COPEPODS OF THE WOODS HOLE REGION 497 



transverse grooves. First antennae 1-segmented ; second antennae 

 with a stout apical claw; basal portion of maxilliped a flat lamina 

 as in the female, but the terminal portion is a single flat segment, with 

 an apical fringe of hairs and a large spine at the outer corner. Total 

 length, 0.43 mm. 



Remarks. — This genus can be identified by the presence of only 

 one pair of leg rudiments on the first segment, and a pair of horns at 

 the anterior corners of the head, and by the absence of all paired 

 processes. 



Genus CHONDRACANTHUS La Roche, 1811 



Female. — Head small, separated from the thorax by a more or less 

 clearly defined constriction; first and second segments usually free 

 and narrower than the head and the posterior body; the remaining 

 segments fused with the genital segment into a trunk, indistinctly 

 divided near its center and produced at its posterior corners, and 

 ventrally or laterally, into paired processes. Abdomen very small, 1- 

 or 2-segmented ; no caudal rami. First antennae usually fleshy ; sec- 

 ond antennae prehensile; mouth parts removed to the posterior 

 margin of the head; mandibles falciform; end segment of maxilla 

 spinelike, toothed on its outer margin; two pairs of biramose legs, 

 rami very rudimentary. 



Male. — Head more or less fused with first segment and much 

 larger than the rest of the body; second segment free and carrjdng 

 the second pair of legs; trunk 4-segmented; caudal rami well de- 

 veloped, conical; two pairs of uniramose, 1-segmented legs, each 

 ramus cylindrical with two apical setae, sometimes laminate with 

 an anterior process. 



KEY TO THE SPECIES (FEMALES) 



1. Head much wider than long, posterior corners smoothly rounded ; 



third segment processes invisible dorsally cottunculi (p. 497) 



Head much longer than wide, with short, fleshy horns at pos- 

 terior corners ; third segment processes visible dorsally m.erlucii (p. 498) 



CHONDRACANTHUS COTTUNCULI Kathbun 



FiGUEE 297, c 



Chondracanthus cottunculi Rathbun, Proc. U. S. Nat. Mus., vol. 9, p. 322, pi. 

 11, 1886. 



Occurrence. — Taken from the gill cavity of two deep sea sculpins 

 {Gottunculus thom^sonii and C. microps) by Rathbun off Georges 

 Bank in 1883. 



DistHhution. — Not found outside the present area. 



Color (preserved material). — Body yellowish white or light flesh 

 color, the oviducts a dull yellow. 



