476 BULLETIlsr 15 8, UNITED STATES NATIONAL MUSEUM 



PSEUDOCYCNUS BUCCATUS Wilson 



Figure 285, b 



Pseudocycnus huccatus Wilson, Proc. U. S. Nat. Mus. vol. 60, art. 5, p. 79, 

 pis. 12, 13, figs. 97-103, 1922. 



Occurrence. — Found on the gills of the cero {Scoviberomorus 

 cavalla) , July, 1887, and on the gills of the Spanish mackerel {Scom- 

 heromorus maculatus) ^ August, 1900, the fish hosts captured in the 

 nets on Marthas Vineyard. 



Distribution. — Not found outside the present area. 



Color. — Body a light flesh red, oviducts dark brown; prehensile 

 claws yellow tipped with dark red; ovisacs brown deepening in 

 color with development. 



Female. — Carapace obovate, considerably widened anteriorly and 

 narrowed posteriorly, where it is divided into two lobes by a narrow 

 median sinus. Second segment not quite so wide as the head, nar- 

 rowed anteriorly and widest across the posterior margin. Third 

 segment wider and shorter than the second ; fourth, fifth, and genital 

 segments fused into a trunk five times as long as wide ; egg strings as 

 long as the trunk and one-third its diameter. Abdomen half the 

 diameter of the trunk, 1-segmented ; caudal rami short and conical, 

 each tipped with a single seta. First antenna indistinctly 3-seg- 

 niented; terminal claw of second antenna with an accessory spine 

 on its inner margin near the center, and another at the base. Basal 

 segments of maxillipeds greatly enlarged, terminal claw long and 

 slender. First legs mere knobs; each second leg a bilobed lamina, 

 suggesting two rami ; third leg a short and wide lamina ; fourth leg 

 obsolete. Total length, 4^5 mm. 



Male. — Unknown. 



Remarks. — The small size of this copepod and the peculiar struc- 

 ture of the maxillipeds will serve to identify the species. In the 

 original description the first antennae were said to be 6-segmented 

 through a typographical error. 



Family DICHELESTHIIDAE 



Genus HATSCHEKIA Poche, 1902 



Female. — Head separated from the first segment; the first two 

 thoracic segments more or less free, but often fused with each other ; 

 the remainder of the thorax fused with the genital segment into an 

 elongate trunk. Abdomen short and 1-segmented, or lacking ; caudal 

 rami minute. First antennae filiform, 3- to 6-segmented ; second an- 

 tennae with stout apical claws; maxillipeds slender and uncinate. 

 Two pairs of biramose swimming legs, sometimes rudiments of the 



