L06 DR. ('. W. ANDREWS ON THE 



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tli.-it it differs n tittle Less than thai of Elephas from the ordinary proportions of the 

 mammalian skull. At the same time the facial region is almost exactly as in Elephas. 

 The maxillsB by reason of the more braohydoni character of the cheek-teeth are not 

 so deep as in the elephant, hut are still very large owing to the great size of the 

 molars and to their mode of replacement from hehind ; anteriorly the maxilhe send 

 forward processes beneath the premaxillai. thus helping to support the tusks, of the 

 alveoli of which they may form the hinder edge. In the zygomatic arch thejugal 

 perhaps extends slightly farther Forward than in Elepliax, at least ventrally. In 

 short, the skull of Tctvabclodoii is essentially similar t<» that of Elephas. 



Figs. 6 and 7. — Skull of TetradelodoTt a/iigjatidens, Civif.r sp. Lower and Middle Miocene. Europe. 



The Mandible (figs. 8 and <)). — It is in the mandible that the most remarkahle 

 divergence from Elephas is found. The symphysis! region is enormously elongated 

 and its upper surface deeply concave from side to side, forming a spout-like channel, 

 the sides of which are formed by the edentulous alveolar border. The channel is 

 narrow posteriorly but widens out in front, and its concavity is continued forward 



