172 PALAEONTOLOGY OF CALIFORNIA. 



MARGAKITELLA, M. & H. 



M. ANGULATA, n. 8. 

 PL 28, Fig. 55. 



SHELL small, thin, highly polished, spire elevated; whorls four 

 and a half, convexly flattened on the sides, more or less truncated 

 above ; body whorl very slightly convex on the base. Surface 

 bearing one, two, or three strongly impressed lines near the suture, 

 crossed by oblique impressed lines forming variable series of crenu- 

 lations ; these oblique lines rarely extend far down on the sides, 

 but hold the same direction as the lines of growth, which can 

 occasionally be traced their entire length ; besides these, there 

 are sometimes faint revolving lines visible over the entire surface, 

 more constant on the base ; umbilicus moderate, its margin evenly 

 crenulated, its internal surface marked by strong revolving and 

 radiating lines. Aperture subquadrate, margins simple. 



Length, .25 inch ; width, .23 inch. 



From the Martinez or Chico Group, Martinez. There is a small deposit of the 

 latter group near Martinez, and judging from the lithological character of the 

 specimens, they seem to have come from it ; they were sent me by Mr. Mathewson. 



This species can be distinguished from M. crenulata by its higher spire and 

 narrower umbilicus ; they approach each other in the crenulation of the top of 

 the whorl and the umbilical margin. 



ACM^A, Esch. 

 ? A. TEJONENSIS, n. s. 



PL 28, Fig. 56. 



SHELL small, low, ends unequal; anterior end broad, sides con 

 verging posteriorly ; posterior end narrow, rounded ; apex sub- 

 central, slightly curved forwards. Surface marked by a few con 

 centric lines, and six or eight faint radiating undulations. 



Length, .35 inch ; greatest width, .25 inch; height, .1 inch. 



