The body seems to have possessed an interclavicle and ventral scutellæ. Above it was, apparently, clothed with small tubercles and horny scales, and to have had cuticular pendants like those of _Dendrerpeton_. An additional species of this genus was apparently indicated by some fragmentary remains, but Dawson thought best not to describe them as such, since they might indicate only a young individual of the present species. Length of mandible 1.5 cm. Length of femur 1.5 cm. Length of humerus (?) 1.3 cm. Length of vertebra 3-5 mm. Length of rib 1 cm. There are 5 teeth in 2 mm. [Illustration: Fig. 18. Skeletal elements of _Smilerpeton aciedentatum_ Dawson, from the Coal Measures of Nova Scotia. (After Dawson.) a, shaft of femur, × 2; _b_, intermaxillary and teeth, × 25; _c_, sections of teeth, × 25; _d_ and _e_, palatal teeth, × 25; _f_, femur, × 2; _g_, rib, × 2; _h_, palate; _i_, caudal vertebræ; _j_, long palatal tooth, × 25; _k_, bony scale.] =Genus HYLERPETON Owen.= Owen, Quart. Jour. Geol. Soc. London, XVIII, p. 241, 1862. Dawson, Amer. Jour. Sci. (3), XII, p. 443, 1876. Dawson, Phil. Trans. Roy. Soc. London, 1882, pt. II, p. 634. Dawson, Proc. and Trans. Roy. Soc. Canada, 1895, p. 74. Dawson, Air-breathers of the Coal Period, p. 55, pl. vi, figs. 32-46, 1863. Body stout, with strong limbs. Mandibular and maxillary teeth strong, not numerous, grooved at apex. Palatal teeth numerous, and some of them large. Thoracic plate broad. Abdominal scales pointed or oat-shaped. Type: _Hylerpeton dawsoni_ Owen. =Hylerpeton dawsoni Owen.= Owen, Quart. Jour. Geol. Soc., XVIII, p. 241. Dawson, Air-breathers of the Coal Period, p. 55, 1863. Dawson, Acadian Geology, p. 380. Dawson, Phil. Trans. Roy. Soc. London, 1882, pt. II, p. 639, pl. 41, figs. 62-85. Dawson, Proc. and Trans. Roy. Soc. Canada, 1894, XII, p. 74. Type: Specimen No. 3061-4, Peter Red path Museum, McGill University. There are also specimens, Nos. R 441 and 442, in the British Museum (393, pt. IV, p. 225). (Plate 7.) Horizon and locality: Coal formation at the South Joggins, Nova Scotia. 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 the Nova Scotia fauna, but observed by Cope in _Brachydectes_. Teeth, 12 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, conical, with a few large teeth at the sides. [Illustration: MOODIE PLATE 11