NO. 1507 



FRESH-WATER AMPHIPODA— W ECKEL. 



39 



the posterior one furnished with three or four small fascicles of hairs; 

 palm oblique, with two emarginations, and furnished with a few long 

 hairs and a group of six or eight spines at the posterior angle; dactyl 

 strongly curved, as long as the palm. 



Carpus in the second gnathopods more elongated than in the first 

 pair; propodus oblong; lateral margins only slightly curved, the pos- 

 terior one furnished with six oi seven fascicles of long hairs; palm 

 less oblique than in the tirst pair, furnished with a row of long hairs 

 at the base of the lamellar edge and six or seven spines at the rounded 

 posterior angle; dactyl not so strongly curved as in the tirst pair, 

 longer than the palm. 



Fig. 7.— Gammaki's eamellus, male. Point Arena, California, m., mandible, drawn to a 



LARGER SCALE THAN THE OTHER PARTS; Ob. d., DORSAL SIDE OF THE LAST SEGMENTS OF THE 

 ABDOMEN. 



Coxal plates of the last three peraeopods with the posterior margins 

 serrated and furnished with short spines. 



Postero-lateral angles of the first three abdominal segments pro- 

 duced but little and terminating in a small spine. The last three or four 

 abdominal segments are furnished dorsally on each side with a fascicle 

 of two or three spines and a few short hairs. 



First uropods projecting backward slightly beyond the peduncle 

 of the third pair; third pair with the peduncle short, as broad as long, 

 armed distally with a few hairs; outer ramus elongated, biarticulate, 

 the basal segment long, tapering distally, armed laterally with fasci- 

 cles of a few long hairs and one or two large spines; terminal segment 

 ver}^ short, tapering distally and terminating in a tuft of long hairs; 

 inner ramus rudimentary, slightly more than half as long as the 



