414 
■ ELEMENTS OF GEOLOGY. 
same stony mass. Dr. Wyman of Boston pronounced the 
reptile to be allied in structure to Menohranchus and Me- 
nopoma^ species of batrachians, now inhabiting the North 
American rivers. The same view was afterwards confirmed 
by Professor Owen, who also pointed out the resemblance of 
the cranial plates to those seen in the skull of Archegosmirus 
and LdbyrinthodonA" Whether the creature had crept into 
the hollow tree while its top was still open to the air, or 
whether it was washed in with mud during a flood, or in 
whatever other manner it entered, must be matter of con¬ 
jecture. 
Foot-prints of two reptiles of difierent sizes had previous¬ 
ly been observed by Dr. Harding and Dr. Gesner on ripple- 
marked flags of the lower coal-measures in Nova Scotia (No. 
2, Fig. 447, p. 418), evidently made by quadrupeds walking 
on the ancient beach, or out of the water, just as the recent 
Menopoma is sometimes observed to do. 
The remains of a second and smaller species of Dendrer- 
peton, Oioeni^ were also found accompanying the larger 
one, and still retaining some of its dermal appendages; and 
in the same tree were the bones of a third small lizard-like 
reptile, Hylonomus Lyelli^ seven inches long, with stout hind 
limbs, and fore limbs comparatively slender, supposed by Dr. 
Dawson to be capable of walking and running on land.f 
In a second specimen of an erect stump of a hollow tree 
15 inches in diameter, the ribbed bark of which showed that 
it was a Sigillaria, and which belonged to the same forest as 
the specimen examined by us in 1852, Dr. Dawson obtained 
not only fifty specimens of Pupa vetusta (Fig. 442), and nine 
skeletons of reptiles belonging to four species, but also sev¬ 
eral examples of an articulated animal resembling the recent 
Fig. 441. 
6 
Xylobius Sigillarice, Dawson. Coal, Nova Scotia. 
a. Natural size. b. Anterior part, magnified, c. Caudal extremity, magnified. 
centipede or gally-worm, a creature which feeds on decayed 
vegetable matter (see Fig. 441). Under the microscope, the 
* Quart. Geol. Jour.,vol. ix., p. 58. 
t Dawson, Air-Breathers of the Coal in Nova Scotia. Montreal, 1863. 
