PUGET SOUND CRUSTACEA. 211 



from the Sooloo Sea, is perhaps the one most closely approaching 

 ours. It differs, however, in the much longer accessory flagel- 

 lum of the upper antenna, the shorter and broader hand of the 

 second gnathopods, and the greater hairiness of body and limbs. 

 Having in view the great difficulty of recognizing with cer- 

 tainty many of the species indicated by the older authors in the 

 difficult group of Amphipoda to which this form belongs, we 

 have judged it best to give a new name to the species described 

 by us, for convenience of reference, at least until it can be shown 

 to be identical with some of the earlier species. 



PODOCERID.E. 



Amphithoe humeralis Stimpson. 



AiupJiitlio'c Jiiinicralis Stimpson, Proc. Acad. Nat. Sci., Phila- 

 delphia, 1864, p. 156. 



Description. — Body rather compressed. Lateral lobes of 

 head very little prominent, rounded. Anterior pairs of coxal 

 plates about equal in depth to the corresponding segments ; 

 fourth pair large, quadrangular, the posterior lobe small and 

 rounded. Eyes small, rounded, close to lateral lobes of cepha- 

 lon, pigment dark. Superior antennae more than half the length 

 of the body ; first joint of peduncle stout, about equal in length 

 to the head and to the rather more slender second joint ; third 

 joint very small, about one quarter the length of the preceding, 

 and much narrower ; flagellum two and a-half times the length 

 of peduncle. Inferior antennae stout, more than half the length 

 of the superior, last joint of peduncle a little shorter than the 

 preceding, flagellum a little more than half the length of peduncle. 

 Lower lip having the posterior cornu of outer lobe large. Palp 

 of mandible having last joint longer than the preceding, not ex- 

 panded. Outer lobe of second maxilla broader, but scarcely 

 longer than the inner. Palp of maxillipeds having the first joint 

 slightly produced exteriorly w^here it forms a distinct shoulder 

 tipped with a tuft of long setae ; outer plates hardly reaching 

 beyond second joint of palp. Gnathopods similar in the two 



