484 DR. J. V. HAAST ON MESOPLODON FLOWERI. [June 6, 



are missing ; but they are also strongly laterally compressed. There 

 are nine chevron bones, of which the last is missing. "With the 

 eleventh vertebra the second series of the caudal vertebrae begins, 

 which in form greatly resemble those of the New-Zealand Epiodon. 



Bibs. 



There are ten ribs on each side, of which seven have two articu- 

 lations and the last three only one. 



The first is the shortest of the whole series with the exception of 

 the last ; it is also the broadest. 



There is scarcely a sign of an articular process for its articulation 

 with the seventh cervical vertebra, and only a very slightly marked 

 articular surface for the transverse process, both being indicated by 

 a small indentation on the edge of the head of the rib. The second 

 rib has the same flattened form as the first ; it is longer, and both ar- 

 ticulating processes are better-defined. From the second to the 

 sixth rib, they gradually lengthen, after which they diminish again 

 a little until we reach the tenth, which is the shortest of the whole 

 series. The third, fourth, fifth, sixth, and seventh ribs have all well 

 defined articulating processes and nearly the same form, flattened at 

 and near their head, after which, for nearly one third of their total 

 length, they become more constricted and assume a prismoid shape, 

 after which they flatten and gain again in breadth, their terminal end 

 being, however, narrower. The eighth and ninth ribs, which have 

 only one articulating process for their junction with the transverse 

 process, have the same form as the foregoing if we imagine their 

 heads and necks removed. The tenth rib is flattened throughout ; 

 it has also only one articulating surface, and at its posterior end 

 runs out to a point. 



The greatest length of each rib, measured in a straight line, is : — 



Sternum. 



The sternum consists of four principal segments, of which the 

 fourth and smallest is separated into a left and a right portion by a 

 division in the centre, which apparently would not have disappeared 

 by ankylosis in a still more aged state of the skeleton. 



The first segment is the largest and broadest ; it is without a keel, 

 but is well rounded towards the central line. There is a deep exca- 



