ELEPHANT AND MASTODON. 



67 



guishing marks of species than of genera, in the gigantic 

 proboscidean family of mammalian quadrupeds. 



' Two dental characters, however, exist, though hitherto, I 

 believe, unnoticed as such,^ which distingviish, in a well- 

 marked and unequivocal manner, the genus Mastodon from 

 the genus Elephas. The first is the presence of two tusks 

 in the lower jaw of both sexes of the Mastodon, one or both 

 of which are retained in the male, and acquire a sufficiently 

 conspicuous size, although small in proportion to the upper 

 tusks, while both are early shed in the female. The second 

 character is equally decisive ; it is the displacement of the 

 first and second molars in the vertical direction, by a tooth 

 of a simpler form than the second, a true dent de remplace- 

 ment, developed above the deciduous teeth in the upper, 

 and below them in the under jaw. 



before the publication of part vi. of the 

 'British Fossil Mammalia.' Bronn's 

 elaborate definition of the genus Masto- 

 don begins with these words: — 'The 

 genus Mastodon (of which entire skele- 

 tons possessing even, as it seems, the 

 hyoid bone and stomach, have been found 

 in North America) exhibits in the skull, 

 in the tusks, in the numljer of toes, and 

 in all the characters of the skeleton 

 which admit of an inference as to the 

 nature of the soft parts, no other generic 

 difference from Elc2)has, excepting the 

 sufficiently important ones in the grinders 

 and lower incisors. The dental formula 

 3 > 



' Manuscript Note by Br. Falconer. — 

 Professor Owen has preferred a claim 

 to having first pointed out the infe- 

 rior tusks and the vertical premolar as 

 distinctive generic characters between 

 Mastodon and Elephas. His words are : 

 ' I first pointed out the inferior tusks, 

 whether transitory or persistent, as a 

 well-marked generic character of Masto- 

 don as contra-distinguished from Elephas 

 in my "History of British Fossil Mam- 

 malia" (p. 275); and also defined a 

 second character, in the displacement of 

 the first and second molars in the ver- 

 tical direction by a tooth of simpler form 

 than the second — a true "dent de rem- 

 placement," developed above the deci- 

 duous teeth in the upper and below them 

 in the under jaw. Both these dental 

 characters, which are of greater import- 

 ance than many accepted by modern 

 zoologists as sufficient demarcations of 

 existing generic groups of Mammalia, 

 have been recognized in the Mastodon 

 giganteus of North America arid in the 

 Mastodon angustidcns, which is the pre- 

 vailing species of Europe' (Odonto- 

 graphj'-, part iii. p. 615. June 18-16). 

 The passage above referred to in the 

 ' British Fossil Mammalia ' is thus : — 

 ' Two dental characters, however, exist, 

 though hitherto, I believe, unnoticed as 

 such, which distinguish in a well-marked 

 and unequivocal manner the genus Mas- 

 todon from the genus Elephas,' &c., as 

 in the Odontography (British Fos. 

 Mam. p. 274, part vi. 2 Dec. 1844). But 

 both of these characters are expressly 

 mentioned as generic points of distinc- 

 tion between Mastodon and Elephas by 

 Dr. Bronn, of Heidelberg, in his ' Le- 

 thsea,' as far back as 1838, six years 



is thus : -f ■ o" 



i. 



4 



The grinders 

 number : namely, 



' 3 

 appear in a larger 



there are present in both jaws from 1 to 

 4 of them contemporaneously, according 

 to species and age, which, as in the ele- 

 phant, are replaced two or three times ; 

 not, as usual, from below upwards (ver- 

 tically), but as in the latter, by teeth 

 which are pushed from back to front — 

 excepting, however, the most anterior of 

 these teeth ' ( Bronn, Lethaea Geog. 

 Band. ii. p. 1233). Then he defines 

 Elephas thus : — ' Essential character, 



"0 .' 0" •' 2" teeth ; viz. a huge tusk in 

 front, and compound grinders behind ; a 

 long muscular ti-unk ; five toes before 

 and behind' (p. 1239). In the continua- 

 tion, giving the general description, he 

 adds : — ' 'The elephant ordinarily has 

 only two grinders in each jaw at one 

 time (in advanced age only one, pro- 

 bably, as in mastodon), which are re- 

 placed by others, not, as usual, in a ver- 

 tical, but all in a horizontal direction • 

 and that not only once, but probably 

 three or four times,' &c. (p. 1240). In 



F2 



