i 9 6 



COPEPODA 



inner and an outer longitudinal series were found (PI. VII fig. Qd); the arrangement of hairs between 

 and behind the serrulae was not studied in details. In the middle, between the labial lobes, a large 

 median group of setae was found, which on each lobe is continued into two lateral series placed 

 closely to each other; more laterally, well separated from this system, a lateral row of shorter setae, 

 starting from a basal group, was observed. 



The intestinal tract is anteriorly produced into a rather slender rostral coecal sac; posteriorly 

 the wide stomach is attenuated, and is, somewhat in front of the abdomen, continued through a slight 

 curvature into the straight intestine proper. 



fc?. Size of specimen from Thor St. 180 was 3-84 mm.; anterior division 2-65; urosome 1-19 mm. 



The body is somewhat more slender than in the female, with rounded lateral corners of the 



well marked short fifth somite; the rostral filaments are scarcely different. The urosome is almost half 



as long as the anterior division, and the comparative 

 length of its somites is 23, 40, 34, 44 and 4 (PI. VIII 

 fig. 8c). 



The antennulae scarcely extend to the end of 

 the furca; the number of free segments is scarcely 

 different from that found in S. inagnus, but the seg- 

 ments 13 and 15 are partly fused with the preceding 

 ones, as the articular line is wanting behind; the 

 measurements and the appendages are very much 

 like those of S. globiceps. The antennae and mandi- 

 bitlac are scarcely different from those of S. inngiins. 

 The maxillulac are fairly well developed ; the Le 

 possesses 9 setae; the Li I has at least 8 rather 

 delicate setae, the Li II has 2 setae and the Li III has 4 setae; the third basipodite has 4 setae; and 

 the Ri 2 -j- 5 setae; the exopodite has as in the female 8 setae. The maxillae are fairly developed, 

 with 4 setae in each of the four proximal lobes; the lobe V has one spine somewhat stronger than 

 the corresponding one of the lobe IV; the endopodite has 6 soft sensory setae, but not amalliform ones, 

 the maxillipeds are like those of the male of 6'. magnus, but no setae were observed in the middle of 

 the second basipodite. 



The natatory legs show in all features of interest complete similarity to those of the female. 

 They/?A pair of legs is very characteristic, as seen in text-fig. 61 a; on the right side (PI. VIII 

 fig. 8 c) we have a long and slender first basal segment, followed by a well enlarged second segment. 

 The right endopodite (text-fig. 61 b) is rather short, somewhat clavate, and has a slender, delicate seta 

 almost half as long as the segment; the right exopodite consists of three long slender ones, of which the 

 first is much the longer and thicker, while the third, somewhat plate-shaped one, is the shortest and 

 most slender (text-fig. 61 c). The two basal segments on the left side are, like those of S. -magnus, long 

 and slender; the left exopodite has 3 segments (text-fig. 61 d), of which the third one, which is much 

 the shortest, is distinctly attenuated, with a terminal seta; the left endopodite is long and slender 

 and extends distinctly beyond the end of the exopodite. 



Text-fig. 61. Scapfwcalanus obt^ifrons G. O. Sars f o". 



a. Pes V X 58. b. Pes V dext. Ri X 150. c. Pes V 



dext. Re III X 150. d. Pes V sin. Ri X 150. 



