298 OSSIFEEOUS CAVES OF MALTA. 



True Molars. — Of the antepenultimate true molar (m. 1), 

 there is no perfect specimen in the collection. But as in all 

 the species of Elephant and Mastodon this tooth invariably 

 repeats the composition of the last milk molar, we have no 

 difficulty in fixing the normal number of its ridges to have 

 been eight, besides talons. In E. antiquus the number is ten, 

 and in the Mammoth and Indian Elephant twelve. 



Of the penultimate true molar there is no entire specimen 

 of a lower tooth ; but we have the upper beautifully preserved 

 in PI. XI. figs. 2 and 2 a, and exhibiting a crown distinctly 

 composed of nine ridges besides a front and a hind talon. 

 In the African Elephant the same tooth is commonly made 

 up of nine ridges. In E. antiquus the normal number is 

 twelve, while in E. primigenius and E. Indicus it amounts to 

 sixteen. 



Of the last true molar (m. 3) there are fortunately speci- 

 mens both of the upper (PI. XI. figs. 1 and 1 a) and lower 

 (PI. XII. figs. 4 and 4 a) jaws ; and although the portion 

 supported on the anterior fang is wanting in both, as that 

 constantly corresponds in all the species of Elephant with 

 what is borne upon the same fang of the penultimate, we 

 have little difficulty in restoring the missing part of the 

 teeth. The upper molar (PI. XI. figs. 1 and 1 a) exhibits 

 the remains of ten ridges, and adding two for the part cor- 

 responding with the anterior fang we get a complement of 

 twelve ridges for the crown of the last molar. In the 

 African Elephant the same tooth in the upper jaw ranges 

 about ten ridges, and in the lower from ten to twelve. In 

 E. antiquus the number is sixteen, and in E. primigenius 

 and E. Indicus they reach twenty-four. 



From the above data the ridge-formula of the molar-series 

 is deduced to have been thus : 



This formula at once brings the small Zebbug species 

 within the subgeneric group of the Elephants, which I have 

 called Loxodon, along with E. Africanus ; the affinity of the 

 fossil to the existing species is further clearly indicated by 



behind ; the enamel also is much more 

 plaited and the crown much broader ; it 

 has seven ridges and talons, the anterior 

 talon being worn low, and the bounding 

 shell of enamel not quite complete in 

 front. No. 21,655 has also seven ridges 

 'and talons, all of which are more or less 

 worn ; it is covered with an enormous 

 mass of cement. 



Zebbug. E. antiquus. 

 m.m. 3. m.m. 3. 



18,810. 21,655. 



Length of crown . . 2'2 255 2-9 

 Width at second disc - 7 "85 - 9 

 Greatest width behind 7 1-4 1-3 

 Height of crown at 



seventh ridge . . "7 1"4 — ' 



[Ed.] 



