REPORT ON THE ASTEROIDEA. 455 
superior series are scarcely distinguishable from the paxille of the abactinal surface 
generally. 
The adambulacral plates are large, and their armature consists of two series of spines. 
(1.) A furrow series of four or five short, flat, lanceolate spinelets, each in a membranous 
sac, which radiate apart and form a fan on the furrow margin of the plate. (2.) An 
actinal series of four or five large robust spines arranged in a straight line on the actinal 
surface of the plate at right angles to the furrow. These’ spinelets are thickly covered 
with membrane, and normally decrease in size as they recede from tbe furrow. The 
general surface of the plate is covered with membrane. 
The mouth-plates are moderately large. Their armature consists of a marginal series 
of about nine spinelets on each plate, the innermost three on each plate being much 
larger than the succeeding ones, and enveloped in wide membranous sacs, which give them 
a compressed lanceolate appearance ; the outer spinelets are much smaller, subconical or 
cylindrical in appearance, and diminish in size as they recede from the mouth. On the 
actinal surface of each plate is a lineal series, parallel to the median suture, of five robust 
sacculated spines which diminish in size as they recede from the mouth, the innermost 
being larger than any of the other mouth-spines. 
In the actinal interradial areas of the disk there are three or four series of small actinal 
intermediate plates, which bear small, compact, well-defined paxilliform groups of four 
to six short equal spinelets; only the innermost of these series extends more than a little 
way beyond the base of the ray. 
The madreporiform body is small, and is situated rather nearer the centre of the disk 
than midway between that point and the margin. Its surface is slightly convex, and 
the striations are fine. 
The ambulacral tube-feet have large, fleshy, centrally-invaginated, terminal disks. 
Colour in alcohol, a bleached greyish white. 
Locality.—Station 308. South of Wellington Island, west coast of Patagonia. 
January 5, 1876. Lat. 50° 8’ 30” S., long. 74° 41/0” W. Depth 175 fathoms. Blue 
mud. Surface temperature 51°:7 Fahr. 
Remarks.—Solaster regularis is characterised by the length of the rays, and by the 
comparatively large and widely-spaced paxille of the abactinal surface : characters which, 
taken in conjunction with the number of the rays and other minor points of detail, at once 
distinguish the species from its allies. 
4. Solaster subarcuatus, n. sp. (Pl. LXX. fig. 2; Pl. LXXII. figs. 7 and 8). 
Rays nin R=38 mm.; r=12 mm. R>3r. Breadth of a ray at the base, about 
7 mm. or rather less. 
The rays are moderately elongate, and taper only slightly on the inner half of their 
length, but more rapidly on their outer half, remaining, however, rather broad even to 
