342 ME. W. H. FLOWER ON THE OSTEOLOGY OF THE SPERM-WHALE. 



liom the fore part of the spine, altogether above the junction of the laminae at the roof 

 of the neural arch, and their upper margin is 11" above the top of the body. There 

 are not any corresponding processes on the hinder edge of the spine, as in Platanista. 



The Caudal Vertehrw are twenty-four in number, of which twelve or more appear, by 

 the form of their inferior surfaces, to have supported chevron bones, although but ten 

 of these bones were sent with the skeleton. 



As is usual in this extensive region, the characters of the different vertebrae vary 

 o-reatly. The first differs but slightly from the last lumbar vertebra. The centrum is 

 more regularly circular when seen from the end, but rather higher than broad, the keel 

 is no lono-er distinct, the sides are less hollowed, and on the hinder edge of the under 

 surface are two distinct articular facets for the first chevron bones. The transverse 

 processes are short, horizontal, and rounded at the ends, as in the lumbar region ; the 

 spinous process is sHghtly sliorter, the metapophyses higher upon it, and the neural 

 canal more contracted. The body of this vertebra is slightly larger than that of the 

 last lumbar. In the succeeding seven there is very little change in respect to size ; after- 

 wards the diminution is more rapid. The reduction in the size of the centrum of the 

 thirteenth as compared with the twelfth, and of the fourteenth as compared with the 

 thirteenth, is so extraordinary that, unless there were abundant evidence to the con- 

 trary, one might be tempted to suppose that several vertebrae had been lost from each 

 interval. The fifteenth, again, is considerably smaller than its predecessor. Then follow 

 two of almost equal size, after which a gradual and steady reduction takes place down to 

 the terminal vertebra. 



Fig. 10. 



Fourth caudal vertebra, without the epiphysis. 



The great irregularity in the diminution of the caudal vertebrae will be best appre. 

 ciated by a reference to the table of the weights of the different members of the series 

 given at p. 328. 



