100 PALAEONTOLOGY OF CALIFORNIA. 



OLIVELLA, Swainson. 



O. Matiiewsonii, 11. s. 



PL 18, Fig. 53. 



Small, fusiform, spire somewhat elevated ; whorls five, suture 

 deeply channelled and margined above by a slightly raised rib. 

 Surface smooth. Anterior end, with two or three plications. 

 Aperture acute behind, broad in front, and deeply notched. 



Length, .8 inch. 



Localities : Northeast of Martinez ; collected by Mr. Mathewson. ' Also found 

 abundantly at Alizos Creek, near Fort Te*jon. 



ANCILLARIA, Lam. 



A. ELONGATA, 11. S. 

 PI. 18, Fig. 54. 



Shell small, slender, elongated ; spire high, whorls six, sides 

 flattened, suture obliterated (from an impression in the matrix). 

 Aperture narrow, acuminate posteriorly, columella folded in ad- 

 vance. Surface smooth. 



Length, .4 inch; width of body whorl, .14 inch. 



Two specimens were collected by Dr. Cooper from the most recent Cretaceous, 

 near San Diego. The shell in both cases is very soft and much injured, but the 

 impressions in the matrix still exhibit the surface characters. The long slender 

 form will serve to distinguish this shell from the preceding, even in casts. 



Localities: Near San Diego; Cochran's, east of Mount Diablo; and Clayton, 

 (Division B.) 



FASCIOLARIA, Lam. 



? F. LaEVIUSCULA, n. s. 

 PI. 18, Fig. 55. 



Fusiform, shell thick, spire elevated, whorls? Body whorl 

 convex, smooth, except on the canal, where it is faintly marked 



