CHART OF TYPOTHERIA 55 
AGE Formuta| CANINES | U. Mortars] Last 1.MoLar| Toes | 
Hegetotherium Santa Cruz | 3 1 4 3] vestigal | noinner 3-lobed cleft 
3143 : fold 
Prohegetotherium| Deseado no inner | 
fold 
Pachyrukhos Santa Cruz |_1 9 3 3] lacking | no inner 3-lobed not 
2033 fold cleft 
Propachyrucos Deseado _| slightly 3-lobed 
3143 reduced 
Prosotherium Deseado I 0 4 3) lacking | simple inner 3-lobed slightly|pm. simple 
2043 fold cleft 
Archaeophylus Deseado ? 1 43) rather deep inner 
large fold, slight 
outer one 
Interatherium Santa Cruz 3 143) vestigal |slight inner 2-lobed slightly 
3143 and outer cleft 
folds 
Protypotherium |SantaCruz | 3 1 4 3 large deep inner 2-lobed slightly closed series 
3143 and outer cleft 
folds i‘ 
Argyrohyrax Deseado 3143 large bifurcated 
inner fold 
Eutrachytherus Deseado 3 143) lacking |bifurcated 2-lobed 
2143 inner fold 
Isoproedrium Deseado 
iat 2s} 
Archaeohyrax Deseado 3143! large deep inner 3-lobed 
3143 fold, slight 
outer fold 
Plagiarthrus Deseado | 2-lobed 
Pras 
cially in the genera where the enamel is lacking on all but 
the front face, but this is entirely a parallelism and there 
is no evident phylogenetic relationship. As to affinities 
with the Hvyracoidea, Sinclair* has carefully balanced 
them and finds so little in common between the two groups 
*Princeton Expeditions Reports, Vol. VI, p. 7, 1909. 
