387 



projection, Ist segment of urosome having posteriorly a similar dorsal pro- 

 jection, in front of wliicli there is a deep saddle-shaped depression. Cephalon 

 much dejjressed, and produced in front to a very large horizontally projected 

 spatulate lamella, broadly truncated at the tip, and reaching beyond the 

 2nd peduncular joint of the superior antennae, the lateral edges of the lamella 

 being continued behind, on each side of the cephalon, as a distinct longitiidinal 

 ridge. Coxal plates extremely small and non-contiguous, increasing somewhat 

 in size to the 5th pair, which are the largest and, like the succeeding 

 pair, slightl}' bilobular, being fully twice as broad as they are deep; 4th 

 pair not differing at all in shape from the 3rd. Last pair of epimeral plates 

 of metasome much narrower, and also les.s deep, than the preceding pair, 

 lateral corners evenly rounded. Eyes quite rudimentary, and rejtlaced, on 

 each side, by an irregular patch of a reddish pigment, without any traces 

 of visual elements, but partly coated with a chalky white siibstance. Supe- 

 rior antennas nearly half as long as the body, 1st joint of the peduncle much 

 the largest and rather broad, though not attaining the length of the other 

 2 combined, 3rd joint scarcely more than half as long as the 2nd, flagellum 

 ver}' slender, more than 3 times as long as the peduncle, and composed ef 

 about 24 articulations, the 1st of which is much the largest and provided 

 anteriorly with 4 fascicles of delicate sensory bristles. Inferior antennae con- 

 siderably shorter than the superior, the last 2 joints of the peduncle nearly 

 equal-sized, flagellum aboiit twice the length of the peduncle. Gnathopoda 

 very small and exactlj^ alike, propodos simple cylindric, somewhat curved, 

 and about same length as the carpus, dactylus strong, hook-.shaped. The 2 

 anterior pairs of pereiopoda somewhat larger than the gnathopoda, exhibiting 

 otherwise a rather similar a.spect, though the mutual relation of the meral 

 and carpal joints is, as u-sual, somewhat different, basal joint of both pairs 

 rather broad, sublaminar. The 3 posterior pairs of pereiopoda comparatively 

 more slender and rapidly increasing in length, the last pair being rather elon- 

 gated, with the basal joint considerably expanded and rounded oval in form. 

 Last pair of uropoda with the rami nearly equal-sized, both being lanceolate 

 compressed and terminating in a sharp point. Telson nearly semicircular, 

 being about as long as it is broad at the base, edges evenly curved throughout. 

 Coloiir whitish, withoiit any perceptible pigmentary ornamentation. Length 

 of adult female 8 mm. 



liemarlcs. — The most prominent external characteristic of this remark- 

 able Amphipod, is unquestionably the peculiar spatiilate frontal plate 

 covering the bases of the antennae. It is thereby easily recognizable from 

 any other of the hitherto known northern Amphipoda, though Luphydius 

 sfurionis is the form that comes nearest to it also in this respect. 



