University of California Locality 672. 



CERITHIOPSIS OROVILLENSIS, n. sp. 

 Plate 39, figure 7 



Shell medium in size for this genus, light-colored, conical. Nuclear 

 whorls decollated. A strongly channeled suture separates the post- 

 nuclear whorls. The fourth whorl is marked by three equidistant 

 spiral cords with interspaces equal in width to the cords. About 

 fourteen vertical axial ribs equal in strength to the cords also mark 



