36 AMPHIPODA NORMALTA. 



the animal ; pcdiiiKlc scarcely half the length of the antennae. 

 The gnathopoda small, the anterior being somewhat the larger. 

 Length ^ths of an inch. 



This species bears a close resemblance generally to A. Nilssonii, but 

 differs from it in the greater relative length of the lower antennae 

 and in the form of the gnathopoda, and in the rare circumstance of 

 the anterior being larger than the second. The palms are convex. 



The figure is probably that of a female, which may account for the 

 smallness of the second paii' of gnathopoda. 



It was taken on the coast of Piedmont by J. Gwya Jeffreys, Esq. 



2, Allorchestes Ochotensis. (Plate I. a. fig. 4.) 

 Allorchestes Ochotensis, Brandt, Middendorfs Reise, pi. 6. f. 27. 



Male. — Eyes small and round. Upper antennae nearly as long as the 

 lower. Gnathopoda not very largely developed, the second being 

 the larger ; palms straight. The three anterior segments of the 

 pleon posteriorly and dorsally developed into teeth. 



Length nearly an inch. 

 Hah. Ochotsk. 



3. Allorchestes Knickerhockeri, n. s. (Plate VI. fig. 1.) B.M. 



Female. — The animal is compressed. The first and second segments 

 of the pleon posteriorly and dorsally produced into a tooth. Eyes 

 oval, not large. Superior antennae nearly as long as the inferior, 

 having the peduncle and flagellum nearly equal in length. Infe- 

 rior antennae one-thii'd the length of the animal, and one-fourth 

 longer than the superior ; the last two articulations of the pedun- 

 cle are equal ; the flagellum is not longer than a single articu- 

 lation of the pedimcle ; the articulations of the flagella of the 

 antennae three times their diameter in length. First pair of 

 gnathopoda small and slender; the propodos is very long; the 

 palm is produced forwards, and terminates in an obtuse point ; 

 the dactylos is short, and scarcely reaches to the extremity of 

 the propodos ; the cai'pus is nearly as long as the propodos, the 

 inferior carpal process not much produced ; meros broader than 

 the carpus. Second pair of gnathopoda considerably larger than 

 the first ; the propodos is triangular ; the palm is slightly convex, 

 and has a notch near the inferior extremity to receive the point 

 of the dactylos ; carpus but slightly produced inferiorly. The 

 three posterior pereiopoda nearly equal; the posterior margins 

 of the squamiform bases serrated in each. 



Length about ^ths of an inch. 



This animal was sent with a few others by Professor Say to the 



