CARBONIFEROUS FISH-FAUNA, 
ornament, which consists of parallel, oblique, transverse ridges, 
diverging in pairs from this line over the flattened upper and 
lower faces and inclined towards the inserted extremity; their 
narrow posterior face impressed by a median longitudinal groove 
but without denticles. Pelvic fin-spines ornamented like the 
pectorals, but rounded in transverse section at the base and 
nearly straight. Posterior dorsal and anal fins relatively small, 
with a broad, laterally-compressed anterior spine, which is 
ornamented with longitudinal tubereulated ridges; caudal fin 
slightly forked. Two pairs of hollow, broad, triangular, free 
spines, of fibrous texture, fixed near the insertion of the pectoral 
fin-spines. 
This fish agrees with Gyracanthus in the ornamentation of its 
pectoral fin-spines and the nature of its free spines; but there is 
as yet no evidence that the last-mentioned genus possessed pelvic 
fin-spines or any median fin-spine. It may also be added that 
the pectoral fin-spines of Gyracanthides hitherto discovered do 
not exhibit any worn surfaces, while the corresponding spines of 
Gyracanthus are often much abraded and destroyed at the tip. 
GYRACANTHIDES MURRAYI, sp. nov. Plates I, II, III, IV; 
Plate V, figs. 1, 2; ext-figures 1, 2. 
1890. Rhytidaspis murrayi, F. McCoy. Loc. cit. p. 28 
(name only). 
1890. Chiraropalus langtrei, F. McCoy. Loc. cit. p. 24 
(name only). 
Type.—Head and abdominal region of fish showing pectoral 
spines (partly shown in PI. I, fig. 1). 
Specific Characters.—The type species, usually attaining a 
length of about 0.5 m., sometimes perhaps much larger, with the 
pectoral fin-spines extending nearly half of this length. Width 
between the insertion of the pectoral fin-spines probably exceed- 
ing the length of the head and branchial region in front of them ; 
the same measurement slightly more than twice as great as the 
width between the insertion of the pelvic fin-spines, of which the 
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