534 PEOCEEDINGS OF UNITED STATES NATIONAL MUSEUM. [1885. NOTES ON THE MOLLUSKS OP THE VICINITY OP SAN DIEGO, CAL., AND TODOS SANTOS BAY, LOWER CALIPORNIA. By CHARliES R. OB€UTT,* with comments by IV. O. I>Ar.Ki. During the past few years I have made extensive collections, mainly of littoral shells, in this vicinity, and have had opportunity for making hasty notes and collections while botanizing on the shores of All Saints (Todos Santos) Bay, situated about 50 miles south of San Diego. From material collected, the marine fauna of San Diego appears to possess a larger number of the species of the Lower Californian coast than of the Californian i^rovince to the north, while few species can be considered as locally characteristic with our present knowledge of their distribu-tion. San Diego Bay is protected on the west by a high promontory, Point Loma, with a rocky ocean beach and a shingle beach by the entrance to the harbor. Inside of the entrance is an extensive bed of clay and boulders at what is known as La Pl+iya, and this station forms the prin-cipal home of the pholads, rock pectens {Hinnites gigantea Gray), and other shells not elsewhere found abundantly. The bay is protected on the southwest by a low, narrow peninsula, with a hard, sandy ocean beach, and sand or mud on the bay side. North of San Diego Bay lies a large lagoon known as False Bay, which possesses extensive muddy flats and a narrow peninsula of sand dunes on the west. Inside of this bar is a stretch of rocky beach, famous as a clam bed, and to this refer-ence is usually made when False Bay is mentioned. North of the ocean side of this peninsula the beach is similar to that on the west of Point Loma, rocky pools with irregular stretches of flat or broken boulders partially imbedded in shell sand, beneath which a rich harvest of small species may be anticipated. Todos Santos (or All Saints) Bay is unprotected from the surf, and on the north and south possesses rocky beaches, between which on the east lies about 20 miles of hard, sandy beach, poor in living shells. The north beach is of a volcanic formation, while on the south it is largely composed of fossil shells, of which there is an immense deposit. When the station is not mentioned, the species has been found at both San Diego and on Todos Santos Bay. The determinations have largel}'^ been made or verified by George W. Try on, jr., of Philadelphia, and William H. Dall, of Washington, to whom I am greatly indebted. Specimens of the more interesting species have been contributed to the United States National Museum and the Museum of the Academy of Natural Sciences at Philadelphia. * The specific uomenclatnre of this paper has been revised by Mr. W. H. Dall at Mr. Orcutt's request ; the rarer species have been examined, and several doubtful species have been determined by Mr. Dall from the types in the National Museum. Occasional notes in brackets have also been added by Mr. Dall.
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