566 CARBONIFEROUS LABYRINTHODONT 
the Airdrie workings. I had every reason to believe some of these 
vertebre to belong to Anthracosaurus, and it was with that conviction 
in my mind that I ventured to caution the members of the Geological 
Society, on the occasion of the reading of Mr. Marsh’s paper on 
“ Fosaurus Acadianus,’* against too hastily concluding that the 
vertebral centra, which he had found in the Nova-Scotian coalfield 
and then described, were necessarily Ichthyosaurian,—seeing that I 
had much reason to suspect that they might belong either to 
Labyrinthodonts or to some genus of intermediate characters, 
between Labyrinthodonts and Ichthyosaurians. 
Within the last few days Mr. Russell has sent me the vertebra of 
which an outline view is given in fig. 2 (one-half the natural size). It 
Fig. 2.—A. Dorsal vertebra of Anthracosaurus, zewed from behind. B. Rib of the 
same Amphibian. 
A.—a. Body of the vertebra. 6. The longer division of the transverse process, and 
ce. The shorter division, @. Anterior zygapophysis. e. Posterior zygapophysis.  Spinous 
process. g. Neural canal. B.—a. Capitulum. 6. Tuberculum. 
was found in the same bed as that which yielded the skull of 
alnthracosaurus, and corresponds very well in size with what one 
might expect would be the dimensions of a dorsal vertebra of that 
animal. Associated with it on the same slab are several other less 
complete vertebree and the remains of two ribs. 
The body of the vertebra is greatly flattened from before back- 
wards, as the subjoined measurements will show. The exposed 
articular surface is concave, and a section which I have had made of 
* See Quart. Journ. Geol. Soc., vol. xix, 1863, p. 52. 
