FALCO]!^EE MASTOBO^r AXD ELEPHANT. 315 



ridges, however compressed, are wedge-shaped bodies, the disks of 

 wear not only necessarily become wider as they get lower, but, from 

 the obliquity of the plane that intercepts the ridges, they expose, in 

 old teeth that are used down to the base, a broader surface than the 

 actual width of the ridges, measured in a straight line. From not 

 paying due regard to the cause, observers have been led to regard 

 what is in reality only an accident of advanced wear in such cases 

 as indicating "thick-plated" varieties, and as subversive of the 

 specific distinction between the Mammoth and E. mericl'ionalis. 



2. Indian Elephant. — The leading features of the dentition of 

 this species are so well known from the excellent descriptions and 

 figures of Corse, followed up by Cuvier, De Blainville, and other 

 comparative anatomists, and the materials are so abundant in Euro- 

 pean collections, that I shall confine my remarks, on the present 

 occasion, chieflj^ to the points which aff'ect the determination of the 

 ridge-formula in the successive teeth. But it is necessary to enter 

 with some detail of evidence upon this part of the subject, as the 

 results to which I have been led diff'er in some important respects 

 from those arrived at by previous observers, on what concerns the 

 ridge-characters of the intermediate molars. 



a. Milk-molars. — The antepenultimate andpenultimate milk-molars 

 (d. m. 2 and d. m. 3) are seen in situ in the upper jaw of the young- 

 cranium figured by Corse, which is now preserved in the Museum of 

 the India House. The antepenultimate presents four ridges, and 

 measures but 7 inches in length. This tooth is exceedingly rudimen- 

 tary in form and dimensions. The penultimate is composed of eight 

 principal ridges, with an anterior talon-ridgelet, but no posterior 

 talon. The eighth or last ridge is as well developed as the others, 

 showing eight distinct digital processes. The dimensions of this 

 specimen are — length 2-4 inches, width in front -9 inch, width be- 

 hind l"3inch. The alveolus of the last mUk-molar, separated from 

 the penultimate by a partition, is present in this specimen, but 

 empty. 



The lower jaw of the same cranium furnishes the three milk- 

 molars in place. The antepenultimate, like the corresponding upper 

 tooth, is composed of four ridges, and measures "65 inch long. The 

 penultimate has eight principal ridges, with a small posterior talon. 

 It is longer and narrower in proportion than the ii2:)per ; it measures 

 2'55 inches in length. Eleven germs of the ridges of the last milk- 

 molar are lying loose in the alveolus or cavity of that tooth. 



A young cranium belonging to a skeleton in the Museum of King's 

 College, London, and having the lower jaw attached, furnishes the 

 next stage of dentition — namely, the penultimate and last milk-molars, 

 in situ. The penultimate is much worn, the two front ridges being 

 ground down to the base. The cro\vn presents eight principal ridges, 

 with indications of an anterior talon. The disks of wear are wide, 

 and the enamel-border well crimped, but with no tendency to mesial^ 

 expansion. The dimensions are — length 2-7 inches, width of crown 

 in front 1-2 inch, behind 1-5 inch. 



The last or third milk molar, left side, has a crown composed of 



