64 DELPHINID^. 



1. Inia Geoffroyii. 



Inia Geoffroyii, Gray, I. c. pp. 226, 393 ; Synops. Whales 8f Dolph. 



p. 4; Flower, Trans. Zool. Soc. vi. p. 87, t. 25, 26, 27 (skeleton). 

 Delphinus amazonicus, Spix, Reise in Brasil. t. iii. pp. 1119 and 1113, 



fig. 34 (bad). 

 Inia Geoffrensis, IfOrbigny, in Ann. Mus. Paris, vol. iii. p. 23; Ger- 



vais, Osteog. Get. t. xxxii. 



Inhab. Brazil, river Amazon. 



" The number of the teeth in the different specimens of Inia exa- 

 mined shows a considerable range of variation, presuming that they 

 all belong to one species. In the one now described there are 

 r 2- l 27 ~^^^' ^ e l ar S er specimen in the British Museum, 

 from Ega, has ^~^_ = 109, and also two minute rudimentary teeth 

 in the gum behind the last in the left maxilla. In the smaller skull 

 from the same place there are ^^-=110. In the skull in the 

 Paris Museum, brought by D'Orbigny, there are, according to Ger- 

 vais, 5§Ef3 = 132; but in the type specimen in the same museum, 

 taken from Lisbon, the number is given by De Bainville as 

 |^?=104. In the Berlin skull the teeth are ^=|?=131. Von 



26 — 26 33 — 32 



Martius, in his diagnosis of the species, gives ^~^ 8 = 114.'' — Flower. 



Family 10. DELPHINID^. 



Delphinidre, Gray, I. c. pp. 228, 393 ; Synops. Whales $■ Dolph. p. 4 ; 

 Flower, Trans. Zool. Soc. vi. p. 113. 



Head beaked. Teeth in both jaws, conical or compressed, per- 

 manent, without any internal lobe, occupying nearly the whole 

 length of the jaws. Back rounded, with a falcate dorsal tin ; rarely 

 absent. Skull with the maxilla expanded over the orbit, and more 

 or less turned up on the edges. 



" Costal cartilages firmly ossified. Posterior ribs losing their capi- 

 tular articulation, and only uniting with the transverse processes of 

 the vertebrae by the tubercle. Anterior (2-6) cervical, in most, an- 

 kylosed together. Pterygoid bones short, thin, involuted to form, 

 with a process of the palatine bone, the outer wall of the postpala- 

 tine air-sinus. Numerous teeth in both jaws (Monodon excepted), 

 sometimes deciduous. Symphysis of mandible short or moderate, 

 never exceeding one-third the length of the ramus. Bones of the 

 skull not raised into a distinct crest behind the anterior nares. 

 Orbit of moderate size. Lachrymal bones not distinct from the 

 jugal. Pectoral limbs varying much in form and size. Dorsal fin 

 usually present." — Flower. 



