PLATE IX. 



Fig. 1. First dorsal rib. 



Fig. 2. Second dorsal rib. 



Fig. 3. Third dorsal rib ; one-fourth natural size. 



Figs, la, 2a, 3a, their upper articulations. 



Figs, lb, 2b, 3b, their lower articulations; one-half natural size. 



c", articular surface on the head for the centrum ; n", articular surface on 

 the neck for the neurapophysis ; d", articular surface on the tubercle for 

 the diapophysis ; V, anterior condyle for sternum, s", posterior condyle 

 for sternum ; pi, pleurapophysial part, h, hsemapophysial part, of rib. 



