FALCONEK MASTODON AND ELEPHANT. 287 



Another very fine detached specimen of the last milk-molar, lower 

 left, with the first four ridges worn, shows also eight principal 

 ridges, besides talons. Posteriorly it is denuded of cement; the 

 ridges are wide apart, and the enamel very deeply grooved, as in 

 Crag specimens, the grooving being strongly marked below, and 

 disappearing towards the apices of the ridges. Hence a correspond- 

 ing difference in the edging of the enamel plates, according to the 

 stage of detrition. This specimen is very ferruginous, and might 

 pass for a " Crag " fossil. The dimensions are : — 



Inches. 

 Length of crown ........................ 4*7 



Width at first ridge 1-5 



Width at fifth ridge 1-85 



Height of enamel plate at fifth ridge ...... 2-3 



Another smaller-sized detached specimen of the same tooth 

 shows only seven principal ridges, with front and back talons, 

 proving that there may be a difference of one ridge, more or less, 

 in the ridge-formula of the last lower milk-molar. Taking the 

 data furnished by the young jaws, upper and lower, and using .v as 

 a symbol for the talons, the "ridge-formula" of the milk-series 

 in E. (Loxod.) meridionalis is proved to be thus — • 



Milk-molars. 

 x^x + ocQx -f x9>x 



x^x -j- xQx -f x'Sx 



This specimen is also very ferruginous and " Crag "-looking. 



d. Lower true Molars. — The antepenultimate true molar is re- 

 presented by a finely preserved detached tooth of the right side, 

 having the crown and fangs complete. It presents eight ridges, 

 with the usual talons. The large undivided anterior fang supports 

 two ridges, and the anterior end bears the pit of pressure against 

 the preceding tooth, proving the crown to be entire. The first four 

 ridges are worn low, exhibiting thick enamel plates, more or less 

 grooved or channelled exteriorly, and thus presenting a spurious 

 appearance of crimping, but unplaited, on the inner border. The 

 disk is but slightly expanded in the middle, and without angularity. 

 The last three ridges have only the tips of the digitations abraded, 

 showing very distinct rings of thick enamel, free from grooving or 

 plaiting. The ridges are all well in relief from the cement, and 

 wide apart. The fangs supporting the last four ridges are con- 

 fluent into a common shell. The principal dimensions are — 



Inches. 



Length of crown 5-5 



Width of ditto at second ridge 2-2b 



Width of ditto at seventh ridge 2*6 



Height of crown at seventh ridge 2-3 



This tooth, though of larger dimensions and with a much greater 

 relative width than the last milk-molar, retains the same number of 

 plates. 



The same tooth is presented, in situ, in a mutilated left ramus 



VOL. XXI. PART I, X 



