462 ELEPHANTIDJE. 



SUBUNGULATA, 

 Suborder PROBOSCIDEA. 



Nose produced into a long flexible proboscis, with the nostrils at 

 the end, and serving as a prehensile organ. Incisors forming 

 conical tusks, often of large size in male animals, never exceeding 

 one pair in each jaw and confined to the upper jaw in living forms. 

 No canines. Molars large, more or less elongate, with flat parallel 

 sides and transversely ridged. Limbs stout ; radius distinct from 

 ulua and tibia from fibula. Feet massive, each with 5 toes, the 

 outer more or less rudimentary. Stomach simple. A capacious 

 caecum. Testes permanently abdominal. Uterus bicornuate. 

 Placenta non-deciduate, zonary. Mammae two, pectoral. Brain 

 of low type, the cerebellum being entirely behind the cerebrum 

 and uncovered by it. 



The Proboscideans, although highly specialized, are of lower 

 grade than other Ungulates. By many naturalists elephants and 

 their allies are regarded as having affinities with Bodents. 



A single family containing but one living genus. Of extinct 

 forms a large number are found in later Tertiary beds, and from 

 the Upper Miocene, Pliocene, and Pleistocene of India no fewer 

 than 7 species of Elephas are known, besides 8 of the allied genus 

 Mastodon and 2 of Dinotherium. 



Family ELEPHANTID^E. 



Genus ELEPHAS, Linn. (1766). 



~, c." ( ,m. 5=^ The incisors (tusks) are preceded by 

 milk-teeth, shed at an early age, and have enamel only on the tips 

 before these are worn away, the remainder of each tusk consisting 

 of solid dentine. The molars come into use successively from the 

 back of the jaw, and are worn away and shed in front, not more 

 than one, or portions of two, on each side of each jaw being in 

 wear at once ; the three anterior, which come first into use, being 

 regarded as milk-molars not succeeded by premolars, whilst the 

 last three are true molars. All are composed of enamel-covered 

 plates or ridges of dentine with cement between. The number of 

 transverse ridges increases from the first to the last molar. 



Skull large, high, and globular, the greater portion consisting of 

 cancellous tissue containing air-cells which communicate with the 

 nasal passages. The brain is small, and lies far back between the 



