300 



PROCEEDINGS OF THE VATIONAL \IV8El 1/. 



vol. 38. 



distal one, one-third to one-half the proximal and bearing two or 

 three setae. 



Second antenna (fig. 2) about one-half as long as first; flagellum 



four-fifths as long as the peduncle and composed of from six to eleven 



segments, each giving off seta? similarly to those of the first antenna; 



peduncle longer or shorter than that of the first antenna 



and furnished with forty to sixty setae, of ten arranged in 



fascicles of three. 



Both pairs of gnathopods similar in the two sexes, the 

 first pair (fig. 3) shorter than the second; propodus 

 longer than broad, the breadth varying from six to 

 seven-tenths of the length, greatest breadth about mid- 

 way between the extremities; palm convex, very oblique, 

 and armed on either side with from ten to thirteen notched 

 spines of unequal length, one near the posterior 

 angle more than twice the length of the others, 

 and near this four or five smaller spines usually 

 crowded together. Between each pair of notched 

 spines are one or two long hairs. The whole 

 margin of palm is closely set with very fine sharp 

 teeth, to be seen with the high-power objective. 

 Dactyl strongly curved, extending to or slightly 

 beyond the posterior extremity of palm and fur- 

 nished with two or three hairs. Posterior margin 

 of propodus straight or slightly convex, with 



eight or ten hail's, some of 

 which are finely plumose. 

 Carpus as broad as long, 

 posterior margin very con- 

 vex, produced slightly and 

 armed with two or three seta' 

 and live or six plumose hairs; 

 anterior 'margin somewhat 

 convex, with one or two long 

 bristles at its distal angle. 

 Basal joint shorter than that 

 of second gnathopod. 

 Second gnathopod (fig. 4) longer than first and differing from it 

 as follows: Basal joint one-fourth to one-third longer than that of 

 fiist gnathopod; propodus one-fifth longer with a larger number 

 of bristles (14 to 18) arranged in fascicles on its posterior margin, its 

 greatest breadth located nearer the proximal end, and hence a more 

 oblique palm. 



Fourth peia'opod slightly longer I ban fifth, which is also longer than 

 the first, second, or third; the third, fourth, anil fifth with spines on 

 both margins of the basal joints, which latter are also deeply and 



3 



I [QS. 1-4. — E. SERRATUS. 1 ANTENNA 1. X '■ DIAM.| ! 

 \.\TK.WA2, X 11 DIAM., 3. QNAtHOPOD 1. \ II IMAM 

 I '.\ ITHOFOD '-', X 1 1 DIAM. 



