208 PROFESSOR CHARLES CHILTON ON THE 



In the same year DELLA VALLE included all the forms mentioned above under 

 E. cuspidatus. 



In 1903 WALKER described a new species, E. lasvis, from the Southern Cross 

 Expedition, and said : " It may be easily distinguished from the other known species by 

 the absence of dorsal teeth on the segments and by the entire margins of the third 

 metasome segment and the first joints of the perseopoda. From E. cvspidatus, var. 

 antarctica, Thomson, it is separated by the conspicuous dactylus of the maxillipeds." 



In 1906 STEBBING combined the Challenger specimens with those described by 

 THOMSON, and gave them under the name E. antarctica, thus raising THOMSON'S variety 

 to the rank of a species. In describing it he says it is " exceedingly like E. propinquus " 

 another northern species. 



In 1907, from the National Antarctic Expedition, WALKER examined many specimens 

 of Eusirus, some of them of large size. These he referred to E. propinquus G. 0. 

 Sars, giving a few points in which they differ, but stating that these are due to age. 

 At the same time he described another new species, E. microps, " recognisable by the 

 relatively small eyes and slender hirsute legs. From its nearest ally, E. holmi 

 H. J. Hansen, it differs in the structure of the gnathopoda." He makes no further 

 comparison of these specimens with either E. antarctica or E. Isevis. 



In the same year CHEVREUX described two specimens obtained by the French 

 Antarctic Expedition as the male and female of a new species, E. laticarpus. 



It will thus be seen that the question is already pretty complicated, and that the 

 path of anyone endeavouring to identify species of Eusirus from Antarctic seas is by 

 no means free from difficulty. 



Eusirus antarcticus G. M. Thomson. 



Eusiru* cuspidatus, var. antarctica, G. M. Thomson, 1880, p. 4, and 1881, p. 26. 

 ,, longipes Stebbing, 1888, p. 965, pi. Ixxxvii. 

 antarcticns Stebbing, 1906, p. 340. 

 ,, propinquus Walker, 1907, p. 30. 

 laticarpus Chevreux, 1906B, p. 149, figs. 27-30. 

 (?) Ixois Walker, 1903A, p. 55, pi. x. figs. 70-76. 



South Orkneys, Scotia Bay, Station 325 ; 9-10 fathoms. June 1903. One 



male, not well preserved. 

 Station 201, lat. 59 43' S., long. 30 44' W. ; in clear water among floe, surface. 



13th February 1903. Temperature 30'l. One female. 

 Off Coats Land, lat. 72 31' S., long. 19 00' W. ; vertical net, 1-1000 fathoms. 



5th March 1904. Temperature 30. One female. 

 Station 4 11, Coats Land, lat. 74 l'S.,long. 22 W. ; 161 fathoms. One specimen. 



These specimens agree in nearly all respects with the description given by 

 CHKVREUX of E. laticarpus. The females agree with his, and differ from the male in 



(ROY. SOC. EDIN. TRANS., VOL. XLVIII., 490.) 



