56 



PROF. ^Y. B. BENHAM ON THE OSTEOLOGY 



[Feb. 4, 



. In the lower jaw of my specimen there are 1 3 teeth on each 

 side; but in the Napier skull I find 15. The former is the 

 number given by Wall and Kreflft (3) ; the latter number is 

 attributed to this whale by de Blainville and by Van Beneden & 

 Gervais; while Flower & Lydekker, in their text-book on the 

 Mammalia (first edition), give the number as from " 9 to 12." 



The Vertebral Column. 



Turning to the vertebral column, there are, in addition to the 

 cervical mass of seveia fused vertebrae, in which all trace of 

 the separate vertebrae is absent, except of the 1st, 2nd, and 7th, 

 46 free vertebrae, of which 13 are thoracic, 9 are lumbar, 23 are 

 caudal, of which the anterior 13 bear cheAT.'on-bones. In this 

 enumeration I have followed Flower (on Physeter) in regarding 

 as the first caudal that vertebra which carries at its hinder end 

 the first che\Ton. 



It may be useful to give a svimmary of the formula of the free 

 vertebrae according to previous authors \ 



With regard to the number of thoracic vertebrae, there thus 

 appears from the accounts to be some slight discrepancy. Von 

 Haast has already pointed oiit that the total number of vertebrae 

 " 52," given by Wall, is due to an error in addition of the 

 constituent vertebrfe. Van Beneden & Gervais state (p. 351) that 

 " whereas Wall describes 14 thoracic vertebrae and 14 pairs of 

 ribs ^, we only count 13 on our figure." They suggest that perhaps 

 the small 14th rib, being free and independent of the vertebral 

 column, had disappeared during the preparation of the skeleton 

 {C. macleayi), and they fovind only 13 thoracics in the Japanese 

 specimens described on p. 515. 



In the Parakanui skeleton there are only 12 pairs of complete 

 ribs articulated with the vertebrae ; but amongst the debris of the 

 macerating-pan I found a small bone (PI. II. figs. 2, 3), 

 measuring only 37 mm. in length by 9*5 mm. in greatest breadth. 



1 Flower & Lydekker give C. 7 ; Th. 13 or 14 ; L.+C. 30 : total 50 or 51. 

 * Wall found only the ribs of the right side. 



