66 THE TRUE DOLPHIN. 



direction till opposite the dorsal fin, where the body 

 is thickest. From a hand's breadth or more behind 

 the dorsal fin, the body rapidly diminishes to the 

 tail, and on the lower surface, the same rapid di- 

 minution takes place from beyond the anus. The 

 tail is composed of two strong lobes terminating in 

 points, which give a beautiful crescent shape, to 

 the extremity of this powerful instrument for 

 swimming. 



In examining the anatomical details of this ani- 

 mal, one can not fail to be struck with the singular 

 appearance of the bones forming the lateral fins. 

 We find a shoulder blade, an arm bone, bones of 

 the forearm, wrist and fingers, all so modified as, 

 when covered by the skin, to resemble nothing so 

 much as a fin, yet so obviously analogous to the 

 same bones in the human subject, or in other ani- 

 mals, as to be recognised almost at a glance. The 

 construction of the blow-hole, or breathing ap- 

 paratus, is also well worthy the peculiar attention 

 of the observer who may have an opportunity of 

 examination, on account of its remarkable excel- 

 lence of adaptation, and the delicacy of its con- 

 struction. 



The colour of the true dolphin, is of a black or 

 blackish green on the upper surface, and on the 

 inferior parts, of a light gray or whitish. There is 

 below the eye, on each side, a whitish ray or blaze 

 extending towards the humeral fins. 



