160 ADDENDUM. 



ileum, and strong ischiac and pubic bones. There are also broad 

 scapular, and probably sternal bones, but crushed and imperfect. 

 Few of the ribs remain, and these apparently only the smaller 

 ones, as compared with other skeletons of which I have portions. 

 Several of the bones of the limbs remain in sufficiently good 

 preservation to allow of measurement of their size. I am thus 

 enabled to give the following dimensions of parts of the animal. 



Total length of skull, 1-fa inches. 



" breadth « at the orbits,* 2 " 



Length of humerus, 1-fV " 



« " ulna, 1 " 



" « femur, 1 " 



« " rib, -ft » 



" " eleven vertebras in series, 2 1 3 2 - " 



It would seem from these dimensions that the head was broad, 

 and the trunk slender; the anterior limb, including the foot 

 half as long again as the head, and the posterior limb rather 

 smaller or shorter than the anterior. It would thus appear that 

 while the general form of the body was not unlike that of Meno- 

 branchns, the limbs were much larger, and must have carried the 

 trunk without allowing any part of it to touch the ground, as 

 would also seem to have been the case from the footprints found 

 in the coal-formation beds, and the size and form of the toes of 

 which make it likely that they belonged to this animal. 



The limb-bones, though thin-walled and often crushed, evi- 

 dently had broad articulating surfaces ; and in the base of the fore- 

 limbs particularly, were large and strong in proportion to the di- 

 mensions of the head and vertebral column. 



The large size of the fore-limb I suppose to have been related 

 to a habit of walking or standing in shallow water, with the snout 

 in the air, in the manner of newts, and the more rapid movements 

 of the creature were probably performed by the tail. It is inter- 

 esting to observe that in Hylonomus the proportions of the limbs 

 were reversed — the hind limbs being much larger than the fore 

 limbs. 



From the relative dimensions of the bones, as compared with 

 those of other specimens in my possession, I presume that this in- 

 dividual was three-fourths grown, and I doubt if its total length 

 much exceeded one foot. 



* Perhaps increased by flattening. 



