462 PROFESSOR J. AJ^DEESON ON THE 



in. lin. in. lin. 



Anterior extremity of symphysis to extremity of process of 



2 



lower jaw 11^ to llf 



Anterior extremity of symphysis to condyle 10„10 



Anterior extremity of symphysis to coronoid process ... II5- „ 11 



Length of alveolar surface 7^ „ 7-| 



Depth through coronoid process 4^ „ 4^ 



Depth from base of corono-condyloid notch 3| „ 3 



Skeleton (figs. 8-19). — The most striking features of the skeleton are the great size 

 of the skull, the very short tail, and the united tibia and fibula. The vertebrae are 

 distributed as follow: — seven cervical, fourteen dorsal, six lumbar, four sacral, and 

 fourteen caudal. The column from the atlas to the sacrum has two well-marked curves. 

 From the first vertebra as far as the seventh cervical the curve is downwards and back- 

 wards, and then upwards and backwards as far as the second lumbar vertebra, from 

 which the column is directed downwards and backwards. 



Spinous processes. — In the vertebrae generally the spinous processes are not well 

 developed, if we except the axis (in which it constitutes a prominent, laterally com- 

 pressed, antero-posteriorly expanded, halbert-shaped plate) and the second dorsal (in 

 which it forms a long, slender, backwardly projecting process), with the processes of 

 the third, fourth, fifth, and sixth vertebrae only feebly developed. The process of the 

 first dorsal is very small ; and from the third to the seventh cervical it is represented 

 by only a minute spine, most marked in the last of the neck-segments. In the twelfth 

 to the fourteenth dorsal this process partakes, more or less, of the character it assumes 

 in the lumbar region, where it is an antero-posteriorly expanded plate directed forwards, 



overlapping the vertebra in front of it. The spinous ridge of the sacral vertebrae is a 

 low, thin plate, with its anterior margin directed forwards, retaining faint indications of 



the low original spines. 



Hyperapophyses begin to show themselves in the thirteenth dorsal, and become more 



marked as they are traced backwards to the third lumbar, in which they attain their 



maximum development, but beyond which they diminish in size to the last lumbar. 

 Metapophysial processes are first found on the second dorsal, beyond which they 



increase in size as far back as the fourth lumbar. Traces of these processes are also 



observable in the sacral vertebrae, and they may be detected in the caudal vertebrae up 



to the seventh. 



Anapophyses first appear in the twelfth dorsal, but they are most strongly developed 



in the second and third lumbar, beyond which they rapidly diminish, disappearing in 



the last vertebra of the loins. 



Transverse processes. — These processes are rather small in the second to the seventh 



cervical vertebrae ; and each, in one specimen before me, is capped with a small ossicle. 



The pleurapophysial plate appears first as a well-marked bony ridge running from the 



