284 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



Inches. 



Length of crown about 9*0 



Width of ditto at first ridge 3-2 



Width of ditto at base of fifth 4-01 ratio of 



Extreme height of fifth 5-4 J 8 : 11. 



In this specimen we have an ilhistration of the constancy of the 

 distinctive characters — namely, a broad crown and the height of the 

 enamel ridges, not much exceeding the width, being nearly in the 

 ratio of 11 : 8. 



Another detached penultimate upper molar, having the first five 

 ridges worn, shows ten and a talon. The digitations in this case 

 are so distinct that the disks of each of the first three ridges present 

 three subordinate disks. The dimensions of this specimen are — 



Inches, 



Length of crown 8-75 



Width of crown at first ridge 3-5 



Height of crown at sixth ridge, unworn 5-2 



This tooth exhibits all the distinctive characters noted of the other 

 teeth. The number of plates in the penultimate upper molar of 

 E. meridionalis, appears to range from nine to ten. 



Of the third or last upper true molar (sixth in theorder of succession) 

 there are numerous sjjecimens in the Plorentine Museum, some of 

 them in situ in entire crania, others detached. They are distinctly 

 shown in good preservation in three huge male skulls, with enor- 

 mous tusks, and in one female (?) head with smaller tusks ; but 

 in each of these cases the most anterior ridges are, from extreme 

 age, worn out ; and I prefer drawing an illustration from a perfect 

 detached specimen for the exact determination of the ridge-formula. 

 Among the most instructive of these are a pair belonging to op- 

 posite sides, and so much alike that they were probably of the same 

 individual. The molar of the right side (no. 9261 of the old Catal. 

 Florent. Mus.) shows thirteen ridges, besides talons. The disks of 

 the first two ridges and talon are nearly confluent into one common 

 "wide surface ; but the presence of the large anterior fang proves 

 that no part of the crown is lost in front. The eight succeeding 

 ridges are more or less abraded, the three last being intact. In ' 

 consequence of the plane of advanced wear intercepting the ridges 

 obliquely, the enamel plates appear to slope a great deal where 

 they emerge from the cement, and the edges project much above it. 

 The ninth ridge, which is but slightly abraded, exhibits eight or 

 nine distinct thick digitations. The crown contracts a good deal 

 towards the hind talon, which is enveloped by a thick mass of 

 cement. The principal dimensions are — Inches 



Extreme length of crown about 11-0 



Width of crown at the fourth ridge 4-3 



Width of ditto at base of ninth ridge 4-0 



Height of enamel plate at tenth ridge 4*5 



In this specimen, all the characters noticed as distinctive of the 

 anterior true molars ' are strongly marked. There are thirteen 



