MAMMALIA. 627 



Mostly there are two teeth, but sometimes also (M. A. HENDEIKSZ .and C. 

 MULDER Alg. Konst- en Letterbode voor 1831, i Deel, bl. 305, 306, 338 

 341, W. THOMPSON Ann. and Mag. of Nat. Hist. xvn. 1846, p. 152) 

 four teeth at the fore part of the lower jaw, concealed in the gum; 

 besides these some smaller teeth in addition lie also concealed in both jaws 

 (EscHRiCHT Untersuck. iib. die Wallthiere, a. 37). This cetacean has occa- 

 sionally been cast ashore on the coasts of Great Britain and Holland, 

 otherwise it resides in high Northern latitudes, and usually keeps far from 

 the shore ; it is captured at the Faroe Islands, where it is named Dogling. 

 The food of Hyperoodon consists chiefly of Cephalopods (Loligines), of 

 which the horny beaks heaped up by thousands or sometimes within each 

 other were found by VROLIK in the specimen dissected by him. 



As SCHLEGEL has remarked, to this sub-genus ought also to be referred 

 Delphinus mtcropteriis Cuv. (F. Cuv. Cetac. PL 8, fig. i, DUMORTIEB, 

 Mem,, de VAcod. royole de Brux. xn. 1839, avec 3 P^)> from which Del- 

 phinus Sowerbyi DESMAR., Physeter bidens SOWERBY does not seem to differ, 

 in the opinion of ESCHRICHT also, according to whom this last species is the 

 male of Delph. micropterus. DUVERNOY forms from these species, which 

 he contends are distinct, his genus Mesodiodon; see Ann. des Sc. not., 

 3ieme Se"rie, Tome xv. 1851, Zool. pp. 5, 71; compare also GERVAIS, 

 ibid. XIV. pp. 5 17. Here belong fossil species from the tertiary beds 

 named Crag, which were united by CUVIER in one genus under the name 

 of Zupkius. 



Platanista F. Cuv. Teeth conical, projecting from the gums, 

 numerous in both jaws. Blow- hole a longitudinal fissure. Snout 

 produced, compressed. Dorsal fin depressed, remote. Pectoral 

 fins subtriangular, broad at the posterior margin. 



Sp. Delphinus gangeticus LEBECK, Der Geselhchaft naturforsck. Freunde zu 

 Berlin new Schriften, in. 1801, s. 280 282, Taf. II., Delphinus rostratus 

 SHAW, F. Cuv. Cetac. pp. 251 257, PL 8, fig. 2 (PI. 18, figure of the 

 skull), ESCHRICHT Om Gangesdelphinen, in Kongel. DansTce Videnslc. Selsk. 

 Skr., 5te Raeklce, Natur. og matkem. Af deling, 11. Bd. 1851, pp. 347 387, 

 with 3 pi. This dolphin, which lives in the mouths of the Ganges, becomes 

 7' long, and is distinguished not only by its long sword-shaped snout com- 

 pressed laterally, but also by its eyes being so small that, on a superficial 

 view, it might be supposed to be entirely blind. The blow-hole has a form 

 quite unusual amongst cetaceans. In the rising ridges of the superior 

 maxillary bones the skull resembles in some degree that of Eyperoodon. 



Delphinus auctor. Several conical teeth projecting from the 

 gums in both jaws. Blow-hole transverse, lunate, concave forwards. 



The Dolphins. Amongst these the smallest cetaceans are found, of which 

 only a few species attain more than ten feet. It is the only division of this 

 family that is numerous in species ; some are found in all seas, a few also 

 in rivers. They are very voracious, and swim with great velocity. In 

 some species the head extends forwards into a narrow snout (sub-gen. 

 Delphinus Cuv., Rhinodelphis WAGN.). Here belongs Delphinus Delphis 

 L., LACEP. Cetac. PL 13, fig. i, BLUMENB. Abb. naturhist. Gegenst. No. 95, 



402 



