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differ in comparativeh^ unimportant details, of a kind which are
probably adaptive.
(ß) There is a marked tendency to the development of a small
number of short cirri *.
(y) And ten species have lost the cirri altogether.
(?) Of the eleven species the formula of no two is exactly the
same.
1. Antedon adeonæ.
Comatula adeonæ, J. Miiller, Gattung Comatula, p. 151.
A white line, which extends along the middle of the radiais, the
rest of which is of a reddish purple, is continued for a short though
varying distance along each of the arms.
There is a curious error in connexion with this species which
does not seem to have been noticed. Lamarck described it as
“ G. radiispinnatis denis &c. de Blainville, while quoting Lamarck,
refers also to his own figures in his ‘ Atlas ’ (pi. xxvi.) ; in this
reference he is followed by J . Miiller and by the editors of the
second edition of Lamarck. The figures, however, when referred to
are seen to be those of a species with twenty arms and with cirri
nearer thirty than twenty. I t is not perhaps necessary at this
distance of time to waste time in inquiring what species it is th a t
de Blainville has there figured.
Port Curtis and Port Denison.
2. Antedon milberti.
Comatula (Alecto) milberti, J. Miiller, p. 19.
The rich supply of this species in the present collection + amply
justifies the doubts which Mr. Carpenter has expressed to me as to
the exactness of the locality (North America) ascribed by MiiUer to
this species.
Port MoUe; Port Denison; Prince of Wales Channel; Torres
Straits.
3. Antedon pinniformis.
P. H. Carpenter, Notes Leyd. Mus. iii. p. 180.
Dundas Strait, N.W. Australia.
* So far as we know at present, c rarely appears i i the formula of an Actinometra
; in words, the cirri are rarely very numerous (more than 30) or very long
(with more than 40 joints).
t The essay on Comatula, the pagination of which is here quoted from its
separate copy, was published in 1849 in the ‘ Abhandl.’ of the Academy of
Berlin for 1847, where it occupies pp. 237-265.
I It is also well represented in a collection of Mr. E. P. Eamsay’s, of the
Australian Museum, Sydney.
4. Antedon carpenteri. (P la te X. figs. A, a-c.)
Centrodorsal a flattened d isk ; about 12 marginal cirri, of almost
20 short joints, of which the lowest are almost twice as broad as
they are lo n g ; it is not till we reach the penultimate one th at we
see a distinct spine, though the dorsal surface of most of them is
produced into a minnte protuberance.
F irst radials not visible; the second do not or do only slightly
touch, united to the third by ligament. Ten arms. F irst brachials
touch, they are nearly oblong and more than twice as wdde as long ;
the second are a little wider on their outer than their inner sid e ;
the third with a syzygy ; fourth to sixth oblong, seventh wider on
inner than outer side, eighth wider on their outer than inner, and
so on alternately ; twelfth and thirteenth serrated at their distal
edge ; the fourteenth syzygial. Thence from four to seven joints
between each syzygy. 130-180 joints in the arm.
The second pinnules on the fourth brachial are very stout, with
extraordinarily wide joints, which are armed on either side by
spinous projections ; the first pinnule is a little longer than the
third.
Colour white, with purple hands or patches, not always developed
a t the syzygies. The middle line of the arm often white.
Arm about 40 millim. long, disk 6 millim. in diameter, cirri less
than 9 millim. long.
This species has some considerable resemblances to A. serripinna,
from which, however, the pinnules alone would, as Mr. Carpenter
assures me, he sufficient to distinguish it.
Port Curtis.
5. Antedon pnmila. (P la te X. figs. B, a-h.)
Centrodorsal rather wide, rounded; with about 25 cirri, in three
rows, very delicate, of about 12 joints, which, from the fourth onward,
are a good deal longer than broad, hourglass-shaped, but a little wider
at their distal than at their proximal ends ; some are also produced
into a small spinous ventral process ; no dorsal spine developed till
the penultimate, and th at is small.
First radials ju st visible, second not in contact; axillaries tr iangular
in shape, sloping backwards in the middle line. Ten arms.
F irst brachial longer without than within, the second within than
without and projecting backwards in the middle line ; the third
a syzygy wider within than without. The succeeding joints
may he 'incised, so as to leave a lozenge-shaped space between
every two ; when this disappears, the joints which have projected
strongly forwards on either side alternately become more evenly
oblong.
Syzygies 3, 8, 12, 15; then a little rarer.
Pinnules delicate, the second longer than the first, with elongated
joints which are a little wider at their distal than at their proximal
end and are produced into a minute spine.
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