JIO Mr. E. W. Sexton on LX. — A new Amphipod Species, Tryphosltes alleni. By E. VV. Sexton, Marine Biological Laboratory, Plymouth. [Plate XIV.] Two specimens of the species described below were taken by Dr. Allen during the cruise of the ' Huxley ' in the north of the Bay of Biscay, August 1906, trawled in 246 fathoms, 48° 7' N., 8° 13' W. Fara. Lysianassidse. Genus Tryphosites, G. O. Sars. Tryphosites alleni^ sp. n. (PI. XIV.) Two specimens, ovigerous females, measuring 10 mm. from the tip of the rostrum to the tip of the telson. Besides these two specimens I have been able, through Mr. Tattersall's kindness, to examine some fourteen others, taken, together with the type species, T. longipes, by the ' Helga ' on the west of Ireland, in 200 fathoms. They were of all sizes, measuring from 2*5 mm. to 10 mm. in length ; the four largest were males. With regard to the distribution of tlie two species, Mr. Tattersall has informed me that " T. longipes is alone found in shallow water. The other form is alone found in very deep water, and the two forms together in intermediate depths." Descrij)iion. In general aspect much resembling the type species, T. longipes *, the principal distinguishing characters being found in the hand of gnathopod 2, the shape of side-plate 4, the epimera of pleon-segment 3, and the telson. Head longer tiian the first pera;ou-segment, but not equal to the first two in length; lateral corners mucli produced and acute. Eyes large, a long oval, pigment faded. iSide-plates as in the type species with the exception of side-plate 4 ; in this (fig. 1) the projecting portion of the lower hind margin is rounded, in lo7igipes it is truncate and angular. * A full description and figures will be found in Prof. Sars's ' Crustacea of Norway," vol. i, p. 81, pi. xxyiii. tig. 3, and pi. xxix. fig. 1.