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fluent below with a short, thick, broad, subquadrate haemapophysis, h. The short neck 

 of the rib terminates in a small obtuse end without any distinct articular surface : this 

 end seems to have been imbedded in the ligamentous mass between the seventh cer- 

 vical and first dorsal vertebrae : the short neck quickly expands into the shaft of the 

 rib : a small elliptical surface, fig. 1 a, n", on the upper part of the neck, is continued 

 at its outer end into the larger convex surface upon the upper part of the tubercle, 

 d": from the middle of the anterior border of this surface a strong ridge is continued 

 down the outer surface of the rib to its hinder border. The sternal end of the haem- 

 apophysis, fig. 1 b, presents a large subtriangular surface, slightly concave in one 

 direction, slightly convex in the other, adapted to a similar single concavo-convex 

 surface on the side of the much developed and modified haemal spine called 'manu- 

 brium sterni.' 



This bone (Plate XI. figs. 1, 2, 3) is of an oval or cordiform figure, with a pro- 

 minence on each side near its inferior truncated apex, below the lateral articulations, 

 hp, for the first pair of sternal ribs. The outer surface is principally concave length- 

 wise, and is sculptured by the impressions of the coarse aponeurotic structures which 

 have been adherent to it in the living animal : a short median longitudinal ridge pro- 

 jects from its lower part. The inner surface is chiefly convex, but is very irregular. 

 At its upper half a strong median prominence divides the shallow rough depressions, 

 cl, for the attachment of the clavicular ligaments : these depressions are deepest above 

 the costal articulations which are supported on well-marked triangular prominences. 

 Between these prominences the bone is rather concave. A strong rough tuberosity 

 projects below the lower angle of the costal surface. The contracted inferior end of 

 the manubrium terminates in an oval convex articular surface,*', for the second ster- 

 nal bone. There are no articular surfaces for the haemapophyses of the second dorsal 

 segment. 



The skeletal segment (Plates I. C?\ IV. fig. 7) in advance of the first of the 

 dorsal series is reduced to its centrum and neural arch ; both pleurapophysis, 

 haemapophysis and haemal spine are absent ; and its remaining anchylosed elements 

 constitute the 'seventh cervical vertebra' of Descriptive Anatomy. This is most 

 remarkable for the great development of the neural spine (Plate IV. fig. 7, ns), 

 which exceeds that of the first dorsal vertebra: the summit is similarly expanded 

 and flattened above (Plate IV. fig. 5, ns 7) ; but the anterior margin is still more 

 produced, forming a low angle about half-way down the spine (fig. 7, ns). The 

 anterior zygapophyses are more remote from each other than in the first dorsal, and 

 their articular surfaces are chiefly supported by the inner side of the base of the 

 metapophyses, figs. 5, 7 w», which are here well developed and more distinct from the 

 diapophyses, d, fig. 7, than in the dorsal region. The diapophyses, figs. 5 &c7,d, are 

 strong, rugged, stand out from the sides of the neural arch, and terminate in rough 

 truncate ends. The posterior zygapophyses (figs. 6 & 7, *') are slightly convex. 



In the sixth cervical vertebra (Plates I. Ce; V. figs. 5 & 6) the spine, ns, is much 



c 2 



