4 STUDIES OF TASMANIAN CETACEA, 



thus pretty clearly showing that yellow sided dolphins 

 are immature animals. Individually, the young male here 

 under description manifested two, irregularly oval, white 

 marks in the region of the tail, but otherwise conformed 

 to the adult tinting, except in the matter of yellow replac- 

 ing white upon the under parts — as already stated. 



Food. 



During the dissection of the adult animal the stomach 

 was turned out, and found to contain a fair amount of 

 semi-digested food, and an enormous number of the horny 

 beaks of cuttlefish, also a few worms. The immature ani- 

 mal had apparently been feeding upon Echinoderms, as 

 large quantities of Spatangus spines were found, and were 

 the only undigested elements met with. 



Ribs and Scapula. 



As the scapulas are frequently misplaced in articu- 

 lated dolphins' skeletons, a measurement was made prior 

 to the removal of the scapulae of the immature animal to 

 exactly fix its position. The numerical result was — from 

 tip of beak to anterior rim of scapula = 21^ inches when 

 the arm was at a right angle to the line of the body. As 

 a guide to articulation, therefore, the hamular process 

 should just overlap the edge of the first rib. In the 

 matured dolphin the dorsal ribs (five) that reach the 

 sternum, were retained in natural articulation, to set at 

 rest the exact positions of the tubercula and capitula in 

 each pair of ribs. It is an excellent plan to keep at 

 least one such thorax in every comparative collection as 

 it forms a court of appeal when cetacean skeletons are 

 in process of mounting. 



External Mea.xnrtmrnts 



