130 



atlantica, which is said to be the female of sedcniaria; the broad hand, 

 however, separates them. 



It is a remarkable fact, that in all the species of Phronima that have 

 been described, even from widely-separated localities, the variation is 

 very slight indeed. 



ANCHYLONYX, nov. gen. 



Head moderately large, broad and rounded at the top, tapering infe- 

 riorly to the oral apparatus, and excavated in front. Eyes on the lat- 

 eral and dorsal surfaces of the head. Both pairs of antennas present, 

 long; base of the superior pair long and stout, three jointed ; inferior 

 pair slender, four-jointed ; flagellum very attenuated and elongated. 

 Thorax broad, somewhat compressed; segments six. Abdomen narrow. 

 The gnathopoda not subchelate, nor much reduced in size, when com- 

 pared with the following feet; the first and second pairs of thoracic 

 feet long, slender; carpus and meros linear. The third pair enlarged; 

 carpus and meros dilated, with the anterior margin armed with teeth; pro- 

 podus flexes on the carpus, impinging against the teeth on its anterior 

 margin ; dactylus fused with the propodus. The fourth and fifth pairs of 

 feet subequal, shorter than the preceding. The three posterior pairs of 

 abdominal api)endages biramous, lanceolate ; rami pointed. 



This genus is very closely allied to Phronima. It differs only in the 

 character of the antennce, the gnathopoda, and in the less perfectly de- 

 veloped chelce of the third pair of thoracic feet. The shape of the head, 

 the thorax, and the abdomen are almost identical, and there are likewise 

 eye-facets on the dorsal surface of the head. The mandibles are with- 

 out appendages; and the first and second, and the fourth and fifth pairs 

 of thoracic feet are similar to those of the genus above named, as are 

 also the three posterior pairs of abdominal appendages. A pair of 

 wing-like plates exist at the base of the dactylus of both pairs of gna- 

 thopoda. These, I believe, have previously been peculiar to Phronima. 

 The character of the gnathoi^oda and the third pair of thoracic feet 

 allies the genus with Primno; in the structure of its antennae it differs 

 essentially from both. 



Anchylovyx forms a bond of union between the two subfamilies of 

 Bate's — the Phronimides and Phrosimides, which are founded upon 

 the structure of the three posterior pairs of abdominal appendages in 

 the different genera representing the family Phronimid^. In his 

 arrangement he separates Primno from Phronima, which, together, con- 



