72 



COPEPODA 



14. Spinocalanus magnus Wolf. 



1904. Spinocalanus magnus 11. sp. Wolfenden, p. 118. 



1905. — Wolf. Farran, pp. 30 — 31, pi. IV 



figs. 1 — 12. 



1906. — Pearson, pp. 10 — 11. 



1907. — Damas & Koefoed, p. 409. 



1908. Spinocalanus magnus Wolf. Farran. p. 27. 

 1908. — v. Bremen, p. 29, fig. 29. 



191 1? Wolfenden, pp. 216—217, 



text-f. 8, pi. XXV figs. 3—5. 



Description, f $. Size of female from Thor St. 82 2 - 8 mm.; anterior division measured 2*2; uro- 

 some o-6 mm. Wolfenden's specimens measured 275 and Farran's 2*9 mm. 



As far as conld be made out by the examination of the two very mutilated specimens, they 

 do not seem to differ in any feature of interest from Farran's description. 



In the second pair of legs no glandular pores were observed in the first outer segment, but a 

 distinct one in the second segment, and three near the base of Se in the third outer segment. 



In front of the labrum proper, which is very prominent, a smoothly rounded elevation was 

 found; the structure of the labrum etc. was not examined in detail. 



Occurrence. Of this species I have only examined two mutilated females, gathered by the 

 Thor M/ 6 1905 St. 82 5i°oo h. N. 11 "43 h. W. Yt. 1200 M. Wire. 



Distribution. This species is according to Farran of frequent occurrence on the west coast 

 of Ireland "from the surface to rooo fathoms, though never very plentiful". According to Koefoed 

 & Damas it is found "dans la mer du Gronlaud: de 800 a au moius r8oo metres". According to the 

 tables prepared by Koefoed, it has been found at four stations, but according to the records from 

 each single station it has only been found at St. 22 79 L,. N. i°52 L,. E. 800 — 1350 metres and at St. 48 

 71 L. N. i8°58 L,. W. 800 — 1000 metres. The species is by Wolfenden recorded from the Antarctic, 

 but he is probably not right in referring the Antarctic animals to the northern species, as his figure 

 shows the genital somite less distinctly produced. 



Aetideidae G. O. Sars. 



Ljttle by little a good many genera of the Aetideidae have been established; these genera are not 

 at all of equal value, and in their definition not the same principles have been followed. My material 

 has not been sufficiently exhaustive for a final solution of the question, but nevertheless a few remarks 

 upon the value and the position of the genera, which I have examined, may be useful. 



As a whole I think that undue stress has been placed on the presence or absence of the 

 lamelli-formed setae or spines along the inner margin of second basipodite in the fourth pair of legs. 

 Chiridius and Aetidiopsis are the only genera in which marginal setae of usual structure without 

 spines are found; in Aetidius (PL II fig. ic) terminally and posteriorly a few teeth were found in 

 addition to the iisual .slender setae. In most species of Gatdius, Gactamis and Enchirella the setae are 

 transformed into more or less well developed spines. In Underclicrte minor and nearly related species 

 the margin is either completely smooth or possessses a few terminal teeth (cf. text-figure) and in Chiru- 

 dina, the margin is either completely smooth as in Ch. Streets!, or possesses well developed spines 



