COPEPODS OF THE WOODS HOLE REGIOlSr 



233 



wide; caudal rami shorter than anal segment, swollen through the 

 middle, the outer margin convex with two stiff spines and three short 

 spinules, the distal end obliquely truncated. First antennae scarcely 

 reaching the center of the cephalic segment; exopod of first legs 

 nearly as long as endopod; endopod of 

 fourth leg scarcely reaching the tip of the 

 basal exopod segment ; distal segment of fifth 

 leg twice as long as wdde, with five setae, the 

 terminal one much longer than the others; 

 basal expansion nearly reaching the tip of 

 the distal segment, with six very unequal 

 setae. Total length, 0.5-0.6 mm. 



Male. — Smaller than the female, with the 

 same proportions ; genital segment completely 

 divided ; the two distal segments of the second 

 endopod fused into a single cone, with one 

 apical and two inner setae; inner process on 

 middle segment of third endopod straight, 

 acuminate, and twice the length of the ter- 

 minal segment ; distant segment of fifth legs 

 as wide as long, with six setae, basal expan- 

 sion much reduced and tipped with two sub- 

 equal setae. Total length, 0.4-0.5 mm. 



Remarks. — This species may be recognized by its small size and 

 short first antennae, and it differs from all known species in the bifid 

 tips of the spinules on the anal operculum. It lives in wet moss at 

 or just above the water's edge and clings to the moss so tenaciously 

 that it can be obtained only by picking it off with forceps under a 

 binocular. 



Figure 156. — Canthooamp- 

 tus minutun: a, Male, 

 dorsal ; b, female, fifth leg 



Genus ATTHEYELLA Brady, 1880 



Body slender and cylindrical, metasome scarcely wider than uro- 

 some ; head fused with the first segment and a little shorter than the 

 rest of the metasome; urosome 4-segmented in female, 5-segmented 

 in male, passing insensibly into metasome anteriorly, tapered pos- 

 teriorly; caudal rami much longer than wide. First antennae 8- 

 segmented, geniculate in the male; exopod of second antennae 1- 

 segmented and minute ; first legs subprehensile, exopod 3-.segmented, 

 endopod usually 2-segmented, but rarely 3-segmented ; exopods of the 

 three following pairs of legs 3-segniented, endopods 2-segmented, dis- 

 tal segment much longer than basal ; third endopods transformed in 

 male; fifth legs 2-segmented, of the usual pattern. One species 

 found here. 



