572 



PROBOSCIDEA. 



d 



FIG. 293. Upper molar of Elephas africcinus. d dentine, 

 e enamel, ; cement (from Owen). 



menb., in the Pleistocene of Eur., As., and Amer. The skin had a thick 

 woolly covering, as is shown by the frozen carcases occasionally met 

 with in X. Siberia, where the tusks (somstimss from 10-12 feet in length) 

 are found in considerable numbers, affording ivory for export, and also by 

 contemporary drawings scratched on mammoth ivory. The cause 

 of the comparatively recent extinction of the mammoth is doubtful ; 

 it may have been due to the decay of the forests in which it lived. E. meli- 

 tensis Falcon., a pigmy species found in caves in Malta. 



Extinct 

 genera, Stego- 

 don Falc., 

 tusksinupper 

 jaw, with en- 

 amel band ; 

 grinders com- 

 posed of 6-12 

 1 o w cusped 

 ridges, with 

 cement i n the 

 v a 1 1 e y s , 

 Miocene and 



Pliocene of Asia. Dinotherium Kaup, i y c p ^ m , the grinders 

 being bilophodont (except ml, which has 3 ridges), and all in function at 

 once, the premolars have milk predecessors ; the extremity of the mandible 

 is deflected and the tusks (lower incisors) project downwards (Fig. 295); 

 cranium depressed with but few air-cells : in size it surpassed living ele- 

 phants ; M. and U. Miocene of Eur. and As. Mastodon Cuv., i 



1 or 



c Jj p f m I ; u. incisors as large tusks with bands of enamel, 1. incisors 

 variable, never large, sometimes absent ; grinders with mammillated 

 ridges and scanty cement (Fig. 294), the anterior three grinders some- 

 times replaced, Miocene and Pliocene of Old World, in the Xew World 

 it survived until the 

 Pleistocene. Tetrabelodon 

 Cope, dentition, i \ c % 

 p | m f , the upper in- 

 cisors are tusks and the 

 lower are procumbent 

 teeth in close contact ; 

 there appear to have 

 been 3 deciduous molars, 

 the last two of which 

 were replaced ; the pre- 

 molars were shed early ; 

 the premolars and molars 

 are brachyodont and bi- 

 or tri - lophodont, the 



ridges being tuberculated, and m3 has a tuberculated talon ; the sym- 

 physial region of the mandible is much elongated. Miocene and Pliocene 

 of Eur. Asia, Afr., X. Amer., extending into the Pleistocene in Amer. 



Palaeomastodon Andrews, from the Upper Eocene of Fayum, Egypt ; 

 dentition i \ c fj p f m |, the upper incisors are tusks, the lower pro- 

 cumbent and spatulate ; the premolars and molars very similar to those 

 of Tetrabelodon except that all were in use at once in the usual way, 



FIG. 294. Oblique side and crown view of the last 

 upper molar of Mastodon arvernensis (from Flower and 

 Lydekker). 



