CARBONIFEROUS FISH-FAUNA, 
feeble radiating crimping round the base. This is best shown in 
the original of Pl. II, fig. 2 (enlarged in fig. 2¢), but is also 
observable in impression in other specimens from which the 
diagrams, Pl. I, fig. 7b and Pl. II, fig. 1f, have been made. 
Less accurate drawings are given in Pl. V, figs. 14, 2a. The 
imperfect fossil represented in Pl. VI. also seems to be an 
impression of a fragment of this dermal armour, but the drawing 
exaggerates the crimping of the tubercles and gives a false 
appearance of lines bounding polygonal tesserze. ‘This specimen 
may possibly have been interpreted by MeCoy as part of the 
shield of his supposed Cephalaspidian, Rhytidaspis murrayi. 
Observations.—This_ species is named in honour of Mr. 
Reginald Murray, who discovered the first evidence of it at 
Mansfield many years ago. Most of the remains of Gyracan- 
thides in the collection evidently belong to it, though some 
fragments may perhaps represent other species which cannot yet 
be distinguished. 
Family ACANTHODID &#. 
Genus ACANTHODES, Agassiz. 
Rech. Poiss. Foss., vol. ii., pt. 1., 1833, p. 19. 
¢ I I 
A typical slender species of this genus is represented in the 
Mansfield collection by an imperfect trunk and other fragments. 
It evidently belongs to the group which is characteristic of the 
Carboniferous and Permian formations in the northern 
hemisphere. 
ACANTHODES AUSTRALIS, sp. nov. Plate V, fig. 3; Plate VII, 
figs. 
Type.—Caudal region of fish (Pl. VII, fig. 1). 
Specific Characters.—A very slender species probably attain- 
ing a length of not less than 0.8m. Anal fin-spine much larger 
than the dorsal fin-spine, which is more curved and inserted 
further back than the former. Depth of hinder end of caudal 
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