1916] Packard: Mesozoic and Cenozoic Mactrinae 295 



The type of this species was obtained from University of Cali- 

 fornia Locality 672. R. E. Dickerson described, this station as fol- 

 lows : ' ' Coalinga Quadrangle, Fresno County, California, SE 14 of 

 NW 14 of Sec. 24, T 18 S, R 14 E, Parson's Peak, in Tejon white 

 sandstones. About ten feet below white shale." 



Occurrence. — Eocene: Tejon series, Parson's Peak and the south 

 side of Mount Diablo, California. 



SPISULA ACUTIROSTRATA, n. sp. 

 Text figure 2a and 6 



Shell medium sized, slightly ventricose, trigonal in outline ; in- 

 equilateral ; sculptured by indistinct incremental lines of growth ; 

 beaks prominent, strongly incurved and acutely pointed ; posterior 



a 



Fig. 2. Spisula acutirostrata, n. sp. 2a. type specimen; 2b, left hinge. 

 Both figures natural size. 



dorsal margin somewhat convex; anterior margin also slightly con- 

 vex. Anterior extremity of the cotype produced and slightly trun- 

 cated, while the posterior end is more evenly rounded ; ventral mar- 

 gin arcuate. Escutcheon of the type specimen impressed and broad ; 

 posterior dorsal area limited by a prominent angulation or ridge 

 which extends from the umbo to the posterior extremity. Hinge 

 plate rather wide ; chondophore deep, quite broad ; left cardinal 

 broken, but it was apparently low, heavy and not extending to the 

 ventral margin of the plate. No accessories nor spur observable. 



