﻿COPEPODS FROM LAKE ERH HAI, CHINA — HSIAO 169 



of the abdomen and furcal rami together, slightly asymmetrical, an- 

 terior half of genital segment thicker than the rest, lateral side of 

 swollen portion armed with a hyaline spine, second or preanal segment 

 very short, articulation between this and anal segment distinct; anal 

 segment approximately as long as furcal rami, posterior end slightly 

 wider than anterior, anal sinus shallow; furcal ramus nearly twice 

 as long as wide, left ramus apparently a little longer than right, outer 

 border of both hairless, inner border covered with hair for a greater 

 part of posterior section; caudal setae plumose, well developed, of 

 about equal length, each about half as long as the abdomen. Length 

 of animal from head to end of furcal rami, exclusive of caudal setae, 

 1.04 mm. (fig. 21, «, i). 



First antenna with 25 joints, very long, with last joint reaching 

 end of caudal setae when antenna is folded backward along side of 

 body, last joint with four setae, second with three, ninth, eighteenth, 

 and twenty-second to twenty-fourth with two each, the rest with only 

 one each, aesthetasc on joints 8 and 12, no claw or teeth on terminal 

 joint. 



First pair of swimming legs with one long seta on each basal joint 

 (coxa) of protopodite, arising from a globular, hair-covered protu- 

 berance on the mesial side of distal end; outer surface of both joints 

 of protopodite armed with thick hair, the most distal one of the second 

 joint (basipodite) being thickest; endopodite consisting of two seg- 

 ments only, proximal joint with one seta, distal joint with two mesial, 

 one lateral, and three terminal setae; exopodite consisting of three 

 joints, with two spines on the outer edge, one on proximal and the 

 other on distal joint, proximal and middle joint with one seta on 

 mesial surface, distal joint with three mesial and three terminal setae. 

 The three following legs similar and typical of the subfamily Diap- 

 tominae; Schmeil's appendage present on second joint of the endop- 

 odite of second pair of legs. 



Fifth pair of legs symmetrical, first joint of protopodite larger than 

 second, carrying a stout hyaline spine on outer caudal aspect (fig. 21, 

 h, f) and a hyaline tubercle on medial portion ; second joint of pro- 

 topodite much smaller, carrying a long sensory hair on its outer sur- 

 face; endopodite C3dindrical, without joint, slightly more than half 

 as long as first joint of exopodite, with distal end gently acuminate, 

 carrying on its distal fifth a number of fine hairs; proximal joint of 

 exopodite as long as the whole protopodite, cylindrical, stout, second 

 joint passing distally into a strong curve claw, with dentation on 

 concave surface, claw almost as long as proximal joint, third joint 

 rudimentary, marked by a depression and two short spines, the outer 

 one much smaller, a long seta extending mesial to the longer spine. 



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