THE SMALLER SEA-SHELLS 



175 



Ocinehra michaeli. Ford, Michael's Ocinebra, two 

 good views of which are shown in Figures 165 and 

 166, occurs at Cayucos, San Luis Obispo Co., Cali- 

 fornia. The color of the shell is light gray, with 

 a narrow median band of brown. The figures 

 give excellent details of the 

 shell, though it must be re- 

 membered that they are much 

 enlarged, the real length being 

 only 16 mm. The shell was 

 named for Mr. ,G. W. Mi- 

 chael, who collected the first 

 specimens. 



Ocinehra pouhoni^ Nutt., 

 which somewhat resembles 

 Figure 1 58, has a strong, spin- 

 dle-shaped shell, from one to 

 two inches in length. The 

 shell is rather more slender 

 than the figure, and it has a 

 distinct trace of an umbilicus. 



Its surface is strongly marked with knobby varices, 

 which are crossed by slight spiral ridges and line, dark 

 spiral lines. The walls of the aperture in mature 

 specimens are pure white, and within the outer lips 

 are five or six little round tubercles, or teeth. The 

 canal is open and somewhat curved, and the opercu- 

 lum is a thin, brown scale. The exterior of the shell 

 is gray, while the inside is white. This fine species 

 lives in southern waters, and I have collected beauti- 

 ful specimens at San Pedro. 



Urosalpinx cinereus^ Say, the Oyster Drill, is an 



Fig. 166, X \ 



