COPEPODA 185 



and the Se 2 Re III does not reach the end of the segment. The pes V (fig. 54 f) resembles in most 

 respects that of E. norv. The Ri dext. is long and slender, consisting of a single segment, but divided 

 into two, about equal, divisions (of which the posterior is the more slender) by an exterior rounded emi- 

 nence, which is indicated in E. glacialis. The Re I <n> II of the right leg, which is 1*5 as long as the 

 Re III, shows by an indistinct incision indication of subdivision into a basal and a terminal segment; 

 a small Se Re I is found. The Ri sin., which is short and club-shaped, shows trace of segmentation 

 only towards the tip, and has terminally a very minute spine. The tip of the left exopodite is, as seen 

 by comparing the figures (PI. VI figs n d— e), like that of E. norv., but differs distinctly by the short 

 and clumsy form of the serrated interior lobe with two distal rows of larger and smaller teeth con- 

 verging towards the end, and by the comparatively long hairy appendage (text-fig. 54 f). 



Yq (St. V). Size: °. 4-11 mm.; anterior division (2*09 -f- roi) = 3*1; urosome roi mm. 



In two female specimens the first abdominal somite is distinctly produced below, in a single 

 male scarcely so (text-figs 54 g — h). The measurements of the antennulae and the structure of pes I — II 

 are scarcely different from those of adult females. The pes V o* does not provide features of great 

 interest (text-fig. 54 j). 



Y°. (St. IV). Size: 3-36 mm.; anterior division 2*5 mm.; posterior o-86 mm. A single female, which 

 ought perhaps to be referred to this species, was examined. 



Occurrence. The S/S Thor has taken «/ 7 1904 St. 183 6i°30 U N. i7°o8 Iy. W. Yt. 1800 M. Wire 

 9 f ?, 4 f c?, 2y$ (V), i y< ? (V), i.y? (IV). 



It has previously been recorded by Sars from several stations, from the Monaco Expedition, by 

 Farran "in small numbers at three stations" off the west coast of Ireland as far north as 55 N. 

 (io°45 W.) " at depths between 700 and and 1150 fathoms", and by Scott, taken by the Siboga Exp., 

 from 5 stations (1—2 specimens) in considerable depths. 



Remarks. As the described males and females were found together, as they corresponded fairly 

 well to each other in size, and as I did not find any species to which the males are more naturally 

 referred, I have referred them to the same species, in spite of a rather curious difference found in the 

 structure of pes I. The young specimens, on account of rounded lateral corners, size and similar 

 structure of pes I — II, were referred to the same species. 



In spite of minor differences from Sars' and Scott's descriptions, scarcely any doubt can exist, 

 that the specimens examined by the different authors belong to the same species. 



56. Euchaete gracilis G. O. Sars. 

 (Text-fig. 55.) 



1894. Euchaete barbata Brady. Th. Scott, p. 58, pi. VI fig. 17. 



1905. — gracilis n. sp. G. O. Sars, p. 16. 



1908. — quadrata n. sp. Farran, p. 43, pi. Ill figs 20 — 21. 



191 1. Euchaete quadrata Farran. Wolfenden, pp. 297— 298, fig. 



39, Taf. XXXV fig. 1. 



Description. f$. Size of specimen from St. 88 was 674 mm.; anterior division (276 + i"9°) = 

 472 mm.; urosome 2 - 02 mm. Sars' specimens measured 6-6, Farran's 6-9, Wolfenden's 5-85— 6 mm. 



The shape of the body is practically like that of E. norvegica. The lateral corners are not 

 regularly rounded as stated by the authors, but somewhat squarely truncate (text-fig. 55). The genital 



The Ingolf-Expedition. III. 4. 24 



