VEETEBEAL COLUMN 77 



its long spinous process, by the presence of cephalic articular pro- 

 cesses, and by the long concave area on the dorsal surface of the 

 transverse process lying between its tip and the cephalic articular 

 process. 



The side of the body has a costal half-facet at each end. The 

 transverse process is not so large, and the area between its tip and the 

 dorsal edge of the cephalic articular process is more sloping and less 

 concave. The costal facet on its ventral surface is large, but smaller 

 and shallower than that on the preceding vertebra. 



The pedicles and laminae have greater cephalo-caudal diameters. 



The spinous process is usually longer than any other spinous 

 process on the vertebral column. In the mounted skeleton it appears 

 much higher, because the second vertebra itself is placed somewhat 

 above the first. 



The caudal articular surfaces are in the ventral third of the maxi- 

 mum height measured on a line drawn perpendicular to the ventral 

 surface of the body. 



The Third Thoracic Vertebra (Figs. 50, 51, 52) differs from 

 the second in possessing no distinct cephalic articular processes, the 

 cephalic articulating surfaces appearing on the flattened, cephalic part 

 of the dorsal surface of the lamina?. They therefore face dorsally, 

 and are separated by a deep, triangular emargination in the edge of 

 the lamina?, but are not so widely separated as the corresponding 

 articular surfaces of the second vertebra. 



The transverse processes are slightly shorter and their cephalo- 

 caudal diameters greater than those of the second vertebra, and 

 their origin is more dorsal on the pedicle. The costal articular facet 



o 1 



is only slightly concave, and does not occupy the entire cephalo-caudal 

 width of the ventral surface. The cephalic surface of the transverse 

 process is narrow and depressed. On the dorsal surface is an oblong, 

 elevated, flattened area which faces dorsally and laterally and corre- 

 sponds with the surface described in the vertebra? which follow as the 

 end or lateral surface of the process. The long diameter of this area 

 is oblique, passing from the dorsal side ventrally and toward the tail. 

 Caudal and medial .to this area the dorsal surface is excavated and 

 slopes ventrally and toward the tail, meeting the ventral surface at a 

 sharp, emarginate, caudal edge. 



The laminae have a greater cephalo-caudal diameter and a narrower 



