CETACEA. 61 



e. Skull with the maxillary bones bent up in front of the 

 blowers, and forming a vault. The teeth compressed. 

 The paddles fan-shaped, truncated at the end. Plata- 

 nistina. 



17- PLATANISTA. 



My thanks are due to Dr. Richardson of Haslar, to Mr. Bright- 

 well and the Committee of the Norwich Philosophical Society, 

 and to Mr. Bell, for allowing me to have at the Museum for 

 comparison the specimens of these animals in the collections un- 

 der their care ; and to Mr. Owen and the Council of the College 

 of Surgeons, and the Council of the Zoological Society, for per- 

 mission to examine the skulls of the different species of this 

 family in their Museums. 



A. Jaws tapering, the symphysis of the lower jaw short, not 

 half the length of the jaw. Dor sal fin generally distinct. 

 Pectoral fin ovate acute. Marine. 



a. Upper jaw toothless; lower jaw with only one or two teeth 

 on each side, often hidden in the gums. Beak of skull 

 keeled on each side, the keel being sometimes large, and 

 forming an elevated reflexed wing on each side. Hyperoo- 

 dontina. 



Hyperoodontina, Gray, Zool. Ereb. fy Terror, 24, 25. 

 Diodonea, pars, Rafin. Anal. Nat. 60, 1815. 



1. HYPEROODON. 



Upper jaw toothless ; lower jaw with a small, conical, acute, 

 rudimentary, moveable tooth, in a cavity under the gums, on 

 each side of the front part. Blowers linear, transverse, sub- 

 lunate. 



Hyperodon, Rafin. Anal. Nat. 60, 1815. 



1. Uranodon, Illiger, Prod. 143, 1811. 



Nodus (sp.) edentulus, Wagler, Nt S. Amph. 34. 

 Orca, Wagler, N. S.Amph* 34. 



2. Hypodon, Haldeman. 

 Chenocetus, Eschricht, Danish Trans. 

 Cetodiodon, Jacob, Dublin Phil. Journ. 

 Diodon, Lesson, Ouvr. Buffbn, i. 124. 



Anaruacus, Lacep. ; Dumeril, Z. A.; Rafin. Anal. Nat. 61, 



1815; Gray, Zool. Ereb. fy Terror. 

 Ancylodon, Illiger, Prod. 142, 1811; Oken, Lehrb. Nat-ury. 



673, 1815. 



