27 



Gen. 7. ChirldlUS, Giesbrecht, 1892. 



Syn: Euchceta, Boeck (part.) 



Generic Characters. Cephalosome but slightly vaulted in front, rostral 

 projection very small, bifid, or wholly absent. Last segment of metasome pro- 

 duced behind on each side to a more or less developed spiniform process. Uro- 

 some about as in JEtideus but with the genital segment in female less protuberant 

 below. Caudal rami very short, with the appendicular bristle not prolonged, and 

 proceeding from the lower face of the rami. Eye comparatively large, and placed 

 less ventrally than in jEtideus. Anterior antennse much shorter than the body, 

 but rather slender, and resembling in structure those in the above-named genus. 

 Posterior antennse with the outer ramus much longer than the inner. Mandibles in 

 female with the masticatory part very largely developed, inner ramus of the palp, 

 however, unusually small. Masticatory parts of mandibles and maxillae in male 

 quite rudimentary. Anterior maxillipeds in female normal, in male much reduced. 

 Posterior maxillipeds with the 2nd basal joint long and slender, terminal part 

 comparatively short and reflexed. Natatory legs of a structure similar to that in 

 JEtideus. Both legs of last pair in male well developed, 5-articulate, the right 

 one being the stronger, 2nd joint in each leg sometimes with a small appendage 

 inside (rudiment of an inner ramus). 



Remarks. This genus was established by Dr. Giesbrecht in the year 

 1892, to include a Mediterranean species, C. Poppei, which, however, is rather 

 imperfectly figured. In the year 1900, I was able to state that this genus is well 

 represented also in the northern ocean, 3 different species having been described 

 from Nansen's Polar Expedition, one of them being at that time considered to be 

 identical with Boeck's Euchceta armata. The genus is closely allied to JEtideus, 

 from which it differs, however, in the far less developed rostrum, the different 

 shape of the cephalosome, and partly also in the structure of the posterior an- 

 tennse, mandibles and posterior maxillipeds. Finally, both legs of the last pair 

 in the male are well developed. 3 species, to be described below, belong to the 

 Norwegian fauna. 



9 Chiridius armatus, (Boeck). 



(PI. XV & XVI.) 



Euchceta armata, Boeck, Nye Slsegter og Arter af Saltvands-Copepoder. Christ, Vid. Selsk. 



Porhandl. p. 39. 



Specific Characters. Female. Anterior division of body somewhat tumid, 

 seen dorsally, oblong oval in form, anterior extremity slightly contracted, but 



