464 On the British Lophogastrldae and Euphausiitlaj. 



Genus 4. Nematoscelis, G. 0. Sars, 1883. 

 Nematoscelis megalops^ G. O. Sars. 

 1872. ThysanoesHci horealis, Norman, M.S. in Sim, " Stalk-eyed Crust. 

 N.E. Coast of Scotland" (' Scottish Naturalist'), p. 8 (separate copy). 

 1882. Nematoscelis meyalops, G. O. Sars, "Prelim. Notices of Schizo- 

 poda of ' Challenger ' Exped." (Christ. Vidensk. Forhand.), p. 27 

 (separate cop}'). 

 1885. Nematoscelis mec/alops, G. O. Sars, Tleport ' Challenger ' Schizo- 

 poda, p. Vn, pi. xxiii. figs. 5-10, and pi. xxiv. 



Nematoscelis is remarkable on account of the ver}' great 

 length of the first pair of feet, which are even longer than in 

 Thysanoessa and differ markedly in character. In mature 

 N(matoscelis 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 appresscd 

 spinules and also several falcate-shaped spines, which louk as 

 if 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 

 p])inules towards the extremity, and at the extremity are two 

 ])orrected and greally 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 ajK'X." This is not quite correct as 

 regards the specimens I have seen. I think it well for the 

 ])rescnt to refer these to N. megalops ; but if the form should 

 hereafter prove distinct my name N. horealis 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 N. microps, G. O. Sars. 



Banff, 1862 {T. Edicard) ; Aberdeen, 1868 {G. Sim)] 

 Firth of Forth, 1892 [T. Scott) -, Kedcar, Yorkshire, April 

 1892 {T. H. Nelson) : Mus. Nor. 



In the ' Challenger ' Exjiedition N. megalops was found in 

 the middle of the South Atlantic on the line between Buenos 

 Ayres and Tristan d'Aeunha at Stations .'>ol, o32, and 333. 

 It was also taken in tlir North Atlantic off Nova Scttia. 



