i?6 A GUIDE FOR THE STUDY OF ANIMALS 



2. Dorso-lumbar vertebrce, vertebrae with small lateral 

 processes. 



3. Sacrum, the ninth vertebra, bearing extra long lateral 

 processes or " arms." 



4. Urostyle, the last vertebra, lying in the median line, 

 a long, slender, blade-like bone, really formed by the fusion 

 of several vertebrae. 



C. Vertebra : — 



1. Centrum, the solid, nearly circular portion. 



2. Lateral process, one of the paired projections, extend- 

 ing outward on either side. 



3. Neural spine, the single projection, extending toward 

 the dorsal side. 



4. Neural arch, formed largely by a connection between 

 the lateral process and the neural spine. The arch above 

 and the centrum below inclose the neural canal. 



D. Pectoral, or Shoulder, Girdle : — 



1. Sternum, the "breastbone," extending along the 

 median ventral line. 



2. Coracoid, a heavy bone extending from the sternum 

 sidewise to support the arm. 



3. Clavicle, the " collar bone," a light bone in front of 

 the coracoid. 



4. Scapula, the "shoulder blade," a broad, thin bone 

 which arches around to the dorsal side. 



E. Pelvic, or Hip, Girdle : — 



1 . Ilium, a long, slender, curved bone, with its mate unit- 

 ing to form an inverted " wishbone " ; it is joined to .the 

 sacrum. 



2. Pelvis, the region of the socket at the junction of 

 the ilia. 



