Clark: The San Lorenzo Series of Middle California 47 



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Genus Leda 



Leda elongirostrata, n. sp 123 



Leda markleyensis, n. sp 123 



Leda pulehrisinuosa, n. sp 123 



Leda ramonensis, n. sp 124 



Genus Malletia 125 



Malletia packardi, n. sp 125 



Genus Yoldia 125 



Yoldia cooperi tenuissima, n. var. 125 



Yoldia ef. oregona Shumard 12(i 



Family Arcidae 127 



Genus Area 127 



Area (Scapharca) mediaimpressa, n. sp 127 



Area (Scapharca) submontereyana, n. sp 128 



Genus Glycimeris 129 



Glycimeris buwaldi, n. sp 129 



Glycimeris tenuimbricata, n. sp 130 



Family Ostreidae 130 



Genus Ostrea 130 



Ostrea sp. indt 130 



Family Pectinidae 131 



Genus Pecten 131 



Pecten (Lyropecten) gabbi, n. sp 131 



Pecten (Pseudomuseum) alternilineatus, n. sp. 132 



Family Anomiidae 133 



Genus Anomia 133 



Anomia inconspicua, n. sp 133 



Family Mytilidae 133 



Genus Modiolus 133 



Modiolus kikerensis, n. sp. 133 



Modiolus pittsburgensis, n. sp 134 



Genus Mytilus 135 



Mytilus arnoldi, n. sp 135 



Mytilus (Mytiloconelia) Mathewsonii Gabb 135 



Family Periplomidae 130 



Genus Periploma 136 



Periploma undulata, n. sp 130 



Family Thraciidae 137 



Genus Thracia 137 



Thracia condoni Dall 137 



Genus Cyathodonta 137 



Cyatliodonta weaveri, n. sp 137 



Family Pandoridae 138 



Genus Pandora 138 



Pandora (Pandora) acutirostrata, n. sp 138 



Family Lucinidae 138 



Genus Phacoides 138 



Phacoides cf. acutilineatus (Conrad) 138 



Family Diplodontidae 139 



Genus Diplodonta 139 



Diplodonta stephensoni, n. sp 139 



