COPEPODA 169 



That the copepodites of the stages V IV belong to the same species as the adult females is 

 especially borne out by the curious structure of the Re III pes II. That the described male, which as 

 realised from the above remarks is rather difficult to distinguish from E. norvegica, is really the hitherto 

 undescribed male, is not quite certain; but, as E. tonsa also in other respects (e. g. structure of the labrum, 

 of the young specimens) shows greater similarity to E. norvegica than to any other species, I prefer for 

 the present to refer the males and females to the same species. 



48. Euchaete glacialis H. J. Hansen. 

 (PI. VI figs 5 a d; text-figs 47 a n.) 



1886. Euchsete glacialis n sp. H. J. Hansen, p. 74, pi. XXIII 



figs 5-5 k, pi. XXIV figs i i d. 



1900 pars. norvegica Boeck. G. O. Sars, p. 58, pi. XIV. 

 1902 pars. Mrazek, p. 515. 



1903. glacialis Hansen. G. O. Sars, pp. 40 41, pi. 



XXVII. 



1904. Euchaete glacialis Hansen. Wolfenden, pp. 134 135, figs 



i, 2, 7- 



1905. Th. Scott, pp. 222 223. 



1907. Damas & Koefoed, p. 408. 



1908. v. Bremen, p. 54 fig. 60. 

 1913. Stephensen pp. 319320. 



Description. Size of specimen from Thor St 154 1904 was 10-4 mm. ; anterior division (4 4- 3-5) 

 = 7-5; urosome 3-9 mm. Sars' specimens measured 10 mm. 



The lateral corner of the thorax is somewhat triangular, and possesses in most specimens a 

 minute rounded process, which is not figured by Wolfenden and Sars (text-figs 47 a c). The genital 

 protuberance is very prominent, and has on each side of the vulva, the ventral surface of which has 

 been figured by Wolfeuden (p. 134), two distally rounded, lamelliform processes, of which the hindmost 

 is the longer. The subapical seta is distinctly shorter than the St. 2. The antennulae and mouth-limbs 

 do not differ from those of Euc/i. norvegica in any features of importance. 



The articular line between Re I and II pes I (text-figs 47 d e) is anteriorly wanting in the 

 middle, and that between Re II and III is only slightly developed, especially anteriorly. The Se i is 

 scarcely shorter than in E. norvegica (cf. Wolfenden p. 134); the Se Re II is perhaps somewhat longer 

 than the corresponding Se in E. n.; but the difference is not so marked that any character can be 

 found in this feature. 



The structure of the labrum is in the main like that of E. norvegica; the arrangement of the 

 hairs on the oral surface differs in minor details; the lateral anterior group is placed transversely, and 

 consists of about 20 rather stiff, short hairs; a sixth group, fairly well separated from the fifth, is found. 

 The lamina labialis and the serrula 6-dentata are scarcely different, but the hairs in front of the lamina 

 are distinctly different, as seen in fig. 5 a PI. VI, especially the lateral group, which consists of 3 4 

 longitudinal rows. The arrangement of the hairs on the labial lobes is somewhat different, as seen by 

 comparing figs 5 b and 3 c; especially the lateral basal group is better developed. 



f J 1 . Size of specimen from Thor St 214 was 6-21 mm.; anterior division (2-65 -f- 1-95) = 4-6; 

 urosome r6i mm. Hansen's specimens measured 77 and Sars' 8mm. 



The lateral corners (text-fig. 47 f) are, in contrast to those of E. norvegica, almost symmetrical 

 and only slightly produced, as on the right side in the species mentioned; the dorsal marginal tooth 

 is only indicated, or is very short. The first abdominal somite does not on the right side possess 

 any dorsal lateral process. 



The Ingolf-Expedition. III. 4. 22 



