464 On the British Lophogastride and Euphausiide. 
Genus 4. NEMATOSCELIS, G. O. Sars, 1883. 
Nematoscelis megalops, G. O. Sars. 
1872. Thysanoessa borealis, Norman, MS, in Sim, “ Stalk-eyed Crust. 
N.E. Coast of Scotland” (‘Scottish Naturalist’), p. 8 (separate copy). 
1882. Nematoscelis megalops, G. O. Sars, “ Prelim. Notices of Schizo- 
poda of ‘Challenger’ Exped.” (Christ. Vidensk. Forhand.), p. 27 
(separate copy). 
1885. Nematoscelis megalops, G. O. Sars, Report ‘Challenger’ Schizo- 
poda, p. 127, pl. xxiii. figs. 5-10, and pl. xxiv. 
Nematoscelis is remarkable on account of the very great 
length of the first pair of feet, which are even longer than in 
Thysanoessa and differ markedly in character. In mature 
Nematoscelis megalops these legs exceed the length of the 
body, the meral and two following joints are very long and 
slender, especially the meros, and at the extremity of the 
meros the limb is capable of being bent back upon itself. 
The meros has a row on each side of small nearly appressed 
spinules and also several faleate-shaped spines, which look as 
it they might serve the purpose of grasping the propodos 
when bent back upon the meros. ‘The carpus is quite smooth, 
the propodos is almost naked, but there are two or three small 
spinules towards the extremity, and at the extremity are two 
porrected and greatly developed spines, which, with six other 
similar spines springing from the last joint (dactylus ?), 
form a remarkable terminal brush to the limb. These eight 
terminal spines are serrated in a very peculiar spiral manner, 
and the serrations point backwards. The ventral preanal 
spine in the Scotch examples is either bifid, as figured by 
Sars, or simple. 
The British examples appear in all respects to agree with 
Sars’s description and figures of N. megalops, except that he 
writes of the first legs that the meros and subsequent joints 
lack “every trace of marginal bristles, being quite naked 
throughout, save at the apex.” This is not quite correct as 
regards the specimens I have seen. I think it well for the 
present to refer these to N. megalops; but if the form should 
hereafter prove distinct my name N. borealis can be adopted. 
Specimens not full-grown have the first legs shorter than 
the body, the eyes smaller and with faint traces of bilobation, 
the antennal scale proportionately shorter, and thus come 
rather suspiciously near to V. microps, G. O. Sars. 
Banff, 1862 (T. Edward); Aberdeen, 1868 (G. Sim) ; 
Firth of Forth, 1892 (7. Scott) ; Redcar, Yorkshire, April 
1892 (7. H. Nelson): Mus. Nor. 
In the ‘ Challenger’ Expedition N. megalops was found in 
the middle of the South Atlantic on the line between Buenos 
Ayres and Tristan d’Acunha at Stations 331, 332, and 333. 
It was also taken in the North Atlantic off Nova Scctia. 
