REMAINS IN THE COAL-FORMATION OF NOVA SCOTIA. 
639 
Length of mandible .... 
55 
femur. 
. . . . P5 
55 
humerus (?). 
. ... P3 
55 
vertebra. 
55 
rib .. 
There are five teeth in 2 millimetres. 
Under the microscope the hone shows elongated cells and a somewhat fibrous 
structure, and there is much cartilage associated with it. The teeth are composed of 
radiating tubes of ivory of remarkable coarseness, and with distinct lateral canaliculi ; 
but the coarse tubes do not reach the surface to which only their terminal canaliculi 
extend, and there appears to be a thin superficial layer of dense and brilliant enamel 
having externally a microscopic vertical striation. 
The above characters are taken from two specimens approaching each other in 
dimensions. A third specimen was of much smaller size, and had longer and more 
slender palatal teeth. It was originally set apart as a second species, under the name 
S. acutidentatum; but as the bones secured are few, and it may possibly be a young- 
individual of the present species, I have thought it best to leave it undescribed in the 
meantime. 
6. Hylerpeton Daivsoni, Owen (Plate 41, figs. 62 to 85). 
[Owen, Journal of Geological Society, vol. xviii., p. 241. Dawson, ‘Air-breathers 
of the Coal Period/ p. 55. ‘Acadian Geology/ p. 380.] 
The specimen on which Owen founded this genus and species was obtained by me 
in 1861. Unfortunately it consisted of only a few fragments of bone, the principal of 
which was a mandible, with some of the teeth remaining, and a fragment of a maxilla. 
The trees subsequently examined have afforded bones belonging to four additional 
individuals, and enable the following description to be given. 
Bones of skull slightly striated, but not sculptured as in Dendrerpeton . Lower jaw 
with distinct ascending ramus or coronoid process, a feature not known in any other of 
these amphibia, but observed by Cope in his genus Brachydectes, which may be allied 
to Hylerjpeton, but is known only by the jaws and teeth. Teeth, twelve in each ramus 
of the mandible, bluntly conical, slightly striated at the apex. Pulp-cavities large and 
longitudinally striated at the sides, though the teeth are not folded. Maxilla furnished 
with similar teeth, one of which near the front is larger than the others. Palatal teeth 
numerous, small and conical, with a few large teeth at the sides. 
Vertebrae short, cylindrical, well ossified, with well developed zygapophyses and 
neural spines ; ribs strong and much curved, with well developed division of the 
proximal ends; pelvis imperfect, but apparently large, with broad ilium. 
Humerus half the length of the mandible ; radius half as long as humerus; femur 
mdccclxxxii. 4 n 
