25 



terised, was accepted by Dr. Giesbrecht, who describes a form from the Mediter- 

 ranean, which he regards as identical with Brady's species, though in some 

 respects it seems to differ rather conspicuously. Neither of these authors was 

 aware that a very similar form was recorded many years ago from the Norwegian 

 coast by Boeck, who applied to it the very same specific name as that proposed 

 by Brady. The validity of these 3 forms as distinct species is perhaps still somewhat 

 questionable, the similarity of the Norwegian form with that described by Brady 

 being in particular so very close, that I should have been much inclined to 

 regard the two as identical, if the widely remote occurrence of these 2 forms 

 did not seem to forbid such an identification. The genus is easily recognized, 

 at any rate in the female sex, by the very strong and highly chitinized bifurcate 

 rostrum, the boldly vaulted cephalosome, and the coarse mucroniform projections 

 of the last segment of the metasome. 



8. >tideus armatus, Boeck. 



(PI. XIII & XIV.) 



Psewlocalanus armatus, Boeck. Xye Slsegter og Avter af Saltvands Copspoder. Christiania 



Vicl. Selsk. Forhamll. 1872, pag. 6. 



Specific Characters. Female. Anterior division of body, seen dorsally, 

 oval fusiform, greatest width considerably exceeding Vs of the length and occurring 

 in the middle, anterior extremity more narrowed than the posterior, and pro- 

 jecting somewhat between the insertions of the anterior antennae; seen laterally, 

 strongly vaulted in front, with the dorsal margin of cephalosome forming a bold 

 and continuous curve ^up to the tip of the rostrum, the latter scarcely incrassated 

 at the base, rarni sharply pointed and separated by an even emargination. Lateral 

 corners of last segment of metasome gradually exsertecl to strong mucroniform 

 processes pointing straight behind, and reaching about to the end of the genital 

 segment. Urosome scarcely exceeding in length Vs f the anterior division, 

 genital segment comparatively short and rather dilated in the middle. Caudal 

 rami considerably longer than the anal segment, sublinear, finely ciliated inside, 

 innermost but one of the apical seise much longer than the others. Anterior 

 antennae, when reflexed, reaching to about the base of the caudal rami. 



Male considerably smaller than female, and of much more slender form 

 of body, front narrowly rounded and quite unarmed; posterior projections of last 

 pedigerous segment far less developed than in female. Urosome exceedingly nar- 

 row, and exceeding in length Vs of the anterior division; caudal rami generally 

 spread to each side. Anterior antennae, when reflexed, scarcely reaching to the 



4 Crustacea. 



