416 



ANATOMY OF VEKTEBRATES. 



281 



forming one mass like a ' cervical sacrum' in the true Whales 

 {Balatna, fig. 159,c), small Cachalots {Euphijsetes)-' the Grampus,^ 

 the Porpoise : the neural arches of the axis and following cervicals 

 are confluent in most. The cervicals thus give a firm support to 

 the large head which has to overcome the resistance of the water 



when the swift swimmer is cleav- 

 ing its course through that ele- 

 ment. The characters defining the 

 succeeding vertebras, applicable to 

 comparisons of species and re- 

 cognition of range of variation, 

 appear to be : — the support of free 

 ribs ; the presence of transverse 

 processes formed chiefly by coa- 

 lesced pleurapophyses, fig. 141, t?; 

 the articulation of haemapophyses, 

 fig. 282, h, to the centrum, ib. c. 

 Thus, in a large British Dolphin 

 {Delphinns tursio), the skeleton of which I prepared (and to take 

 the bones from the carcase is almost essential to certainty as to 

 number of ribs and haemal arches), there 

 are sixty vertebrae. Of the seven cervical 

 the first two only are anchylosed : thir- 

 teen vertebrae support free ribs suspended 

 to terminally expanded diapophyses, fig. 

 281, ^; then follow twenty-nine with trans- 

 verse processes only, as in fig. 14,1, d: the 

 thirty-third vertebra from the skull first 

 supports a haemal arch, but in that and 

 the two following vertebrie the piers or 

 ' haemapophyses ' are small and ununited : 

 the complete arch, as in fig. 282, h, is 

 continued, diminishing, to the last six 

 vertebrae, which consist of the centrum 

 only, much depressed. Thus, between 

 the thirteenth dorsal vertebra and the 

 first with haemapophyses, there are thirteen which might be 

 termed ' lumbar,' fig. 159, D, cd, but hold the place of lumbar and 

 sacral in other Mammals {Megatherium, e.g., fig. 279, L, s). A 

 sacrum is never indicated by vertebral confluence in Cetacea, and 

 only obscurely by the position of the pelvic rudiments, fig. 159, 

 63, 64, loosely suspended below. In the Delpli. tursio a metapo- 



Dorsal vertebra. Whale. 



282 



Caudal vertebra. Whale. 



' XCIII-. 



xvnr. p, 520, fig. 214. 



