COPEPODS OF THE WOODS HOLE REGION 



375 



gent, with very short apical setae. Second antenna with a stout 

 apical claw; spine on second segment of this antenna furcate; fifth 

 legs two small knobs, each with a single apical seta. Total length, 

 3.25-3.5 mm. 



FiGDRB 229. — Copilia mira'bilis: a, Female, dorsal; 6, male, 

 dorsal ; c, male, fourth leg (after Brady) 



Male. — Head separated from first segment; first and second free 

 segments wider than the head, the rest of the body tapered back- 

 ward; second antenna very slender, the proportionate lengths of its 

 segments as 9:8:5:8; spine on inner margin of second segment 

 falcate and unbranched. Total length, 5.25-5.5 mm. 



Family ERGASILIDAE 



Genus ERGASILUS Nordmann, 1832 



Body cyclopslike, narrowed posteriorly; head sometime^ fused 

 with, sometimes separated from, the first segment; urosome 4-seg- 

 mented in female, 5-segmented in male, one-third as long as meta- 

 some or less; caudal rami short. First antennae 6-segmented; sec- 

 ond antennae 3-segmented, the apical claw greatly enlarged and 

 used for prehension; mouth parts removed some distance behind 

 the second antennae; mandibles setose; maxillipeds entirely lacking 

 in the female, present and strongly developed in the male. Rami of 

 first four pairs of legs 3-segmented, except the fourth exopods, which 

 are sometimes 1- or 2-segmented; fifth legs uniramose, 1-segmented, 

 rarely obsolete. Two ovisacs, eggs small and numerous. Females 

 parasitic on the gills of fish, males free swimmers; found in both 

 fresh and salt water. 



