COPEPODA 



187 



tively long antenmdae and comparatively short Se 2 there is reason to suggest that the value of th< e 

 characters ought not to be exaggerated. 



57. Euchaete acuta Giesbrecht 

 (PL VI figs 12 a — c; text-figs 56 a— b.) 



1892. Euchte-te acuta n. sp. Giesbrecht, p. 246, Taf. 16 and 37. 

 1898. — Giesbr. Giesbrecht & Schmeil, p. 38. 



1903. 

 1904. 

 1904. 



I9°5- 

 1905. 



J. C. Thompson, p. 18. 



J. C. Thompson & A. Scott, p. 244. 



Wolfenden, p. m. 



Cleve, p. 190. 



G. O. Sars, p. 4. 



Farran, p. 35. 



1905. Euchsete acuta Giesbr. Esterly, p. J57 fig. 23. 



1906. — — — Pearson, p. 17. 

 f/>,. — — Farran, p. 40. 



1908. — — v. Bremen, p. 51, fig. 56. 



1909. — A. Scott, p. 6.5, pLXX figs J 9. 

 1909. — Pesta, p. 23. 



1911. — — Wolfenden, p. 299. 



1912. — — — Pesta, p. 22. 



Description. f2. Size: 4-02 ram.; anterior division (174-0-97) = 2-67 mm.; urosome 1-35 mm. 

 Giesbrecht's specimen measured 4-1 mm., Farran's 4-4 mm. and Scott's 4-2 mm. 



The genital area has on each side of the vulva a lamina-shaped process, somewhat larger on 

 the right side; the outline is, as shown in fig. 12a, somewhat different from Giesbrecht's fig. 47 (Taf. 37). 

 vScott's fig. 4 of the abdomen in dorsal view differs distinctly by the presence 

 of a right lateral process (may possibly be the process on the right side of the 

 vulva, which is visible when the animal is not examined in complete dorsal 

 viewj. The subapical seta is much longer than the St. 2. 



The antennulae, mouth-limbs and natatory limbs are scarcely different 

 from Giesbrecht's description. 



The epistoma and the anterior surface of the labrum do not show any 

 features of interest. The hairs on the oral surface of the labrum show a rather 



Text-fig. 56. Ettchate acuta 

 Giesbr. Yd [StV). 



simple arrangement. The group 1 is, as usual, placed somewhat laterallv, but a ' AMonien X 18. b. Pes V 



1 fe & r ' ' l ■ ' in anterior view / 33. 



is not distinctly separated from the group 2; the groups 3—4 are small and well 



marked out; the group 5 is fairly big. The transverse row behind the median spot Xr. 3 is short and 



narrow. No lateral group was observed (cf. fig. 12 bj. The lateral group in front of the lamina labialis 



(fig. 12 c) consists of small granules, and is well separated from the median groups; these consist, as 



shown in fig, of fairly long hairs; the inner group of granules anteriorly was not observed. 



Y<j' (St. V). Size: 372 mm.; anterior division 2-68 mm. ; urosome 1-04 mm. 



The lateral corners are rounded. The subapical setae are, as in the adult females, stronger as 

 well as much longer than the St. 2. The antennulae extend scarcely to the end of the anterior division. 

 The appendages are scarcely different. The structure of the fifth foot is seen in text-figs 56 a— b. 



Occurrence. The species was not gathered by the Ingolf Exp. ; but, as it was found by the Thor 

 at the following 3 stations, I have included it here. 



*s/ 6 1905 St. 82 5i°32 h. N. n°43 **W. Yt. 1200 M. Wire 1 f 2. 



2 % 1905 St 88 48°09 L. X. 8^30 L. W. Yt. 300 M. Wire 15 f ? — 1 yd*. 



21 1$ 1905 vSt 90 47=47 L. X. 8V/j L. W. Yt 300 M. Wire if?. 



24* 



