20 



THE MAMMALIA. 



The IjAUGER and Weasel Family [Mustclida). Except 

 a single species all the Carnivora belonging to 

 this family have a single large tubercled tooth in 

 each half of the upper, and two molars in each 

 half of the lower jaw. 



Badgers {McUda). Plantigrade carnivores with 

 thickset clumsy body, short feet, and highly 

 developed anal glands. 



Martens {Mariida). Mostly digitigrade, with long 

 and even wormdike body, frequently retractile 

 claws, and usually a long bushy tail ; the upper 

 tubercled tooth small and transversely placed, 

 the upper carnassial sharp and with a horizontal 

 process in front. 



Otters {Lntrida). Aquatic Mustelida with long but 

 stout cylindrical body, short webbed feet, and 

 flattened tail. 



THE SEALS {Pinnipedia). 

 Aquatic carnivores with feet converted into fiippers, 

 spindle-shaped body, complete dentition, and zonary 

 placenta. 



The Eared Seals {Ola?-ida). Provided Avith ex- 

 ternal ears. 



The True Seals {F/wcida). Without external ears 

 and with short limbs. 



The Walrus {Trichechiis). Armed with tusks. 



WHALES AND DOLPHINS {Cetacea). 



Fishdike carnivores Avithout hind-limbs, and having the 

 fore-lirnbs converted into flippers, the tail in the 

 form of a horizontal fin. The nostrils (blow-holes) 

 are situated on the summit of the forehead; the ill- 

 developed lips have no moustache hairs, the skin 

 is naked, the placenta diffuse, and the teats situated 

 far back in the abdominal region. 



Toothed Whales {Denticete). 



Dolphins {Ddphinida). AVith a larger or smaller 

 number of uniform teeth in both jawsj feed ex- 

 clusively on fishes. 

 The Sperm Whale Family {Physderida). With 

 fully developed teeth only in the lower jaw. 

 Whale-bone Whales {Mysticete). 



Fin-backed Whales {BalceriopUrida). 

 Right Whales (Balcenida). 



THE SEA-COWS (Sirenia). 



Fish-like herbivora without dorsal or ventral fins, with a 

 small head and distinct neck, thick lips set with 

 tactile hairs, molars with broad crowns, nostrils at 

 the end of the muzzle, and pectoral teats. 



THE ELEPHANTS {Proboscidca). 



Large animals whose nose is prolonged into a proboscis 

 which serves as a prehensile and tactile organ, with 



column-like legs, and feet with five toes united into 

 a mass and covered with flattened hoofs; the upper 

 incisors mostly in the form of tusks; no canines; 

 compound molars; jilacenta zonary. 



THE ODD-TOED UNGULATES {Perissodactyld). 



Hoofed animals mostly of large size, usually with an odd 

 number of toes on both pairs of feet, the middle 

 toe being the one that continues the axis of the 

 leg. The thighdjone has a third trochanter; denti- 

 tion complete; stomach simple; teats abdominal or 

 inguinal; placenta u.sually diffuse and composed of 

 separate cotyledons distributed over the whole sur- 

 face of the ovum or embryo. 



The Lock-badger Family {Hyracida). With four 

 toes in front, three behind, and certain rodent- 

 like characters in the dentition. 



The Tapir Family {Tapirida). Composed of animals 

 somewhat resembling large pigs, but distinguished 

 by the possession of four hoofed toes in front, 

 three behind, and a short mobile proboscis. 



The Rhinoceros Family {Nasicomia). Composed 

 of a single genus of huge clumsy animals, with 

 three toes both in front and behind, one or two 

 formidable horns composed solely of horny matter, 

 and a peculiar dentition. 



The Horse Family {Equida). A family repre- 

 sented at the present day by only a single well- 

 marked genus, with shapely bod)', long slender 

 legs terminating in only a single digit (the middle 

 one), but comjjrising also a number of extinct 

 forms with a greater number of digits both on 

 the fore- and hind-feet. 



THE EVEN-TOED UNGULATES {Artiodactyla). 



Hoofed animals of ^ery variable size, almost always with 

 an e\en number of toes, which are arranged about 

 two parallel axes running through the middle line 

 of the second and fourth digits. The thigh-bone 

 has no third trochanter. The stomach shows a 

 tendency to subdivision. The originally complete 

 dentition gets gradually specialized and reduced. 

 The teats are abdominal and inguinal; placenta 

 diffuse. 



Non-ruminant Artiodactyla {Polydactyla). With more 

 than two digits. 



The Hippopotamus or River-horse Family {Obesa). 

 Composed of the single genus Hippopotamus, 

 consisting of huge clumsy animals, with very thick 

 hides, four toes both on the fore- and hind-feet, 

 and a highly remarkable dentition. 



The Pig Family {Siiida). With large and thick but 

 tapering head terminating in a snout, the end 



