378 



THE CARBONIFEROUS SYSTEM. 



similar to that in the last species. No doubt a more perfect specimen 

 would show many points of difference between these species, not now 

 appreciable ; but in the meantime the very different form of the teeth 

 is a sufficient distinction. In H. Lyelli these are conical and pointed. 

 In the present species they are of a peculiar wedge shape — their 

 diameter transversely to the jaw being the greatest at the base, while 

 at the top they are sharpened to an edge. The peculiar form of the 

 intermaxillary teeth may also serve as a distinctive character, though 

 those of H. Lyelli are not yet known. The form of the vertebra 

 would further seem to indicate different proportions of body. On the 

 whole, while this species is in all probability generically related to 

 the last, it is certainly specifically distinct. Its habits and food may 

 have been similar, but its dental apparatus was stronger and more 

 formidable. 



Hylonomus Wymani, Dawson. 



This is the species of Hylonomus originally detected by Professor 

 "Wyman in the specimens brought from the Joggins by Sir C. Lyell 

 and myself. Remains of several additional individuals have since 

 been found, but no skeleton approaching to completeness. I shall 

 describe this, the most diminutive of the reptiles of the Nova Scotia 

 coal, with the aid of the fragments represented in Fig. 146, most of 

 which are almost microscopic in size. 



Fig. 146. — Hylonomus Wymani, Dawson. 



(a) JIandible and maxilla; nat. size. (/) Bones of limb and pelvis; nat. size and mag. 



(6, c, d) Portions of the same; magnified. (g) Bones of foot; enlarged, 



(e) Rib; nat. size and magnified. (h) Scales; enlarged, 



(i) Vertebrae ; nat. size and magnified. 



The skull seems to have been much of the same form as in Hylonomus 

 Lyelli, but very thin and delicate, so that all the specimens hitherto 

 found are crushed and fragmentary. The maxillary and mandibular 

 bones are furnished with teeth which are bluntly conical in form, and 

 in the latter bone seem to be confined to its front part, or to be very 

 small posteriorly. They are thus much fewer in number than in the 

 species last named. I have been able to make out only twenty-two 



