NARRATIVE OP THE CRUISE. 
611 
the summit of the interbrachial angle, with prominent boss and very large spine. 
Abactinal area covered with squamiform plates, bearing one to three spicules (spinelets) ; 
no true paxillse ; no definite order of arrangement. Papulae confined to the area at the 
base of the rays. Actinal interradial areas with very few ventral plates ; in some cases 
apparently wanting altogether, but these may only be young forms. Armature of 
adambulacral plates consisting of a semicircular furrow series of small uniform spines, 
radiating fan-like, with one or more large, conical, outer spines. Madreporiform body 
close to the odd interradial plate. Peculiar comb-like pedicellarise frequently present. 
“ Associated with the above-mentioned genera a/t Station 46 is an interesting little Star- 
fish which appears to hold an intermediate position between Ilyaster-, recently described 
by Danielssen and Koren, and such forms as Bathybiaster and Psilaster. It also occurs 
at Station 44 in 1700 fathoms. This genus, which is named Phoxcister, resembles in 
Fig 205 . — Porcellanaster cceruleus, Wyv. Thoms. A, abactinal aspect ; B, actinal aspect. Natural size. 
miniature the outline of the northern species of Psilaster ; the sides of the rays being, 
however, comparatively deeper and more vertical. The marginal plates are covered with 
uniform squamules and are devoid of any larger spinelets whatever. The actinal 
interradial areas are covered with squamiform spinelets encased in membrane, 
simulating those on the marginal plates. A well-defined dorsocentral protuberance or 
epiproctal cone is present, but by no means so specially developed as in Ilyaster. The 
character of the adambulacral armature is intermediate between that of Ilyaster and 
Psilaster. 
“ Psilaster is a genus which includes the well-known North Atlantic form originally 
described under the name of Astropecten andromeda, Muller and Troschel. The Challenger 
has discovered several allied species, but in the Atlantic none are found at so great a depth 
as 1000 fathoms, 
