EXPLANATION OF PLATE 48 



All figures approximately natural size 



Fig. 1. Modiolus gabbi, n. sp. Longitude, 69 mm. Apparently a very char- 

 acteristic species of the Upper Miocene. 



Fig. 2. Pecten pabloensis Conrad. Left valve. Longitude, 33 mm. 



Fig. 3. Pinna alamedensis Yates. Longitude of imperfect specimen, 135 mm. 

 A very common species in the Upper San Pablo. Also reported from the Lower 

 Miocene of Southern California. 



Fig. 4. Glycimeris septentrionalis Middendorf. Longitude, 24 mm. 



Fig. 5. Area trilineata Conrad. A very common species in the Upper Mio- 

 cene and Pliocene of the west coast. Also reported from the Lower Miocene. 



Fig. 6. Yoldia carnarosensis, n. sp. Longitude, about 40 mm. 



Fig. 7. Mytilus merriami, n. sp. Longitude, about 105 mm. 



Fig. 8. Mytilus merriami, n. sp. Same specimen as figure 7. 



Fig. 9. Glycimeris coalingensis Arnold. Specimen from Lower San Pablo. 

 Longitude, 32 mm. 



Fig. 10. Glycimeris coalingensis Arnold. Specimen from Upper San Pablo. 

 Longitude, 36 mm. 



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