ISOPODA. 15 



ramus is only half as broad and half as long as the inner, with similar armature on 

 the distal half. 



Length 6 inillims., breadth 1*5 millims. 



Locality : Station V., north end of Chilaw Paar, February 2, 1902, 9 to 11 

 fathoms. 



The specific name is chosen out of respect to the president of the Linnean Society, 

 to whose ever watchful activity in the interests of science the collection of species 

 here described is due. 



Hansenolana, Stebbing. 



1900, Hansenolana, Stubbing, in Wii.t.ey's 'Zoological Results,' pt. 5, p. 634. 



The species H. anisopous, for which this genus was originally established, shows, as 

 I observed at the time, various points of resemblance to Oirolana sphceromiformis, 

 Hansen. While retaining the latter in the genus Oirolana, Hansen himself forcibly 

 calls attention to the singularity of its appearance. He had at command only one 

 specimen, a female, not ovigerous, 4 "25 millims. long, from St. Thomas, in the West 

 Indies. The examination of a male specimen in Professor Herdman's collection 

 induces me now to transfer the species to Hansenolana, the definition of which will 

 in consecpience require to be modified as follows : 



Head transverse, produced into a process between the two pairs of antennas ; first 

 five segments of pleon very short. Eyes small and wide apart. Mouth organs nearly 

 as in Oirolana, but on the inner plate of the first maxillre the three seta? are spine- 

 like and not coarsely plumose. In the second maxilke the outer pan of plates carry 

 very few spines. First gnathopods with the sixth joint broad. First pleopods with 

 narrow rami. Male appendix of the second pleopods attached at some distance from 

 the base of the ramus. 



The two species which at present fall under this definition are easily distin- 

 guished : 



Apex of telsonic segment broad. 1. II. anisopous, Stebbing. 

 Apex of telsonic segment narrow. 2. H. sphceromiformis (Hansen). 



Between these two may, perhaps, be placed Oirolana hanseni, Bonnier (' Ann. 

 Univ. Lyon,' vol. 26, p. 574, 1896), originally described from an obviously juvenile 

 specimen, and now (1905) re-described by Hansen from specimens probably still 

 immature. In this species the telsonic segment has an apex much less broad than 

 that of H. anisopous, but considerably broader than that of H. spluevomiformis. 



Hansenolana sphseroniiformis (Hansen) Plate II. (B). 



1890, Cirolana sphaeromiformis, H. J. Hansen, ' Vid. Selsk. Skr.,' ser. 6, vol. 5, pp. 319, 351, pi. 4, fig. 3-3</. 



1900, Cirolana sphaeromiforinis, Stebbing, in Wu, ley's 'Zoological Results,' pt. 5, p. G34. 



1901, Cirolana sphaeromiformis, H. Richardson, 'Proc. U.S. Mus.,' vol. 23, p. 512. 



Hansen's full description, together with Ids figures of the female, and those here 



