30 FOSSIL ASTEROIDEA. 
Remarks.—It will be at once seen on referring to the figures that Woodward’s 
Pentagonaster lwnatus, which is drawn on Pl. IV, fig. 1 a, of this Monograph, is a 
distinct species. The rays are more produced, and are narrower at the base. The 
infero-marginal plates are twice as numerous, the marginal border is less broad, 
and the plates are much shorter in proportion to their breadth. Their punctation 
is also different. The actinal intermediate plates are smaller in relation to the size 
of the actinal interradial areas, and their punctation is different from that which 
characterises Pentagonaster megaloplaz. ‘The armature of the adambulacral plates 
also appears to be more regular in its arrangement. 
Under these circumstances I have no hesitation in considering the form under 
description a distinct species. I much regret having to impose a new name, as 
this form has for a long time been known under the specific name of lunatus ; 
the course, however, seems unavoidable, as the actual type of the real Pentago- 
naster lunatus described by Woodward is in existence, and there can, in my 
opinion, be no question as to its being a different species. 
Since the preceding sheet was printed off I have found several specimens in 
the British Museum which show the abactinal aspect of the disk. I have little 
hesitation in referring these examples to Pentagonaster megaloplax, and a drawing 
of one of them is given on Pl. XIII, fig. la. The infero-marginal plates all show 
more or less distinctly the characteristic ‘‘ scrobiculate ” or areolated pits already 
described. A similar ornamentation also extends upon the supero-marginal 
plates, but is confined to the lateral wall which falls in the margin of the disk. 
The curvature which unites the abactinal and lateral areas of the plate is more or 
less abrupt, and the lateral wall of the disk is consequently vertical and not 
rounded, as arule. The abactinal area of the supero-marginal plates is covered 
with small, uniform, granular eminences (see Pl. XIII, fig. 1b). Two or three 
supero-marginal plates at the extremity of the ray meet the corresponding plates 
of the opposite side of the ray in the median radial line, and a rapid diminution 
in breadth occurs as they approach the extremity. 
Genus—METOPASTER, Sladen. 
[Mérwrov = a cheek-piece. | 
Body depressed and pentagonal or stellato-pentagonal in contour, the rays 
being produced to a very slight degree. Marginal plates covered with well- 
spaced uniform punctations, upon which granules were originally borne, and 
surrounded by a narrow depressed border with very minute and crowded puncta- 
