IGO 



SKETCH OF THE HISTORY OF MAMMALIA. 



horny layer of the gum, which passes on to the surface of 

 each plate, and the pulp is therefore the secreting organ 

 of the internal layer of coarse elastic fibres. The number 

 of plates composing each row is from 300 to 400, and, the 

 palate being oval, the longest are those situated in medio ; 

 those towards the muzzle and near the entrance of the 

 throat being consequently the shortest. The longest of 

 these laminae often measure 15 feet and upwards in length ; 

 and the abbreviation anteriorly and posteriorly is gradual. 

 Each plate, as we have said, is fringed, and the filaments 

 of the fringe are very numerous, and fill up the cavity 

 of the mouth sufficiently to form a strainer. The lower 

 juw is arched boldly outwards on each side, so as to form 



105. — Inside Jaws of Greenland Whale. 



