534 



3174. An upper molar of a Horse. 



In the former edition of the ' Osteological Catalogue ' it is stated, that this tooth had the 

 following inscription, in Mr. Hunter's handwriting, attached to it : 



"A Horse's tooth of the under jaw ; had ground out the tooth above it ; the wound mor- 

 tified, and the horse died." P. 125. No. 870. 



Hunterian. 



3175. The skull of a Horse. 



In this specimen the middle third of the left ramus of the lower jaw has been entirely 

 destroyed by the ulcerative absorption. This would seem to have proceeded with rapidity, 

 since the molars of the corresponding part of the upper jaw have not been protruded beyond 

 their usual position. 



Purchased. 



The following, to No. 3181 inclusive, are parts of the same skeleton of a Horse (Equus 

 Caballus) : 



Hunterian. 



3176. The atlas. 



The anterior articular cavities do not meet below : the diapophysial ridges are much more 

 produced than in the Camel, and bend down, forming large concavities. The vertebral arte- 

 ries twice pierce the base of each process, which is also perforated by a canal leading to the 

 neural canal, anterior to which the neural arch is perforated on each side. The hypapophysis 

 developes a strong tubercle. 



3177. The axis. 



The neural spine is a strong but low rugged ridge, which bifurcates posteriorly, and sub- 

 sides upon the zygapophyses. The diapophyses are short and triangular, with their bases 

 perforated by the vertebral artery. The centrum of the atlas has coalesced with that of the 

 axis to form the ' odontoid process.' A strong ridge on the under part of the centrum leads 

 to the hypapophysis. The posterior articular surface of the centrum is deeply excavated. 



3178. The third cervical vertebra. 



The pleurapophysis is developed below the arterial canal, and extends forwards, outwards 

 and downwards. The neural spine has subsided to a low rough ridge. The hypapophysial 

 ridge and tubercle are well marked, as are also the anterior convexity and posterior concavity 

 of the centrum. The inner surface of each neurapophysis is pierced by a small canal in the 

 same place and direction as that which transmits the vertebral artery in the Camel ; but the 

 vertebral artery traverses the base of the transverse process in the Horse, as in most other 

 mammals. 



3179. The three middle lumbar vertebrae. 



The anterior end of the centrum is slightly convex, the posterior slightly concave. A met- 

 apophysial ridge projects from the outside of each anterior zygapophysis. There is a hyp- 



