COPEPODA 



17 



The body appears more slender than iii the preceding stage; the urosome consists of 2 somites; 

 the Se of fnrcal rami is missing (textfig. 3 a — b). The antennulae, which consist of 23 segments, 

 extend 3 segments beyond the tip of the abdomen. The antennae and other mouthlimbs except the 

 maxillulae, in which the L,e has 8 setae and the Re 8, are scarcely different. The lateral outline of 

 the labrum is as shown in textfig. 3 a alike stage V, but the frontal protuberance is less prominent. 

 The oral surfaces of the labrum and the labium are in their main structures alike f<j>. 



Pes I = St. IV. Pes II in main features alike St. IV, but Ri with 8 setae and Re II <s> III, 

 which is less slender, with 4 Si only (textfig. 3 c). Pes III is comparatively shorter than II, and the 

 Re II <v> III has only 2 Se (fig. 3 d). The pes IV (fig. 3 e) has no seta in basipodite II, 7 setae in 

 unsegmented Ri and 3 Si + 3 rather short Se in Re. The pes V (fig. 3 f) is represented by a wide 

 indistinctly divided basal part, which is distally attenuated, and here subdivided into longer outer 

 branch with at least 3 setae decreasing outwards and a shorter inner branch with 2 fairly long setae. 

 Secretory pores were with certainty only observed at the base of Se 3 Re II <*> III in pes II — III. 



Textfigure 4. Cal. finmarchicus G. 9- (Stage II). 

 a. In lateral view X 85. b. Pes IV X 225. 



Y. (St. II). Size: Varying from 0-9 (S. W. Iceland), ri (Davis Strait), 1-3 (1 + 03) (Jan Mayen) 

 — i-6 mm. (Jan Mayen). Gran's specimens (-=- urosome) of his stage V varied from 078 — roi and 

 specimens from due d'Orleans from 1-4 — r8 mm. 



The body is more slender than in the preceding stage (textfig. 4 a). The head is sometimes 

 indistinctly separated from the first thoracic tergite, in addition to which 3 somites are found, of which 

 the last one only bears a rudimentary pair of legs. The antennulae, which reach about one segment 

 beyond the tip of the furca, consist of 18 segments only, as the segments proximal to the 11 are more 

 or less fused. The antennae and mandibulae are practically alike those of the f<j>. The number of setae of 

 the maxillulae is comparatively small; L,e has only 6 setae, Li I has only 10 spines, basipodite III 

 has 3, Ri I 1, Ri II 2, Ri III 5 and Re 7 setae. The maxillae are in the main features alike the f<j>. 

 The maxillipeds are in shape alike the preceding stages, but the Basp. Ill has in the middle only 

 2 Si, as the basal one is wanting, Ri I has a single seta, Ri II (probably Ri II o>> III) is rather elongate 



The Ingolf-Expedition. III. 4. 3 



