'Alert' 1881-2

170 COLLECTIONS FROM MELANESIA.
The first four or five bracliials have the sides pretty even, the
succeeding are very distinctly wedge-shaped, and the. distal edge
becomes faintly denticulated. Further out the wedge becomes wider,
and the denticulation disappears.
Syzygies 3, 10, 14 ; then about three joints between each. The
pinnules
longest.
generally are delicate and short, the first rather the
Arms not very long, thin ; cirri about 10 mm. long; disk as much
as 30 mm. in diameter, Ovving to the extensive development of the
interradial plating which extends to the distichal axillaries.
Colour yellowish green with darker spots, patches, or lines ; the
ends of the arms and the lower surface darker, or the upper surface
may be of a pale flesh-colour.
Thursday Island.
28. Actinometra, sp. juv.
It is very possible that a young specimen from Dundas Strait belongs
to a species, A. piirjmrea, of which a single example is alone
known ; and that, as llr. Carpenter informs me, is in rather bad
condition. It is to be hoped that further exploration will result
in the discovery of more representatives of this incompletely known
form.
General Remarks on Distribtttion.
After concluding the survey of the Echinoderms collected in the
Australian seas by Dr. Coppinger, I arrived at certain results, which
it is unnecessary now to state ; for mj views have since been profoundly
modified by what I have since learnt from a closer study of
the marine fauna of Port Jackson than was possible with the comparatively
scanty material that was in mjr hands two years ago, when
the body of this Report was being framed.
I have learnt since, thanks to the opportunities afforded me by
arrangements made with Mr. E. P. Eamsay, the Curator of the
Australian Museum, Sydney, what are the characters of the Port-
Jackson fauna, and what is the extent of its resemblance to that
of Port Molle and Torres Straits.
I have, in the first place, learnt that no view can be more erroneous
than one which speaks of an Australian (marine) fauna without
some sort of qualification ; Cape York and Port MoDe are as much
part of Australia as Port Jackson, but between the two faunae the
resemblance is as slight as is in the nature of things possible.
This statement is abundantly proved by the first two tables of
distribution which I now give, and which are based on the 27 Echinids
and 16 Ophiurids from the collection of the Sydney Museum.