22 



Gen. 5. SpmOCalanUS, Giesbrecht, 1892. 



Generic Characters. Body comparatively short, with the urosome not 

 nearly so elongated as in Pseudocalanus. Front quite unarmed, without any 

 tentacular filaments below. Anterior antennae longer than the body, and very 

 flexible ; those in male transformed in a manner similar to that in Pseudocalanus. 

 Posterior antennae with both rami rather produced, the outer one being the longer. 

 Posterior maxillipeds unusually slender, with the terminal part much elongated 

 and armed distally with coarsely ciliated procurved setae. Legs very slender, 

 inner ram us of 2nd to 4th pairs densely spinulose on the hind face. Last pair 

 of legs wanting in female, in male of comparatively small size, right leg not 

 sty li form. 



Remarks. This genus was established in the year ]892 by Dr. Giesbrecht, 

 to include a small Calanoid procured from very great depths in the tropical part 

 of the Pacific. The genus differs from Pseudocalanus chiefly in the total absence 

 of the usual tentacular filaments at the front, the less slender urosome, the very 

 long anterior antennae, the peculiar shape of the posterior maxillipeds, and finally 

 in the spiny armature of the inner ramus of the 2nd to 4th pairs of legs. In 

 the northern ocean this genus is represented by a species closely allied to the 

 typical one, and first described by the present author from Nansen's Polar Ex- 

 pedition. This species has proved also to belong to the fauna of Norway. 



7. Spinocalanus longieornis, G. 0. Sars. 



(PI. XII). 



Spinocalanus longicornis, G. 0. Sars, The Norwegian North Polar Expedition. V. Crustacea, p. 75, 



PL XXII. 



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

 oblong oval, greatest width somewhat exceeding Vs of the length, front obtusely 

 rounded ; seen laterally, evenly vaulted above, with the front narrowly produced 

 and without any trace of a rostrum or tentacular filaments below. Lateral corners 

 of last segment of metasonie obtusely rounded off. Urosome scarcely exceeding 

 in length y 4 of the anterior division, genital segment comparatively short and 

 greatly protuberant below; caudal rami very short, being scarcely longer than 

 they are broad, apical setae about as in Pseudocalanus. Anterior antennae exceed- 

 ing the body by about Vs of their length, penultimate joint provided in front 

 with an unusually long and slender bristle. Posterior maxillipeds with the 2nd 

 joint of the terminal part fully as long as the 3 succeeding joints combined. 



