136 University of California Publications in Geology [Vol. 8 



MACEOCALLISTA ( f ) PACKI, n. sp. 

 Plate 11, figure 4 



Shell elongate-oval in shape ; beaks prominent, being situated one- 

 third the distance from anterior end ; posterior dorsal margin straight, 

 sloping gently to a narrowly rounded posterior end; anterior dorsal 

 margin excavated under the beaks, unusually long; anterior end 

 broadly rounded ; ventral margin slightly arcuate ; shell substance, 

 thin ; surface smooth. 



Dimensions. — Length, 27 mm.; height, 15 mm.; convexity, 4 mm. 



Occurrence. — University of California Locality 790, vicinity of 

 Lower Lake, 1580, Lower Martinez beds north of Mount Diablo, and 

 in the Eocene of San Pedro Point, San Mateo County. 



This species can readily be distinguished from all other venerid 

 species on this coast by its elongate form and by its long anterior 

 dorsal margin. 



Named in honor of Mr. Robert Pack, Geologist, U. S. Geological 

 Survey. 



PAPHIA( «) CLARKI, n. sp. 

 Plate 11, figure 6 



Shell long, narrow, inequilateral; beaks small, placed a third of 

 the distance from the anterior end ; posterior dorsal margin slightly 

 convex, sloping to a narrow rounded posterior extremity ; anterior 

 dorsal margin concave with a very small lunule upon it ; sculpture, 

 small, regularly rounded ribs. 



Dimensions. — Length, 9.5 mm.; height, 6 mm.; convexity, 2 mm. 



Occurrence. — University of California localities 790 and 784, 

 vicinity of Lower Lake; basal Martinez and Trochocyathus zitteli beds 

 north of Mount Diablo. 



This form resembles Tapes conradiana Gabb closely, but is a shorter 

 form with finer ribbing. The specimens found are all small ones. 



Named in honor of Mr. B. L. Clark, Instructor in Palaeontology, 

 University of California. 



TELLINA HERNDONENSIS, n. sp. 

 Plate 11, figure 9 



Shell moderate in size, longer than high ; beaks nearly central, 

 prominent. Posterior dorsal margin, straight with slightly greater 

 slope than the posterior dorsal margin. Posterior end narrowly 



