ANOMALOUS DOLPHINS 299 



will be, if confirmed, another small point of likeness 

 to the Sirenia. The sternum itself is not unlike that 

 of a Manatee ; it is a single bone, oval in outline, with 

 a deep anterior notch. In the whalebone whales the 

 sternum also consists of a single piece. 



The scapula, unlike that of Platanista, is not 

 aberrant, but conforms to the ordinary dolphin 

 pattern. Both acromion and coracoid are long. 

 The humerus is unusually long (a clearly unspecialised 

 character), and longer than the radius or ulna, the 

 reverse being the case in other Cetacea. The 

 hand has five carpals besides the pisiform. The 

 formula of the phalanges is this: I, i. II, 5. Ill, 4. 



IV, 2. V, 2. 



The teeth of Inia are from 104 to 132, the formula 

 being ^-^ 



O 2O to 32* 



The teeth (as in Stend] are markedly rugose on 

 the crowns. They also show a very important 

 character (in the approach to the complex teeth of 

 terrestrial carnivores) in the presence of a supple- 

 mentary lobe to the hinder teeth. 



The only species is Inia geoffrensis* with the 

 synonyms : Delpkinus amazonicus, Spix and Martius ; 

 Inia boliviensis, d'Orbigny ; D. geoffroyi, Desmarest. 



This dolphin frequents the Amazons, and reaches 

 an extreme length of eio-ht feet. It has a striking 



<~> O ^j 



coloration, as well as a considerable amount of 

 variability, which, it may be incidentally remarked, 

 throws doubt upon other identifications of Cetaceans 



* DE BLAINVILLE, Nouv. Did. Hist. Nat., ix., p. 151. 



