of Edinhurgh, Session 1883-84. 
365 
have seen of the condition of the youngest unattached individuals, 
I should judge that the larva was not very different from that of 
Ant. rosacea, 
I think it much more probable, judging from the robust nature 
of this larva, that it belongs either to one of the Arctic species, Ant. 
eschrichti, or Ant. qiiadrata, sp. n., or to Ant. liystrix^ sp. n., which 
is as yet only known from the cold area. It is very likely only a 
younger stage of the larva next to be described. 
No. 2. The stem, which is broken some 20 mm. from the calyx, 
forms an attachment to a hydroid tube at about its 30th joint, and 
is continued downwards half a dozen joints further. There are five 
discoid al joints below the rudimentary centrodorsal, which bears 
the sockets of five short cirri. Only one of them remains, how- 
ever, reaching up to the top of the basals, which make up about 
half the height of the cup. The second radials and axillaries are 
well developed, as are also the arms, which are unfortunately broken 
at about the tenth joint. But even under these circnmstances the 
head has a length of 4 mm. A slightly bifid plate, having a some- 
what worn appearance, stands up in one of the interradii of the 
disc. It may be one of the orals, or as I am more inclined to 
think, the anal plate ; for I cannot make out anything correspond- 
ing to it in the other interradii, which are, however, but imperfectly 
visible. A striking feature of this very robust larva, and one in 
which it resembles Ant. dentata rather than Ant. rosacea.^ is the 
large development of the arms before the appearance of the cirri. 
The radials and brachials are much larger than those of a recently 
detached individual of Ant. rosacea. This is also the case in a 
“ Challenger ” pentacrinoid from Ascension, which has a robust 
appearance like the one under consideration. The latter must 
certainly belong to one of the three Antedon species already men- 
tioned as occurring in the cold area, though further identification is 
impossible. 
9. Antedon liystrix, P. H. Carpenter, 1883. 
Formula,* A . 10 . ^ ‘ 
Centrodorsal hemispherical, and thickly covered with numerous 
* For an explanation of the signs used in these formulae, see F. J, Bell, 
Proc. Zool. Soc., 1882, pp, 530-535; and P. H. Carpenter, ibid., pp, 731-747. 
