90 



and thus producing a high pre-narial rampart: incisors of lower jaw com- 

 paratively small and directed forwards, or entirely absent. Molars suc- 

 cessively displacing each other from behind forwards (and therefore no 

 pre-molars replacing the deciduous ones), and not more than two (or one) 

 fully developed at the same time. Skull abbreviated and enlarged 

 obliquely, convex backwards and outwards, and with the occipital con- 

 dyles declined. 



ELEPHANTIDAE. (LVIII.) 



II. Incisors of upper jaw atrophied or absent, (and consequently an uninter- 

 rupted oval depression occupying the naso-rnaxillary region) : incisors of 

 lower jaw (1-j-l) enlarged, and developed as tusks decurved downwards 

 and backwards, and involving the symphysial portion of the jaw. Molars 

 vertically developed (with pre-molars replacing the deciduous molars), 

 and in considerable number (PM f, M f X2) at the same time. Skull 

 moderately long, and with the occipital coudyles inclined upwards. 



DINOTHEBIIDAE. (LIX.) 

 LVIH. ELEPHANTIDAE. 



SUB-FAMILIES. 



I. Intermediate molars (D 4, M 1, 2) with an "isomerous" ridge formula 

 (t. e. with the ridges equal in number in the successive teeth three to 

 five): the ridges attypicaily continuous: the valleys with a thick deposit 

 of cementum. 



ELEPHANTINAE. (A.) 



II. Intermediate molars (D 4, M 1, 2) with a "hypisomerous" or "auiso- 

 merous" ridge formula (z. e. with the ridges increasing in number by one 

 ("hypisomerous") or more ("anisomerous") in the successive teeth (e.g. 

 D 4\ M I 8 , M 2 9 to D 4 12 P m -, M l^pm., M 2 18 P m -): the ridges with more or 

 less mammilliform tubercles: the valleys with little or no cementum. 



MASTODONTINAE. (B.) 

 A. ELEPHANTINAE. 



Elephas L'mnElasmodon "Fa\c.=Euelephas Falc. 

 Loxodonta F. Cuv.=Loxodon Falc. 



Extinct genus. 

 Stegodon Falc. 



B. MASTODONTINAE. 



Extinct. 



Pentalophodon Falc. 



Mastodon C\iv. = Tetrahj>hodon Falc. 



Tetracaulodon &odma.u=Trilophodon Falc. 



LIX. DlffOTHEKIIDAE. 



Extinct. 

 Dinotherium Kaup. 



