198 CALIFORNIA ACADEMY OF SCIENCES [Proc. 3D Ser. 



about the correctness of the determination. They have 

 been referred by Arnold to the Miocene of the Kreyenhagen 

 ranch, but the true horizon is that of the Etchegoin Beds, 

 which are probabh' Pliocene. 



Ocairreuce. — This species is common in the Etchegoin 

 Beds of the Mount Diablo Range, at the Kreyenhagen 

 ranch on Zapata Chino Creek. 



Pecten wattsi Arnold. 



Pecten ivattsi Arnold, Tert. and Recent Pectens of Calif., Profess. Paper 

 no. — , U. S. Geol. Siirv. . 



Ocairreuce, — This species occurs with the preceding. 



Pecten etchegoini n. sp. 



Plate XVIII, Figs. 92 and 93. 



.Shell rather large, thick, and ovate in outline; ears nearly equal, costate; 

 ribs strong and grouj^ed in sets of 3 or 4, forming radial undulations in the 

 shell, seen both within and without; margin of valve fluted within. The 

 grouping of the ribs is a variable feature of the shell. In some specimens 

 the depressions are wider, in others narrower than in the one figured. Con- 

 centric lines are usually visible on the shell. 



Occurrence. — The species occurs with the two preceding 

 in the Etchegoin Beds of the Kreyenhagen ranch on Zapata 

 Chino Creek. 



GASTEROPODA. 



Eocene. 



Cypraea fresnoensis n. sp. 



Plate XIII, Fig. 2. 



Shell of medium size, i>^ inches long, i inch in diameter, robust or sub- 

 globose; spire covered; canal produced a little in front. The epidermis 

 covers the spire in adult age, though in the figured specimen it has been 

 removed. The aperture is narrow and curved. The dentition is not shown. 



Occurrence. — This species is rare in the Avenal Sands 

 northwest of Coalinga, western Fresno County. 



