REPORT ON THE ASTEROIDEA. 227 
interradial area is occupied by numerous small intermediate or ventral plates, all of which 
bear groups of spinelets similar to those above mentioned ; and most of the plates in a 
large specimen have a single flattened and pointed spinelet springing from the midst. 
The mouth-plates are elongate and ovoid, prominent, with a regular and conspicuous 
armature, consisting of a single line of short, robust, papilliform spinelets, slightly flattened 
and with rounded tops, arranged along the outer margin of the surface of the plate. The 
space between the companion series of a mouth-angle is wide and elliptical in outline. On 
the free side of the plate, and at a higher level, is a secondary series of small mouth-spines, 
closely apposed to the bases of the superficial series, which fit into the interspaces, and are 
almost invisible when viewed from above. The innermost mouth-spines are considerably 
longer than the papilliform superficial armature, and form a small fan of four parallel spine- 
lets at each mouth-angle, the outside spinelet at each side being shorter than the others. 
The madreporiform body is small, and situated rather nearer the margin than midway 
between it and the centre of the disk. 
Colour in alcohol, yellowish grey, with traces of a darker grey tint remaining here and 
there on the paxillar area. 
Locational Variation.—Two examples from Simon’s Bay are of much larger size than 
any of those which I have considered to be the type-form, and they are characterised by 
the presence of a small appressed spine on the supero-marginal plates on the lateral wall of 
the ray, near the rounding of the plate, and similar to the spines on the infero-marginal 
plates. The spinelet is wanting on a few plates in the interbrachial arc, and at the 
extremity of the ray. 
In a still larger specimen from Station 164, off Sydney, the rays are much broader and 
flatter in appearance than in the examples above mentioned, and the supero-marginal 
plates extend further on the abactinal surface, forming a comparatively broad border when 
seen from above ; and the single, delicate, appressed spine borne on the supero-marginal 
plates is even more elongate and conspicuous than in the specimens from Simon’s Bay. 
It is interesting to note that the South African form is distinctly intermediate in size 
and character between the New-Zealand and the Australian forms. Although the differ- 
ences in appearance between the two latter are very striking when viewed by themselves, I 
do not feel warranted under the circumstances, and with such a small supply of material at 
command, in marking any of these distinctions by name. When more specimens are avail- 
able, such a course may be found desirable. 
Localities—Station 167. North-west of Port Hardy, New Zealand. June 24, 1874. 
Lat. 39° 32’ 0” S., long. 171° 48’ 0” E. Depth 150 fathoms. Blue mud. Surface tem- 
perature 58°°5 Fahr. 
Station 164. South-east of Sydney. June 12, 1874. Lat. 34° 8’ 0” S., long. 
152° 0’ 0” EK. Depth 950 fathoms. Green mud. Bottom temperature 36°°5 Fabr. ; 
surface temperature 69°°5 Fahr. 
