COPEPODS OF THE WOODS HOLE EEGION 517 



First antennae 3-segmented ; second antennae with 1-segmented 

 endopod and 2-segmented exopod; first maxilla tripartite, the outer 

 ramus the shortest ; second maxillae so reduced as to bring the bulla 

 apparently onto the surface of the trunk; basal segment of maxilli- 

 peds armed on its inner margin with knobs and processes. Length 

 of cephalothorax, 4.5-5 mm, ; of trunk, 3-3.25 mm. ; of ovisacs, 

 5-6 mm. 



Male. — Body laterally compressed and anteriorly truncated, with 

 all the appendages and the genital process crowded along the frontal 

 margin. First antennae 4-segmented, basal segment the largest; 

 exopod of second antenna tipped with a tuft of short setae, endopod 

 unarmed ; second maxillae large and stout, with a long terminal claw. 

 Total length, 1.15 mm. 



Genus CLAVELLISA Wilson, 1915 



Female. — Cephalothorax much longer than trunk, often wrinkled 

 and attached to the center of the dorsal surface of the latter; head 

 separated from the neck, with a carapace. Trunk wider than long, 

 depressed ; no genital or posterior processes, abdomen, or caudal rami. 

 First antennae stout and heavily armed; second antennae biramose; 

 first maxillae bipartite or tripartite, with a palp; second maxillae 

 flat and laminate, fused or separate, and apparently attached to the 

 anterior end of the trunk, some distance in front of the base of the 

 neck. 



Male. — Head folded ventrally onto the trunk and the two com- 

 pletely fused, with no distinction of parts, but with a dorsal cara- 

 pace; body ovoid, pointed anteriorly, the antennae, mouth tube, and 

 mouth parts on the ventral surface; genital process curved ventrally 

 and projecting just behind the mouth parts. First antennae 3-seg- 

 mented; second antennae biramose, rami 1-segmented; first maxillae 

 tripartite, with a palp ; second maxillae and maxillipeds with strong 

 apical claws. 



KEY TO THE SPECIES (FEMALES) 



1. Ovisacs at an angle of 45° with trunk axis and attached by one 



side, not by end spinosa (p. 517) 



Ovisacs parallel with trunk axis and attached in ordinary man- 

 ner by their ends cordata (p. 518) 



CLAVELLISA SPINOSA WUson 



FlGUEE 306 



ClaveUisa spinosa Wilson, Proe. U, S. Nat. Mus., vol. 47, p. 694, pis. 50, 52, 1915. 



Occurrence. — Taken from the gills of the common menhaden {Bre- 

 voortia tyrannus) at Woods Hole by M. T. Thompson. 

 Distribution. — Beaufort, N. C. (Wilson). 



