ELEPHANT AND MASTODON. 



Ill 



molar — inferred from the comparatively small size of the jaw indicating 

 a young adult, from the small size of the tooth and from the one behind 

 it. The seco7id is broken off about the middle and is entirely in germ, 

 no jDart of it having emerged above the border of the alveolus ; it shows 

 the greater part of six ridges ; the mammillEe are few in niunber and of 

 large size and with very thick enamel, nearly as thick as in the stego- 

 dons : one mental foramen is visible. This is a highly instructive 

 specimen, both as regards the middle-aged dentition and as showing the 

 transition into the Stegodons, the enamel being very thick and the ridges 

 comj)aratively low. 



Dimensions. 



Inches 



Length of specimen ........ 13-5 



Ditto of anterior molar ........ 6' 



Width of crown in front ....... 2' 



Greatest width at fifth ridge ....... 3- 



Length of fragment of posterior molar ..... 4'7 



Width of base of crown of last ridge ..... 3"5 



Height of enamel plate of fourth ridge . , . . . 2-9 



The specimen is entirely cleared of matrix, but is weathered into 

 the reddish ochreous colour common in many of the Ava specimens. 

 Unluckily there is no information as to whence it came. 



No. 22. Elephas{Lox.) pla7iifrons. — Fine fragment of the lower jaw, 

 comprising nearly the whole of symphysial portion of both sides, the 

 beak of which is slightly broken off: the whole of the horizontal ramus 

 and greater part of ascending ramus right side ; the condyle and 

 coronoid apophysis alone are wanting. Two molars are contained in 

 the jaw. The anterior one is well worn, showing about six ridges and 

 a heel ; the three anterior ridges being ground down into one common 

 disc, and the three posterior also worn down close to the base of the 

 crown. The discs of wear are wide, and a little expanded in the 

 middle, the enamel thick and with very little tendency to plaiting. The 

 posterior molar shows six ridges emerged from the alveolus, the two 

 anterior of which are sUghtly abraded, the rest being qriite intact and 

 covered over with a large quantity of cement. It is not apparent how 

 many ridges more are contained in the back part of the alveolus. Both 

 molars exliibit the characteristic form of Elephas planifrons in a well- 

 marked manner. 



Dimensions. 



Inches 

 21-0 

 7-7 

 7-5 

 6-8 

 3-6 

 5-5 



Extreme length of fragment ...... 



Height of jaw to the surface of anterior ridge of first molar 



Ditto behind to third ridge of second molar 



Length of front molar ....... 



Greatest width of crown of ditto ..... 



Length of emerged part of second molar . . . i . 



Length of diastema from anterior border of penultimate molar 



to upper edge of extremity 'of symphysis .... 7" 



The characters of the anterior j^art of the jaw differ very considerably 

 from those of the existing Indian Elephant. In the latter, the diastema 

 descends nearly vertically from the anterior extremity of the molar, 

 the beak is very short and the outline of the t\vo rami is rounded, 

 whereas, in the fos;41 the diastema descends obliquely forward at an 

 acute angle with the inferior border of the ramus, entailing a long 



