no.1654. AMPHIPODA FROM WEST VORTR AMERICA HOLMES. 508 



tively much shorter carpus. Ii differs From Onisimtu also in not 

 having the infero-posterior angle of the third abdominal segment 



produced into an acute tooth, and IV /'■-> udalibrotus in it- shorter 



antennae, in the position of the mandibular pulp, and in having the 

 upper lip clearly defined from the epistome. From Lysiana 

 which it resembles, it differs in having two setae on the inner plate of 

 the fir>t maxillae, in having simple gills, and in having the first 

 gnathopods subchelate. From Aruga it differs in the last named 

 character and in the simple e;ill-. From Lysianopsis it differs in the 

 subchelate gnathopods and the terminal uropods. 



KOROGA MEGALOPS. new species. 



Lateral lohes of head broadly rounded. Eyes very Large, elongated, 

 nearly meeting above. First antenna' with the fiagellum about as 

 long as the peduncle and composed of one elongated joint and about 

 seven others: secondary fiagellum about two-thirds as long a- the 

 primary and composed of four joints. Second antennae \\ ith the last 

 basal joint a little shorter than the preceding one: fiagellum shorter 

 than the peduncle and composed of about twelve joint-. 



Epistome earinate in front, very slightly convex. Lower lip evenly 

 rounded in front. Mandibles with the molar low. more or less pointed 

 behind and covered with short -eta 1 . Distal margin of second ex- 

 panded joint of the palp of the first maxillae furnished with seven 

 spine-teeth external to which are a few small serrations. Inner 

 plate-, of maxillipeds narrow, distally truncated, furnished with 

 plumose -eta- on inner side: outer plate with about fourteen small 

 denticulations and two very -mall -pine- on distal margin. 



First gnathopods with the very short carpus furnished with a 

 narrow posterior lobe closely applied to the base of the hand: hand 

 quadrate, nearly as broad as long; palm transverse, about a- long 

 as the slightly concave posterior margin ami armed with a -pine at 

 the end. evenly and gently convex and cut into several minute, sharp, 

 irregular serrations. Second gnathopods with the lower posterior 

 part of the elongated and distally widened carpus bulging and 

 scabrous; hand twice as long as wide, slightly widening distally. 

 First and second peraeopods with the mem- widened and produced 

 at the antero-distal angle. 



[nfero-posterior angle of the third abdominal segment a right 

 angle. The posterior extremity of the dorsal side of this segment 

 curves abruptly downward and overhangs a dorsal depression on the 

 fourth segment, which i- followed by an elevation ending abruptly 

 near the posterior margin. Third uropods extending farther hack 



than the other-, the rami a little longer than the peduncle, the outer 

 ramus .somewhat the longer. Telson tapering to a notched extremity 



