36 



THE SKELETON OF THE HORSE 



processes. Those in the middle of the series are the most typical and present the 

 following features: 



1. The bodies are short and constricted in the middle. The ends are expanded 

 and have articular surfaces which are not strongly curved. On the upper part of 

 each side are anterior and posterior costal facets (Fovea costalis cranialis, cau- 

 dalis), which, with those of adjacent vertebrae, form sockets for the heads of 

 the ribs. 



2. The arches are small. Their posterior notches are relatively large and are 

 often converted into foramina. 



3. The articular processes are small. The anterior pair are in fact represented 



Anterior articular process 



Posterior articular process 

 Transverse processes 



Facets for tubercles of ribs 



Facets for heads of ribs 

 Intervertebral foramina 



Facet for head of rib ^«ce< for tubercle of rib 



Fig. 13. — Third, Fourth, and Fifth Thoracic Vertebr.e of Horse, Lateral View. (After Schmaltz, Atlas 



d. Anat. d. Pferdes.) 



only by two oval facets on the anterior part of the laminae which face almost directly 

 upward. The posterior pair spring from the base of the spinous process; their 

 facets face almost directly downward. 



4. The transverse processes arc short, thick, and tuberous at the free end. 

 Each has a facet (Fovea transversaria) for articulation with the tuberosity of the 

 rib which has the same serial number. 



5. The spinous process is large, narrow, and slopes upward and backward. 

 The anterior ))order is thin, the posterior wider and furrowed. The summit is 

 expanded and rougli. 



The first thoracic vertebra is easily recognized by the following specific charac- 

 ters: The body is wide and flattened dorso-ventrally. In front it has a head like 



