54i8 KEV. T. E. R. STEBBING ON 0BUSTACEAK8 [May 22, 



the penultimate joint is fully two-thirds the length of the ante- 

 penultimate. On the other hand, the specimen here identified 

 with macrura has the three terminal joints of its second maxiUipeds 

 together longer than the fourth joint, and the antepenultimate 

 thrice as long as the penultimate. But as Sars considers that 

 none of his specimens were full-grown, I abstain from regarding 

 the differences mentioned as of specific value. Mr. Vallentin's 

 specimen, of wliich unfortuuately 1 cannot give the measurements, 

 was certainly longer than the 13 mm. reached by Sars's specimen. 

 Locality. (Stanley Harbour, Falkland Islauds. 



ISOPODA. 



A S E L L O T A. 



1882. Asellota, Sars, Christiania Vidensk. Forh. no. 18, p. 58. 



1885. Asellota, Sars, Den Norske Nordhavs-Exp. vol. xiv. pt. 1, 

 p. 118. 



1893. Asellota, Stebbing, Hist. Crust., Internat. Sci. Ser. 

 vol. Ixxiv. p. 376. 



1895. Asellota, Hansen, Isop., Cumac. u. Stomat., Plankton- 

 Exp., p. 4. 



1897. Asellota, Sars, Crustacea of Norway, vol. ii. pt, 5, p. 94. 



Fam. JanikiDjE. 



1897. laniridce, Sars, Crustacea of Norway, vol. ii. pt. 5, p. 98. 



The genus Janira, Leach, 1813-1814, established in the 

 Supplement to his article " Crustaceology," was not spelt with an 

 initial iota, but was trisyllabic. 



Gen. Iais Bovallius. 



1886. Iais, Bovallius, Notes on Fam. Asellidse, pp. 4 & 50, 

 Bihang K. Svenska Vet.-Akad. Handl. vol. xi. no. 15. 



1886. Jcera (part), Beddard, 'Challenger' Isopoda, Eeports, 

 vol, xvii. p. 19. 



1887. Iais (Janthe), Pfeffer, Krebse von Siid-Georgien, p. 18. 

 This genus may be distinguished from its very near neighbour 



Jcera Leach, by the narrowness of the body, the smallness of the 

 eyes, the triunguiculate fingers on all the hmbs of the peraeon, 

 and by the uropods which are not adjacent, not inserted in a notch 

 of the pleon, and in which the peduncle is not longer than the 

 rami. 



On the last only of these four characters can much dependence 

 be placed. Sars, indeed, in his definition of Jcera includes the 

 character " dactylar joint 3-unguiculate," but the reckoning of 

 spines which justifies this would allow us to say that the dactylus 

 in Iais was quadriunguiculate. It is, however, a somew hat un- 

 substantial character. Still more so are those depending on the 

 breadth of the body and the size of the eye. In the mouth-organs 

 [32] 



