Description of a new species of Idotea from Hakodate Bay, Japan

Harriet Richardson
1900 Proceedings of the United States National Museum  
Two distinct species were included by Miers^with Idotea ochotensis Brandt. In a former paper^the author has endeavored to define the limits of Idotea ochotensis on tbe one side by preserving the specific distinctions of Idotea rectilineata Lockington. It is the object of the present paper to further define the limits of Idotea ochotensis on the other side by showing the specific difierences of another species, formerly included. Two specimens from Hakodate Bay, Japan, in the collection in the
more » ... collection in the U. S. National Museum, when compared with a large series of I. ochotensis from various localities, extending all the way from Kamchatka to Bering Sea and the Aleutian Islands, confirms the impossibility of uniting them with I. ochotensis. The specimen which Miers saw in the British Museum collection from Yeddo Island, and which he figures, undoubtedly belongs to the same species as our two specimens from Hakodate Bay. In regard to it Miers says: It differs from Brandt's figure of /. ochotensis only in its relatively longer and slenderer body and somewhat shorter antennse, which when retracted would not reach to the posterior margin of the fourth thoracic segment, hut whose peduncular joints are longer than in Brandt's figure. Further on he speaks of the tooth at the distal extremity of the terminal segment as being very prominent in tbe specimen from Japan. It is probable that Miers had specimens of all three species, the one spoken of obtained at Vancouver Island being /. rectilineata Lockington, the specimen from British Columbia being I. ochotensis Brandt, and the Japanese specimen the one herein described. In comparing the species, specimens have been selected which are of nearly the same size, in order to better compare the corresponding parts.
doi:10.5479/si.00963801.22-1189.131 fatcat:zuldc6ozpnbtxn6at2khqpjiei