REPORT ON THE ASTEROIDEA. 45 
is one short, robust, conical spine. Excepting one or two isolated granules or miliary 
spinelets there are no other spinelets on the plates, though at first sight the pedicellarie, 
which stand on the margin of the infero-marginal plates, might almost be considered to 
belong to the adambulacral plates. 
The mouth-plates are large and rather prominent, and their armature consists of 
a marginal series of about seven to ten short spinelets, the two innermost being much 
the largest, whilst the others are subequal or decrease slightly in size as they recede from 
the mouth. On the actinal surface of the plate there is usually a lineal series of small 
conical spines running parallel to the suture, and in the interspace between these and 
the marginal series there are one or more spines, one of which is much larger than the 
others, and is the representative of the large spine on the actinal surface of the adam- 
bulacral plates. There is frequently some irrecularity in the disposition of these inner 
spines. 
The actinal interradial areas are small, and occupied only by a few irregularly placed 
intermediate plates; the spinelets they bear are most of them modified into pedicellariz- 
like bodies similar to those elsewhere found on this species. 
The anus is central and very distinct, with several larger spinelets surrounding its 
margin. 
The madreporiform body is small but convex, and is usually less (but sometimes rather 
more) than its own diameter distant from the margin. ‘The striz are coarse and deeply 
incised. 
The papular groups at the base of the rays are small and with not more than eight to 
ten papule in each. The paxillee amongst the group are small and modified in form, and 
the crown is often represented only by the central spine. 
Colour in alcohol, a bleached greyish or yellowish white. 
Young Phase.—The smallest example (from Station 46) measures R=11 mm., 
r = 2°5 mm., and is already so far characterised that it is scarcely too much to say that 
it would be referred with but little hesitation to the species, even if found isolated. There 
are twelve supero-marginal plates, and the spines borne on these and the infero-marginal 
plates, though small, are tolerably robust in comparison to the size of the specimen. 
Robust central spinelets are already present on a number of the paxille, whilst the 
encircling series, five or six in number, are mere conical thornlets radiating apart. There 
are several large and fully developed pedicellarize on the abactinal paxillar area; similar 
large valvate pedicellarize, composed of four or five spines, are also present on the actinal 
surface, chiefly in the actinal interradial areas, but also on the infero-marginal plates, 
extending along the ray as far as the fourth or fifth plate, or occasionally further. ‘There 
are two if not more small intermediate plates in the actinal interradial areas. The 
adambulacral plates have a furrow series of four or five spinelets, with or without an 
incipient thornlet at the end of the series, and on the actinal surface of the plates is a 
