MAMMALIA. 
149 
the lower jaw ; having small conical teeth concealed in the up¬ 
per gums ; tail straight and conical; a longitudinal eminence on 
the back, above the anal region ; upper part of the body slate- 
coloured, slightly spotted with white ; belly bluish-white. Forty- 
six to sixty feet long. Inhabits the Northern Seas. 
Sub-Genus 2 .— Physeter. — Lacepede. — Spiracle orifice situ¬ 
ated at the end, or near the end, of the upper part of the muzzle ; 
having a dorsal fin. 
Physeter microps .— The Small-Eyed Cachalot. 
Lower jaw with 21 arched, slightly turned back teeth, on 
each side ; dorsal fin large, straight and pointed ; pectoral fins 
broad ; eyes small; sixty to eighty feet long. Inhabits the 
Northern Seas. 
Genus 7. — Balcena. — Linnaeus . 
Generic Character. — Without teeth; upper jaw keel-shaped, 
provided on each side with transverse horny lamina} or whale¬ 
bone, slender, serrated, and attenuated at the edges ; orifices of 
the spiracles separated, placed near the centre of the upper por¬ 
tion of the head; some species with a dorsal fin; and nodosities 
on the backs of others. 
Sub- Genus 1.— Baljena. —No dorsal fin. 
Balcena mysticetus. — The Common Whale. 
Plate XXXIV. fig. 6. 
Body thick, tail short; without boss on the back ; upper jaw 
with about seven hundred transverse laminae. From eighty to 
one hundred feet long. Inhabits the Atlantic and Polar Seas. 
Sub-Genus 2 — Balenoptera. —With dorsal fin. 
Balcena boops. — The Jubarta. 
Nape of neck elevated and round ; with longitudinal folds 
m 3 
