PLUTONASTER. 63 
a-c, Faeroe Channel, 530 fms. ‘Knight Errant ’ Exp. (St. 7). 
d-f. Faeroe Channel, 555 fms. ‘ Triton’ Exp. (St. 11). 
g-j. Faeroe Channel (Thomson coll.). John Murray, Esq. 
k. West of Donegal Bay, 1360 fms. ‘Porcupine’ Exp. (St. 19). 
2. Plutonaster pareli. 
Astropecten parelii, Diib. § Kor. VetAkad. Hdly. 1844 (1846), 
p- 247, pl. vii. figs. 14-16. 
Archaster parelii, Sars, Norg. Ech. (1861) p. 35; Thomson, Depths 
of the Sea, (1873) pp. 122, 181, 456. 
eee (Tethyaster) pareli, Sladen, Chall. Rep. Ast. (1889) 
p- 102. 
R = 2r (nearly). 
Arms short and broad, disk large; marginals very large, extend- 
ing considerably on to both ventral and dorsal surfaces. Ambulacra 
rather narrow, bordered by a very large number of spines; these 
are in five transverse rows, and the inner have again five in each 
long row ; in the outer the spines are much larger and less numer- 
ous. ‘The intermediate plates, which extend buta short way beyond 
the disk, are covered with large flat granules and a few larger flat- 
tened spines, of much the same size as the largest of the adambu- 
lacral spines. The inferomarginals and superomarginals at the 
rounded angles of the disk very long, wider within than without ; 
further out the plates are wider, and the outer and inner edges are 
of the same breadth. About twenty-five to thirty plates on either 
side of each arm; these plates are sometimes broken into two; they 
are in each row covered by a close pavement of polygonal plates, 
some of which, in the lower series, become prolonged into distinct 
spines. The dorsal surface is occupied by a regular pavement of 
quadrate or polygonal plates, each of which may be resolved into a 
number of fine spines flattened at their free ends. Among them 
the madreporite, which is situated not far from the centre, may be 
easily detected. 
Colour said by Diiben and Koren to be “ intense sanguineus ;” in 
spirit creamy yellow, the marginals lighter than the rest. 
R. ip 
19 8 
Distribution. Eastern side of North Atlantic north of Great 
Britain. Very rare in the British seas. 155-1608 fms. 
a, North of Ireland, 1860 fms. ‘ Poreupine’ Exp. 
