328 



1. HYPEROODON. 



Forehead convex. Blower transverse, slightly convex forward in 

 the middle, and bent back a little at the ends. Gape short, only as 

 long as the short beak. The eyes near and the ears far behind the 

 gape. The crests of the maxillary bones thin and wide apart above. 

 The beak of the skull descending forwards. The hinder edge of 

 the skull as high as the crests. Lower jaw rather ciu-ved. Blade- 

 bone triangular, angles very acute ; the acromion very broad at the 

 end, directed downwards, and the coracoid upwards, the upper edge 

 with a prominence (see Cuvier, Oss. Foss. v. 318. t. 24. f. 23). The 

 bones of the arm short ; fingers short (Cuv. 318). Cei'vical vertebrae 

 united, all anchylosed together. — 3Ius. Hull; Graves, Edinh. Phil. 

 Journ. 1830, 59. 



1. Hyperodon, Bafn. Anal Nat. 60, 1815 ; Gray, P. Z. S. 1864, 239. 

 Hyperoodon, Lacep. ; Cuvier, Oss. Foss. v. 327. t. 24 ; Gray, Cat. Cdac. 



P. M. 1850, 61 ; Duvernoi/, Ann. Sci. Nat. xv. 44, 1851 ; Rousseau, 

 Mag. Zool. 1858, 205. 

 Chenodelphinus, EsehricM, Isis, 1844, 805. 



2. Uranodon, Pliger, Prodr. 143, 1811. 



Nodus (sp.) edeutulus, Wagler, N. S. Amph. 34. 



Orca, Wagler, N. 8. Amph. 34. 



Anarnacus, Lacep. ; Dumeril, Z. A. ; Pafiv. Anal. Nat. 61, 1815 ; Gray, 



Zool. Ereb. 8f Terror. 

 Ancylodon, Illic/er, Prodr. 142, 1811 ; 0];en, Lehrh. Nalury. 673, 1815. 



3. Hypodon, Ilaldeman. 

 Chenocetus, E-ehrieht, Danish Trans. 

 Cetodiodon, Jacob, Dublin Phil. Journ. 

 Diodon, Lesscni, (Enrr. Buffon, i. 124. 

 Monodon spurius, O. Fain: 

 Heterodon, sp., Desmarest, Mamm. 

 Delphiuus, sj)., Desmarest, Mamm, 



4. PDiodypus, Rafin. Anal. Nat. 60, 1815 (no type or char.). 



In the British Museum there is the mass of the cervical vertebrae 

 of a young Hyperoodon Butzlcopf. It is unfortunatelj- not in a good 

 condition, the edges being Avorn, and the ujiper lateral processes of 

 the hinder cervical vertebrae being broken off. It agrees in general 

 shape with the cervical vertebrae of Lagenocetus ; but the upper cones 

 formed of the united neural arches are not so high, nor keeled in 

 front ; the principal difference is in the seventh cervical vertebra 

 and its lateral processes and neural arch being as completely united 

 to the other vertebrae as any of the rest, they all seven forming a 

 single bony mass. 



The canal of the spinal marrow is very large, but otherwise like 

 that of Laejenocctus ; but the hinder part of the canal is higher, being 

 as high as wide above, and its width is rather greater thanjialf the 

 width of the body of the seventh cervical vertebra. 



According to Voigt and Thompson the ends of the blowers point 

 forward ; Dale, Baussard, Doumet, Bell, and Jenyns describe them 

 as pointing backwards; Desmarest and others assumed the latter as 



