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. 
lg tail 
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 portion of the jaw. Molars 
vertically developed (with pre-molars replacing the deciduous molars), 
and in considerable number (PM 2, M 3x2) at the same time. Skull 
moderately long, and with the occipital condyles inclined upwards. 
DINOTHERIIDAE, (LIX.) 
LVIII, ELEPHANTIDAE. 
SUB-FAMILIES. 
I. Intermediate molars (D 4, M 1, 2) with an “‘isomerous” ridge formula 
(2. 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 cementum. 
ELEPHANTINAE. 
Il. Intermediate molars (D 4, M 1, 2) with a “hypisomerous” or “aniso- 
merous” ridge formula (2. e. with the ridges increasing in number by one 
(‘‘hypisomerous”) or more (“anisomerous’’) in the successive teeth (e. g. 
D 47, M 18, M 2° to D 42pm. M 116pm., M 218pm.): the ridges with more or 
less mammilliform tubercles: the valleys with little or no cementum. 
MASTODONTINAE, 
A, ELEPHANTINAE; 
Elephas Linn=Elasmodon Falc.=Luelephas Fale. 
Loxodonta F, Cuv.=Lozxodon Fale. 
Extinet genus. 
Stegodon Fale. 
B. MASTODONTINAE, 
Extinct. 
Pentalophodon Fale. 
Mastodon Cuy.=Tetralophodon Falc. 
Tetracaulodon Godman=Trilophodon Fale. 
LIX. DINOTHERIIDAE. 
Extinct, 
Dinotherium Kaup. 
(A.) 
(B,) 
