MAMMALIA. 523 



centre, gradually diminishing towards its caudal extremity, wbicli 

 is luniform, with two points ; head obtuse ; lips double ; no 

 external ears, or appearance of a neck ; eyes surmounted by 

 a cartilaginous crest; anterior extremities in the form of pal- 

 mated fins. 



Stellerus horealis. — The Northern Stellera. — Head 

 round; without tusks or canines. Twenty-three feet long. 

 Inhabits northern parts of the South Sea and North America. 



Family II — Cetacea. 



Teeth generally pointed, sometimes obtuse, all of one kind, 

 and placed on the margins of the jaws ; sometimes with trans- 

 verse corneous laminse in the arch of the palate, in place of 

 teeth ; two anal mammae ; spiracles or nostrils opening at the 

 top of the head, for the ejection of water ; tongue smooth ; with- 

 out hairs, eye-lashes, or mustachios. 



Tribe I. — Small-Headed Cetacea. 



Genus 4. — Delphinus. — Liiinaus. 



Generic Character. — Teeth all shaped like canines, com- 

 pressed, and notched on their cutting margins ; varying in num- 

 ber from 200 to none ; jaws more or less protruded in form of 

 a beak ; aperture of spiracles luniform ; an adipose dorsal fin, 

 with sometimes a longitudinal dorsal fold of skin ; tail hori- 

 zontally flattened and bifurcated. 



Sub-Genus 1.— Delphinus — Cuvier. — Muzzle elongated in- 

 to a moderate beak; large at the base, point rounded ; jaws pos- 

 teriorly widened, having tlieir edges provided with immerous 

 teeth ; a single dorsal fin. 



Delphinus delphis. — The Dolphin. — Plate XXV. fig. 2.— 

 Described, vol. III. p. 382. 



Sub-Genus 2. — Phoc^na. — No beak; muzzle short and con- 

 vex ; jaws with numerous teeth ; having a dorsal fin, 



Delphinus grampus. — The Grajifus.— Described, vol. I J I. 

 p. 382. 



Sub-Genus 3. — DEL-emsovjERVs,—Li(ceperh. — Head ob- 



