882 
THE VOYAGE OF H.M.S. CHALLENGER. 
“ Several species of Tanais were obtained from deep water, one of these at Station 248 
in 2900 fathoms ; this is the greatest depth at which any Isopod is known to exist ; all 
the deep-sea species of Tanais, without exception, are entirely blind, but this fact is the 
less noteworthy since several species from shallow water are also blind. 
“ The long stay of the Challenger at Ker- 
guelen naturally resulted in the collection of 
a large number of new forms of Isopoda from 
this little explored region ; several of these, 
however, have been since described from the 
collections made during the cruise of the 
German ship ‘ Gazelle.’ 1 The Isopoda appear 
to form a more important element in the fauna 
of this region than anywhere else. According 
to Dr. v. Willemoes Suhm about 20 per cent, of 
the Kerguelen Crustacea belong to this order. 2 
“ An abundant species is Tanais wille- 
moesii, Studer. This Isopod is remarkable 
for the fact that the females carry their eggs 
in two sacs attached between the fourth 
and fifth pairs of legs. Dr. v. Willemoes 
Suhm has already referred to this peculiarity ; even in the youngest females the sacs are 
present, and with the normal shape and position, so that it is impossible to state whether 
they are entirely new and anomalous structures, or whether they result from the modifica- 
tion of the ordinary ovigerous lamellae that are met with in other Isopoda. 
“ The accompanying woodcut (fig. 326) is a representation of a very curious little 
Isopod, of which only a single example was got; the figure is greatly enlarged, since the 
specimen itself does not measure more than one-tenth of an inch in length, it is remarkable 
for the great lateral elongation of the head, so that the antennae come to be placed quite 
at the side of the body instead of being close to the median line. The epimera of all the 
segments as well as the fore part of the head and the caudal shield are fringed with a 
dense series of leaf-shaped processes ; the eyes are completely aborted. This Isopod 
evidently belongs to the family of the Asellina, and I have called it NeaseJhis 
kerguelenensis. 
“ Other characteristic Kerguelen Isopoda represented by specimens in the Challenger 
collection have been already described by Studer.” 
1 Tli. Studer, Archiv /. Natunjesch., Jahrg. xlv. Bd. i. p. 19, 1879 ; Abhandl. cl. lc. Alcad. d. Wiss. Berlin, pp. 1-28, 
1883 . 
2 Pror. Boy. Hoc. Lond., vol. xxiv. p. 590, 1876. 
