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-maxillary region) : incisors of 

 lower jaw (1+1) enlarged, and developed as tusks decurved downwards 

 and backwards, and involving the symphysial poition 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 condyles inclined upwards. 



DINOTHEEIIDAE. (LIX.) 



LVIH. ELEPHANTIDAE. 



SUB-FAMILIES. 



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

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

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

 of cemeutum. 



ELEPHANTINAI. (A.) 



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

 merous" ridge formula (i. 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 to D 4 U P-, M 1"P-, M 2 18 P m -): the ridges with more or 

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



MASTODONTINAB. ( B.) 

 A. ELEPHANTINAE. 



ElepJias Linn=Elasmodon Fa,lc.=Euelephas Falc. 

 Loxodonta F. C\iv.=Loxodon Falc. 



Extinct genus. 

 Stegodon Falo. 



B. MASTODONTIWAE. 



Extinct. 



Pentalophodon Falc. 

 Mastodon Cuv.=Tetralophodon Falc. 

 Tetracaulodon Grodma,n=Trilophodon Falc. 



LIZ. DINOTHERIIDAE. 



Extinct. 

 Dinotherium Kaup. 



