having the peduncle longer than the peduncle of the superior. Mandibles having an appendage. Maxillipeds unguiculate, having a small squamous plate to the coxa, basos, and ischium. Gnathopoda uniform, each having the propodos large, with the postero-inferior margin posteriorly produced; carpus attached to the propodos near the centre of its superior margin; infero-anterior margin produced along the inferior margin of the propodos. Pereiopoda slender, subequal. Posterior pair of pleopoda biramous. Telson long, narrow, cleft at the apex.” 1. E. cuspidatus, Kröyer, var. antarcticus, G. M. Thomson (Ann. & Mag. N.H., ser. V., vol. VI., p. 4). Pleon having the first two segments produced backwards on their postero-dorsal margins into teeth; fourth segment with a central dorsal sinus. (Two posterior segments of the pereion smooth, not produced into teeth.) Eyes reniform. Superior antennæ scarcely half as long as the animal; peduncle shorter than flagellum; flagellum minutely articulated, every third articulation produced downwards into a tubercle and furnished with a tuft of cilia; secondary appendage uni-articulate, almost obsolete. Inferior antennæ scarcely as long as the superior, having the peduncle much longer than the peduncle of the superior; flagellum scarcely longer than the last joint of the peduncle. Both pairs of gnathopoda having the carpus attached near the centre of the superior margin of the propodos, and produced along the inferior margin as far as the palm; propodos subquadrate; palm defined by a double row of hairs, which are alternately very short, point of impingement of the dactylos defined by a fascicle of short stout spines. Penultimate pair of pleopoda shorter than the preceding; ultimate reaching rather beyond the ante-penultimate. Telson long, narrow, grooved longitudinally, and cleft at the apex. Length, .35 inches. (The Greenland species is 1.25 inches long.) Genus Aora, Kröyer. (Brit. Mus. Cat. Amphip. Crust., p. 160.) Superior antennæ longer than the inferior, and carrying a secondary appendage. Inferior antennæ having the peduncle much longer than the flagellum. First pair of gnathopoda much longer than the second, and having the meros produced inferiorly into a long tooth. Third pair of pereiopoda shorter than the first two, fourth much longer than the third, fifth much longer than the fourth. Posterior pair of pleopoda biramous. Telson tubular. 1. A. typica, Kröyer. Lalaria longitarsis, Nicolet, Gay's Hist, de Chile. Body smooth, eye small, black, and round. Superior antennæ nearly as long as animal; flagellum twice as long as peduncle; secondary