HERPESTES. 177 



The skull of S. smithii is closely allied to those of S. pcdlidus, H. jerdonii, 

 and H. maccarthice, but it differs from the first in its wider brain-case and the 

 slightly greater width between the orbits and the longer alveolar border ; but the 

 most marked features are the basal breadth of the skull and the character of the 

 palatal margin of the posterior nares, which is concave from behind forwards, and not 

 marked by any median ridge or backwardly projecting spine, as sometimes occurs 

 in S. pcdlidus. The hinder portion of the suture of the nasals and the whole 

 of the premaxillary suture have disappeared. The orbit is enthe. The skull is 

 large for the dimensions of the animal. The last lower molar has two prominent 

 anterior cusps, with the margin of the posterior division of the tooth somewhat 

 divided. 



The skeleton of the type of tliis species is in the British Museum, and having 

 carefully examined it, I am in a position to state that it in no way differs generi- 

 cally from the skeletons of Ileryestes auropimctatus and S. maccarthice. A 

 rudimentary, hypapophysial ridge is developed on the cervical vertebrae, becoming 

 very obscure on the last segment, but in the fifth the posterior nodular end is 

 partially bifid. The spinous processes of the dorsal vertebrse are long and strongly 

 developed. On the transverse process of the sixth dorsal a small tubercle is de- 

 veloped, which gradually becomes transferred to the back of the process and nearer 

 to its root, so that on the eleventh vertebra it occupies the position of an anapo- 

 physis. It is distinctly bifm'cated on the twelfth, and is a true anapophysis on 

 the thirteenth vertebra, whilst it suddenly disappears on the fifth lumbar. Mam- 

 miUary processes begin to show themselves on the eleventh dorsal segment. There 

 are in all 26 ribs, and the vertebral formula is C. 7, D. 13, L. 7, S. 3, C. 29=59. 

 The primary transverse processes of the caudal vertebrae are strongly developed to 

 the seventh, beyond which they become more and more transferred to the hinder 

 extremity of the centrum, and are all but lost on the twelfth segment. The 

 secondary transverse processes begin to develope, as in all Serpestes, on the anterior 

 border of the primary transverse processes, and on the part of the centrum imme- 

 diately in front of them, and gradually more forwards, at last occupying the anterior 

 portion of the centrum, and disappearing after the primary transverse processes 

 have been lost. The spinous or neural ridge exists as far backwards as the tenth 

 caudal vertkbra, but, beyond that, it becomes reduced to a posterior eminence on 

 the bodies as far as the seventeenth segment. The remains of the zygapophyses 

 and metapophyses can be detected as far as the twenty-first segment of the tail. 

 The caudal bodies increase in length to the fourteenth vertebra, beyond which 

 they more quickly diminish in diameter than in length. Chevron bones begin as 

 a pair of nodules on the second vertebra, but, between the third and fourth, 

 they are developed into an osseous canal, and retain this character to the ninth 

 vertebra, where they are again resolved into two pieces and gradually revert to 

 their original, nodular character. The shoulder and pelvic girdles conform essen- 

 tially to the structure of these parts in Serpestes, as also the limb bones and the 

 sternum. 



