Vol. 4] Weaver. — Palaeontology of the Martinez Group. 119 



outer edge of the last whorl with the apex makes an angle of 

 about forty-five degrees with the base. The whorls are covered 

 with extraneous objects, which appear to be pebbles of quartz 

 ranging up to 15 mm. or more in diameter. 



Dimensions: — The diameter of the type specimen is 87 mm 

 Height from apex to base, 57 mm. 



Occurrence : — Pound southwest of Martinez, on the west side 

 of the Del Hambre Canon road. This species occurs only in the 

 lower beds of the Martinez group. 



Ficopsis angulatus, a. sp. 



Pl. 13, Pig. 5. 



Spire low, with four or five angular whorls. The body whorl 

 is marked by three prominent equidistant angles which distin- 

 guish it from Ficopsis remondi. The surface between the angles 

 is concave. The surface of all the whorls is marked by numerous 

 sharply defined fine revolving lines and Linear ribs which cut it 

 into minute squares. The space between these ribs is concave to 

 flat. 



Dimensions: — Maximum length from base to apex is 6 mm. 

 The greatest width is 4 mm. 



Occurrence : — About three miles south of Martinez, on the 

 east side of the road to Walnut Creek. It occurs only in the 

 upper beds. 



Urosyca robusta, n. sp. 



Pl. 13, Fig. 1. 



The spire is very low. The whorls number six. On the body 

 whorl there are four very prominent and nearly equidistant 

 nodose revolving ribs. On the lower part of the body whorl there 

 are numerous fine revolving striae. The aperture is broad. The 

 canal is long and from the impression in the matrix appears to 

 be slightly twisted. This species differs from Urosyca can dot a in 

 the constant presence of a fourth revolving nodose rib. 



Occurrence: — This species occurs near the base of the beds. 

 Urosyca caudata has been found in both divisions of the Martinez. 

 Pound southwest of Martinez, on the west side of the road 

 through Del Hambre Canon. 



