Perrier, p. 63.
2. Asterias polyplax.
I I
A small specimen with two long, two short and stout, and four
shorter and more delicate arms.
Port Jackson, March 1881.
3. Echinaster purpureus.
Othilia purpurea, Gray, Ann. 8f Mag. A*. H. (1) vi. p. 282.
Echinaster fallax, MiiU. 4' Trosch. Sgst. Asterid. p. 23; Perrier, p. 106.
AAHile some have s is and another five arms, not markedly differing
in length, another has one very long arm, with a madreporite on
either side of its base, and four shorter arms, of which one is very
much shorter than the r e s t ; it bears, however, indications of injury
and subsequent repair.
Port Molle; Port Denison; Thursday Island, 4 -6 fms.
4. Metrodira snhulata.
Gray, Ann. 4" Mag. N. H. (1) vi. p. 282.
Flinders, Clairmont; Alert Island, 7 fms.
5. Linckia laevigata.
Perrier, p. 137.
A dried specimen still retains very well its blue coloration.
Clairmont Island.
6. Linckia nodosa.
Perrier, p. 153.
There is not, I think, any doubt th at the four specimens from the
Arafura Sea (32-36 fms.) and Prince of Wales Channel (7 fms.)
are representatives of this species, of which Prof. Perrier has given
an admirable description; the specimens, however, on which that
description is based bore no indication of any locality.
The specimens are very much finer than those measured by
M. Perrier, E being equal to 213, 118, and 104 millim., with r 23,
18, and 13. The disk with 18 miUim. radius has apparently
received some in ju ry ; hut it may he that, in this species, there
is a difference in the sexes, and th at the specimen in question is
in a different condition of generative maturity to the others ; it is
impossible, however, to settle the question, as the example has been
dried.
7. Linckia marmorata.
Ophidiaster marmoratus, Michelin, Mag. Zool. 1845, Zooph. p. 21, pi. 10.
Linckia marmorata, Perrier, p. 135.
I f I am correct in referring to this species a series of specimens
from Port Molle and Eitzroy Island, it will be easy to understand
how it is th at M. Michelin’s species was never again recognized till
the Paris Museum came into the possession of his type ; th at would
appear to be the only example th at they possess, and, as M. Perrier
points out, the “ type ” is obviously young. The specimens before
me are clearly enough all representatives of the same species ; hut
were any one of them described it is quite possible th a t from the
description alone of th a t single specimen it would be easy to regard
some others of the series as belonging to another form.
In the first place, though aU the specimens are provided with the
intermediate plate th at connects into a pentagon the terminal one of
the “ rangée de plaques qui occupe la ligne médiane dorsale de
chaque bras,” the extent to which this is evident varies a good deal,
and one would hardly think it worthy of especial note in the largest
example were not attention directed to it by the better-marked
characters of some of the smaller. Secondly, the smallest specimen
has the dorsal plates covered with coarse granulations ; of some of
these, at any rate, it would be appropriate to say (again quoting
Perrier) “ les granules voisins de leur centre sont un peu plus gros
que les a u tre s ;” on the other hand, one, two, or more granules
near the centre acquire, in the larger specimens, a much greater
predominance, and give a somewhat different appearance to the
creature ; in the largest specimen these again have disappeared, and
the whole surface of the plates is more uniformly granular. Thirdly,
the dorsal plates may lose the regularity of outline which is so well
marked (if not exaggerated ?) in Michelin’s figure, and which is
expressed by M. Perrier in the words “ sensiblement carrée,” and
become narrower at the angles at which the pores are placed ; this
is perhaps due to the greater development in the number of pores,
of which as many as seven may in some cases be found within the
limits of one area. Lastly, it is only in the smallest specimens that
we find a double row of tubercles fringing the adamhulacral spines ;
in all the larger specimens the row is single, or, in other words, one
row of tubercles ceases to grow proportionately, and becomes obscured
in the general granulation of the actinal surface.
The only considerable point of difference between these specimens
and th at figured by Michelin lies in the remarkable coloration of
his specimen ; if, however, M. Desjardin’s example from the island
of Mauritius was immediately dried, it might have retained its colour ;
while Dr. Coppinger’s specimens, which were placed in spirit, might
very possibly have had part of their colouring-matter dissolved out.
The largest example has B equal to 50 millim.
Prince of AV*ales Channel, 7 fms.
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