NO. 1573. PARASITIC COPEPODS— WILSON. 449 



The carapace has broad posterior lobes; the genital segment is 

 enlarged and shows a pair of sixth legs at its posterior corners, and 

 a pair of fifth legs just in front of the corners on the lateral margins; 

 the abdomen is two-jointed, the joints equal; the antenme and 

 mouth parts are like those of the female hicolor, and the rami of 

 the swimming legs are all two-jointed. 



NOGAGUS BOREALIS Steenstrup and Liitken. 



Nogagus borealis .STEENSTRur and Lutren, 18(il, p. .387, pi. xi, lig. 21. 



This species was first described by the above authors from five 

 specimens, three of which had been taken on a voyage to the West 

 Indies and the other two on a voyage to Greenland, the exact locali- 

 ties being given for the latter only. They show the following char- 

 acteristics: Carapace oval, considerably less than half the entire 

 length, with short and narrow posterior lobes; three free segments 

 diminishing regularly in width, but about the same length; genital 

 segment rectangular, twice as long as wide, with two longitudinal 

 furrows on both dorsal and ventral surfaces. 



Abdomen one-jointed, anal laminae short and very wide. First 

 antennjs with long and bushy setse; first maxillipeds with stout 

 terminal claw and small accessory claw, both armed with short hairs, 

 and with a small bunch of hairs between their bases. Rami of the 

 first three pairs of legs two-jointed, of the fourth pair one-jointed. 

 These characters are the same as those of the single specimen de- 

 scribed on page 437 and warrant the placing of this species under the 

 genus Nesippus. 



ECHTHROGALEUS BRACCATUS (Nogaus male) Heller. 



Echthrogakits braccains Heller, 1865, p. 197, pi. xx, lig. 3. 

 A male Echthrogaleus (see p. 366). 



NOGAGUS BREVICAUDATUS Milne Edwards. 



Nogagus brevicaudatus Milne Edwards, 1840, p. 460. 



Milne Edwards has given us the only description ever published 

 of this species, a short and very incomplete one, as follows: "Espece 

 tres voisine du Nogague grele (A^. gracilis), mais ay ant I'abdomen 

 plus court et compose d'une seule piece subtriangulaire. Trouve aux 

 environs de Teneriffe." 



There are no figures with this description, and thus wliile it is 

 probable that the species is identical with Steenstrup and Liitken's 

 Nogagus tenax, as those authors suggest, there is no possible way 

 to prove this, and we must wait for further data before becoming 

 able to locate it definitely. 



Proc. N. M. vol. xxxiii— 07 29 



