Xorth Aiitvricdii ('ciifrojKn/idc'. 239 



Limnocalanns mncrurus, tie Giieriie et Richard, '89b. p. 77. PI. IV^., 



Fis- 5. 11, 12. 

 Limnocalanus marrin-»ts anctus. Forbes, "90. p. 6-lS. 

 Limnocalanus macrwus. Marsh, '93. p. 201, PI. IV., Fi^;. 7. 

 Linmocahmus marriinis. Marsh. ''.)'•>. ]^. 11, PI. IV., Fi^j. 1, 2; PJ. V., 



Fi-. 1-5. 

 TJnmocalanxs mafmrus. Ilorrick and Turner, "95. p. 49, PI. I.,Fi»;". 1— I. 

 Limnocalanus <jrhnahlii. S.-irs, "97. p. 39, PI. IV., Fig. 1-1 S. 



Body slender. 'I'liorax rather more tliaii one fonrtli as 

 hroad as lonp;, and composed of six well-defined segments, 

 of wliieli the first (constricted at about the middle and armed 

 at the front with two hook-like processes pointing forward 

 and downward) is the longest — about e(jual to the three suc- 

 ceeding segments taken together ; third and fourth segments 

 subequal, together slightly longer than the second, which is 

 armed on the dorsal and latfral surfaces, near the distal end, 

 with a row of rather stout spines ; fifth segment somewhat 

 longer than the last, which is not produced laterally, ])ut 

 armed o\\ each side with a very small spine. Al)domen of 

 female composed of four segments, the first about a third 

 longer than either of the two succeeding segments, which are 

 subequal. Furcal rami about a fifth longer than the first 

 segment, and slightly shorter than the second and third seg- 

 ments taken together ; sparsely provided on the dorsal sur- 

 face with short sharp spines, and on the inner margin with 

 spines and hairs; one plumose seta on the outer margin at 

 the beginning of the distal fifth; and four plumose apical 

 setirTe and a delicate smooth seta on the dorsal surface near 

 the inner ax>ical angle. In the male the first and fourth 

 abdominal segments are subequal, each about a fourth longer 

 than the fifth, which is the shortest; second and third seg- 

 ments subequal, each about twice as long as the fifth ; second, 

 third, and fourth segments armed like the second abdominal 

 segment of the female. Furcal rami proportioned about as 

 in the female and similarly armed. 



Antennse 25-segmented ; right male antenna geniculate 

 between the iHth and 19th segments. The armature of the 

 segments is as follows: 1 and 10 have a short seta and two 

 sense-hairs ; 2, a short seta and three sense-hairs ; 3, a short 



