168 



error in the universally assumed character of mammals, which Dau- 

 benton and Cuvier first applied, with the sole exception above no- 

 ticed of the Sloth, which, however, still remains the exception to the 

 number, while it corroborates the principle of coupling or pairing 

 the cervical vertebrae, which is of considerable use in unravelling 

 the cranial vertebrae, and which De Blainville speaks of as still un- 

 intellio-ible " to those who have been unable to elevate themselves 

 to this kind of questions" (the signification of the skeleton transcen- 

 dentally considered) " partly on account of the nature of their 

 minds, and partly from the want of proper and sufficient subjects of 

 contemplation." 



In this view of the cervical vertebrae, there was no examination 

 of what are known as floating or cervical ribs, fii'st pointed out and 

 described by Vicq d'Azyz in the Memoirs of the Academy of Paris for 

 the year 1774, and which lately, Professor T. Bell of King's College, 

 London, has described in the case of the Bradypus. This class of ribs 

 ought to be regarded as quite difl:erent from the thoracic ribs ; and 

 there was a beautiful example exhibited on the table, which the 

 kindness of Professor Goodsir enabled the author to shew to the 

 Society, and which forms part of a series collected and described by 

 Dr Knox, in the London Medical Gazette, some years ago. In va- 

 rious classes there are similar ribs, quite unconnected with, and dif- 

 fering from, the thoracic ribs, which are rather homotypes of the sty- 

 loid process of the temporal bone, and possibly of the lower floating or 

 the 10th, 11th, and 12th, or abdominal ribs. (?) The consideration of 

 these, in the next part of the communication, with the exposition of 

 the cianial vertebrae, will form a subject for a farther communica- 

 tion. 



Having demonstrated that the 7th rib is attached to the 7th ver- 

 tebra in the Mammal class, as in the Monkeys ; the Carnivora, as far 

 as examined ; the Elephant, Hog, and Horse, among the Pachyder- 

 matu ; the Deer, Elk, Giraffe, Camel, Ox, Sheep, among the Rumi- 

 nants ; and the Dugong, Porpese, and Whale, among the Cetacea, — 

 the only exception being the Seal and Walrus, in the specimens of 

 the Bai'clay Museum of the Royal College of Surgeons of Edin- 

 burgh ; and also having assigned a sufficient cause for the abnormal 

 situation of the 1st rib in Man on the 8th vertebra, instead of be- 

 tween the 7th and 8th, — the enumeration of the cervical region will 



