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being only 14 millim. in length. The number of radiating ridges
in the terminal valves varies considerably : the type has ten in
tho front one, and nine in the posterior ; the single specimen from
Port Molle has the same number in front, but one less behind; a
tldrd example has seventeen anterior and sixteen posterior ones.
The central valves are arched, but exhibit a carina a t the vertex.
The two radiating costæ arc sometimes more or less double at the
outer etrxemities. The longitudinal thread-like liræ are rather
granular through being connected with the still finer cross raised
linos ; they are fairly regular upon tho greater part of the surface,
but down tho centre form an irregidar network, not unlike the
reticulation of a thimble. Tho interior of the valves is for the most
])art pale greenish white, hut towards the straight posterior margin
of the central ones a buff tin t prevails. The lamina of insertion in
tho front valve is divided (a single specimen only has been examined)
by eight minute notches into nine subequal squarelj’-cut curved
teeth, together forming a festooned semicircle ; from each slit a
feeble groove runs to the vertex corresponding to an external rib.
The central valves have a single notch on each side immediately
beneath the termination of tho anterior of tho two external ridges.
The lamina is turned outward at this point and also at the other
rib, forming a little festoon. The last plate has nine notches, one
corresponding to each rib, with a single (probably unusual) exception,
Avhere there are two. The vertex in this vahæ is central. The
scales of the girdle are excessively minute, densely crowded, hardly
visible under an ordinary lens, and in alternate light and dark patches.
1 1 1 . Chiton (Callistochiton) coppingeri. (P late VI. fig. E.)
Shell elongate, greenish white, stained with a dark green colour
along each side near the girdle, with a paler indistinct stripe on
each side of the central line, the apex of the valves being somewhat
livid. Central valves with a straight posterior margin, arched, with
only the faintest indication of a carina at the vertex. Lateral areas
somewhat raised, with two radiating rows of coarse transverse rngæ,
of which the hinder or marginal aro the largest. The surface
between them is finely granular. Central areas convered with a
more or less criss-cross granulation, the grannies at the centre being
A'ery minnte, and gradually increasing in size towards the sides,
Avhere there is very little of the criss-cross arrangement seen at the
vertex, hut rather a longitudinal disposition of them. The front
valve is minutely granulated and has about twenty fine radiating
ridges, here and there some of them bifurcating near the circumference.
Posterior valve rather large, concave behind the subcentral
mucro, in front of which the surface is sculptured in the same
manner as the front of the central valve, as is usual Avith most, if
not all, Chitons. The posterior half is finely grained and sparsely
covered with pustules of different shapes and sizes, the coarsest
being near the margin and the smallest near the centre. The in-
sertional plates are thin, with twelve slits iu the last, at unequal
distances, eleven in the front one, and one on each side of the intermediate
valves. The interior is pale bluish, the latter valves haA’ing
an olive-brown stain radiating from the A’ertex behind on each side,
and the twm terminal valves have marks of the same colour near the
middle.
The girdle is covered with alternately pinkish and dark greyish
patches of fine oval compressed imbricating scales, of which those
towards the outer margin are much smaller than those near the
valves.
Length without girdle 21 millim. ; diameter of fifth central plate 8.
Bab. Port Jackson (Coppinger).
This species is closely allied to C. antiquus, but is differently aud
more finely sculptured and the scales on the mantle are larger.
^ 112. Chiton (A.canthopleura) spiniger.
Cliitoii spiniger, Soiverby, Conch. III. fig. 68; Beeve, Conch. Icon.
fig. 75; Gray, 1857,Gì« * Moll. Brit. Mus. p. 184 (Maiigeiia),; Dali,
Bull. U.S. Nat. Mus. i. p. 80 ( Acantliopleura).
Chiton granatas, tocew, Co/icA./cow. fig. 24. ^ _
Chiton macgillivrayi, A. Adams, Proc. Zool. Sue. Iboo, p. 120.
Acantliopleura giareosa, in Mus. Cuminy.
Mangeria oweifii, Gray, Guide Moll. p. 184. _ , r-
? Chiton boi'bonicus, Deshayes, Moll, de Béunion, p. 3 /, pi. v. fig.s.
? Chiton piceus, Beeve {non Gmelin), Coneh. Icon.Jò^. /O.
= Chiton obe,sus, Shuttleworth, Bern. Mittheil. 1853, p. 79.
? Chiton cumnnghamii, Beeve, I. c. fig. 18.
Hah. Philippine Islands (Cuming); Port Essington (Juices);
Port Molle and Clairmont aud Bird Islands (Coppinger); Eiji, for
C. macgillivrayi. _ _ , , t t
The specific difference, if it exist, between the \\ est-indian
C. pkexis of Gmelin and C. spiniger is not very apparent. On close
comparison I find th at the central valves of the former are as a rule
more peaked posteriorly, the colour within is hluish, with a conspicuous
mark, almost black, at the jugal sinus. On separating
these valves the greatest diameter is found to exist at the posterior
margin, the lamina? of insertion narrowing in front. On the contrary,
in G. spiiniger the greatest width is across the lamina; anterior
to the lateral notch. There appears to be very little difference in
the insertion-teeth of the first and last valves of these two forms.
113. Chiton (Acanthoplenra) incanus.
Chiton iiicaiins, Gould, Proc. Bust. Soc. Bat. Hist. Ì8-Ì6, \xil. ii.
p. 145; ‘Otia,' pp. 6, 248 (Mangeria); Wilkes s Lxplor. E.vped.
p. 315, figs. 432, 432 a.
Hab. New 8outh AYales (Gould); ^ Port Jackson (Coppinger);
Stewart Island, New Zealand (C. Tradì, E.sq., in Brit. AIus.).
Externally this species bears considerable resemblance to C. spiniger,
both as regards the sculpture of the valves and the character
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