IIO CRUSTACEA MALACOSTRACA. 



outer edge to the tip of the marginal spine is but little less than twice as long as the oblique 

 setigerous distal edge measured to the base of the marginal spine, whereas in P. roseum the smooth 

 outer edo-e is only 3/ 2 times longer than the setigerous distal edge. The telsou almost as in P. roseum. 



Occurrence. The "In golf has once taken the species. 



North-West of the Faeroes: St. 138: 63° 26' N. L., 7° 56' W. L., 471 fm., temp. -=-o-6°; 8 specimens. 

 The Ryder expedition has also taken a single specimen, a male, south of Jan Mayeu : 70 32' N. L., 

 8° 10' W. L., 470 fm. Ohliu gives P. roseum from 3 localities at East Greenland, namely, in Franz 

 Joseph Fjord, off the same fjord, and at 74 30' N. L., i8°4o'W. L., depths from 42—53 fm. and clown 

 to 132 fm.; as the localities are distinctly arctic and his specimens, as mentioned above, agree with 

 P. frigiduiii in size, it is undoubtedly this species and not P. roseum which he has had in his hands. 



Distribution. G. O. Sars in the Norwegian North-Atlantic Expedition mentions his having 

 had unusually large specimens of P. roseum from two localities in the cold area: the one of these at 

 63°io'N. L. off Norway, depth 417 fm., temp, -f ro°, the other is given as from "the tract of Ocean 

 south-west of Jan Mayen (Stat. 251)" — but some error must have crept in here as Stat. 251 lies off 

 Lofoten (depth 634 fm., temp. -=- 1-3°). The specimens from these two localities have certainly been 

 P. frigidum. Further, I am inclined to believe that Stuxberg's determination, Matotschkiu Shar, 

 60—70 fm., should also be relegated to this species. 



24. Pseudomma affine G. O. Sars. 



1870. Pseudomma affine G. O. Sars, Forh. Vid. Selsk., Christiania, Aar 1869, p. 156. 

 ! 1872. — G. O. Sars, Mon. Norges Mysider, II, p. 57, Tab. V, Fig. 13 — 22. 



! 1906. — Holt & Tattersall, Fisheries, Ireland, Sci. Invest, 1904, V, p. 27, PI. Ill, figs. 1—6. 



Occurrence. The species has only been taken by the "Thor", at the following locality. 



South-West of the Faeroes: 6i° 08' N. L., 9 28' W. L., 434 fm.; many specimens. 



Distribution. It has been taken in the north of western Norway up to Lofoten, 100—200 fm. 

 (G. O. Sars). Has further been trawled by the "Thor" in the North Sea at 58 32' N. L., 4 18' E. L., 

 148 fm., and several times west of Ireland in depths from 120 to 500 fm. (Holt & Tattersall). Lo Bianco 

 states that he has seen specimens taken at 3 places in depths of over 500 and 600 fm. in the Mediter- 

 ranean, but I greatly doubt the correctness of his determination. 



Remarks. As shown by Sars, the eye-plate in the females is produced forwards in a cleft 

 process, by means of which they are easily known from P. roseum, but on the other hand the extent 

 of the marginal serrulation does not agree with Sars' description, as in my specimens the posterior 

 part of the lateral margin is smooth, so that the serrulated part is not much longer than in P. roseum, 

 whereas according to Sars the serrulation in P. affine reaches to behind the lateral corner. The telson 

 in my specimens shows an intermediate stage between Sars' figures of P. roseum and P. affine, its 

 posterior margin being less broad than in the latter and with 3, at most 4, pairs of spines. Never- 

 theless I consider that my specimens, especially on account of the form of the eye-plate at the centre 

 of its anterior margin, must be referred to P. affine G. O. S. 



