CARBONIFEROUS FISH-FAUNA, 
Fig. 2.—Gyracanthides murrayt, A. 8. Woodw.; pelvic fin-spine, side-view, nat. size. 
traced from the base towards the slender apex of the spine, where 
there is an indication of a worn surface. The base of insertion is 
very extensive, as usual, its length probably equalling one-half 
the total length of the spime. One fine example apparently of 
this spine, obtained by Mr. Sweet from Bed W in the Mansfield 
section, is nearly twice as large as the original of text-fig. 2. Its 
outer ornamented face is broken away on the exposed side, but 
the tissue of the spine is sufficiently well preserved for micro- 
scopical examination. It exhibits a remarkably coarse vascular 
structure, identical with that described by Agassiz in Gyra- 
canthus.* 
Median Fins.—The specimen represented in Pl. V, fig. 1, is 
‘very imperfect anteriorly, showing only a hollow mould of parts 
of the pectoral fin-spines, one displaced large free pectoral spine, 
and part of one of the pelvic fin-spines; but it is important as 
displaying the caudal region of the fish, with traces of the median 
fins. This fossil seems to have been selected by McCoy (Joc. cit., 
p. 24) as the type of a species which he intended to describe 
under the name of Chiraropalus langtrei; but the paired spines 
already mentioned prove that it really belongs to the Gyracan- 
thides now under consideration. As shown by the figure, there 
is part of a fin-spine above the dorsal border of the trunk (at ¢) 
opposite the insertion of the pelvic fin-spine. In another more 
fragmentary specimen (PI. V, fig. 2) there is also a small spine, 
chiefly shown by the mould of its internal cavity (2) nearly 
opposite a piece of spine (a) which seems to represent the pelvic 
fin-spine. The first example might possibly be the tip of one of 
1 L. Agassiz, “Rech, Poiss. Foss.,” vol. iii. (1843), p. 214, pl. A, fig. 6. 
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