The shore waters from the southern peninsula of Alaska down to about Vancouver comprise the Aleutian province. Within this area occur some arctic species, notably the soft-shell clam, /Mya arenaria/, which the fishermen gather in such large quantities for bait along the Maine coast. An increasing number of species common to this west-coast faunal region and to the boreal province of the east coast are being recorded. Some of [pg312] these have been introduced from the East by the agency of man, but others no doubt have a natural range through the icy waters north of America and down through the Bering Sea into the Pacific. THE CALIFORNIAN PROVINCE The Californian province extends from the neighborhood of Vancouver to Cape St. Lucas and has about five hundred species. The northern portion of this area contains some very characteristic forms, together with a good mixture of species of more northern habitat; it might properly be regarded as a subprovince. From San Diego south to the cape the character of the fauna gradually changes; this coast-line of southern California has also been considered a subregion. The main characteristic of the Californian province is a large development of /Haliotis/, of the patelliform mollusks, and of the chitons. A very few minutes on any good collecting-beach of California would convince the Eastern conchologist that he had entered upon an entirely new field of research. The most notable genera are /Calliostoma/, /Chlorostoma/, /Scurria/, /Acmæa/, various genera of the /Chitonidæ/, /Purpura/, /Monoceras/, /Amphissa/, /Norrisia/, /Olivella/, /Chorus/, and /Haliotis/. THE PANAMIC PROVINCE The warmer waters of the Gulf of California belong to the Panamic province, which extends down to South America. This is one of the richest and most interesting faunas in the world. At Panama alone, Mr. C. B. Adams, a noted collector and student of conchology, took upward of four hundred species. About eight hundred species are known in the Gulf of California alone. * * * * * It must be borne in mind that these faunal provinces relate to littoral and shallow-water species, for the present knowledge of deep-water forms is not sufficient to permit of generalization upon their distribution.