DOLPHINS. 113 



In the next Case are the skeleton and some skulls of another 

 freshwater Dolphin, Inia geoffrensis, from the Upper Amazon and 

 its tributary streams, and also of a very remarkable species, Pon- 

 toporia blainvillii, from the estuary of the B-io de la Plata, of very 

 small size, with exceedingly long and slender jaws and the most 

 numerous teeth of any mammal, sometimes as many as 60 on each 

 side of each jaw, or 240 in all. Both of these have some rela- 

 tionship with the Platanista, although in many characters they 

 approach the next group, or true Dolphins. 



Family DELPHINID.E. 



A very numerous group, composed of the animals commonly 

 called Dolphins and Porpoises, although some of the larger mem- 

 bers are also dignified by the name of Whales. Skeletons of most 

 of the genera are exhibited, and also a large series of skulls (those 

 of the smaller species being in the Wall-Cases at the end of the room 

 nearest the door). There are also stuffed specimens of many 

 species, and papier-mache models of others, showing very well the 

 external form and colour of the animals when fresh. 



The principal genera are : 



Delphinus. The true Dolphins, Bottle-noses, or, as they are more 

 commonly called by seafaring people, " Porpoises,"" are found in 

 considerable abundance in all seas. They are all among the 

 smaller members of the Order, none exceeding 10 feet in length. 

 Their food is chiefly fish, for the capture of which their long, 

 pointed beaks, armed with numerous sharp-pointed teeth, are well 

 adapted; but some appear also to devour crustaceans and moll usks. 

 They are mostly gregarious, and the agility and grace of their 

 movements in the water are constant themes of admiration to the 

 spectators of the scene when a " school of Porpoises " is observed 

 playing round the bows of a vessel at sea. The old genus is 

 now much subdivided Lagenorhynchus, Tursiops, Prodelphinus, 

 Solatia, Steno, Cephalorhynchus, being names applied to its various 

 sections ; Delphinus being now generally restricted to the common 

 Dolphin of the Mediterranean, D. delphis, and its immediate allies. 

 This species is met with, though not frequently, on the English 

 coast; a stuffed specimen from Cornwall being shown in the 



