508 BULLETIN 15 8, UNITED STATES NATIONAL MUSEUM 



with three or four spines, the endopods are spatulate and unarmed, 

 the two rami are about the same length. Total length, 0.45-0.5 mm. 

 Remarks. — The hosts of this parasite are deep-sea fishes that fre- 

 quent the continental slope at the southern end of the present area, 

 and in every instance only a single female with attached male was ob- 

 tained from each host. The female can be recognized by the deflec- 

 tion of the head and the three pairs of clavate processes, the male by 

 the second antennae and the swimming legs. 



CHONDRACANTHOPSIS, new genus 



FemMe. — Head separated from the first segment and much wider 

 than long; first two thoracic segments distinctly separated, the rest 

 of the thorax completely fused and armed with a row of rounded 

 knobs along each lateral margin, and a row of transverse laminae 

 down the midline of the dorsal surface. These laminae are semi- 

 lunar and are folded back against the dorsal surface of the thorax; 

 urosome small, 2-segmented. First antennae 1-segmented; second 

 antennae with stout apical claws; mandibles falcate, toothed on both 

 edges; maxillae spiniform, toothed on the outer margin; maxillipeds 

 2-segmented, uncinate. Two pairs of uniramose legs, each made up 

 of a winged basal segment and a boot-shaped distal segment. Ovi- 

 sacs cylindrical, longer than the body. 



Male. — Head fused with the first two thoracic segments, both 

 pairs of antennae at the extreme anterior end, which is somewhat 

 pointed ; trunk 3-segmented ; caudal rami slender, conical, each end- 

 ing in a small cilium. Mouth parts like those of the female; two 

 pairs of uniramose legs, each made up of a swollen lamina, with two 

 minute apical setae. 



Genotype. — ChTondracantho'psis nodosus (Miiller). 



Remarks. — This new genus is established for the species Chondra- 

 canthus nodosus of Kr0yer, and to it possibl}'- belongs also Scott's 

 species ornatus., but we know nothing about the swimming legs of 

 this latter species, and they are the chief characteristic of the present 

 genus. The species has never before been reported from this side of 

 the Atlantic, although it is common around the British Isles. 



CHONDRACANTHOPSIS NODOSUS (Muller) 



Plate 39 



Lernaea nodosa O. F. Muller, Zoologia Danica. p. 40, pi. 33, fig. 5, 1779. 

 Chondracantluis nodosus T. and A. Scott, The British parasitic Copepoda, 

 p. 17G, pi. 48, figs. 13-16 ; pi. 52, figs. 1-3, 1913. 



Occurrence. — Taken from the gills of the common redfish {Sehas- 

 tes maHnu-s), captured at three different localities north and east of 

 Cape Cod in 1878. 



