EXPLANATION OF PLATE 1 



Pig. la. Leda furlongi, n. sp. X 2. Dorsal view. Type. — No. 12362, Univ. 

 Calif. Mus. Pal., loe. 15. Briones. 



Fig lb. Leda furlongi, n. sp. X 2. Eight valve of type. 



Fig. 2. Pecten raymondi brionianus, n, var. X 1. Left valve. Type. — No. 



12368, Univ. Calif. Mus. Pal., loc. 3532. Briones. 



Fig. 3. Pecten raymondi brionianus, n. var. X 1. Left valve. Cotype. — No. 



12369, Univ. Calif. Mus. Pal., loc. 3532. Briones. 



Fig. 4. Pecten raymondi Clark. X 1. Eight valve. Type. — No. 11581, 

 Univ. Calif. Mus. Pal., loc. 1492. San Pablo. 



Fig. 5. Pecten andersoni gonicostus, n. var. X 1. Eight valve. Type. — No. 



12370, Univ. Calif. Mus. Pal., loc. 1176. Briones. 



Fig. 6. Pecten raymondi Clark. X 1. A very large specimen of the convex 

 left valve. No. 12371, Univ. Calif. Mus. Pal., loc. 1942. Upper San Pablo. 



[160] 



