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and 
_ tirely distinct (Figs. 3,7). The molar a aug tre rs 
1886.] The Phylogeny of the Camelide. 613 
The only genera which include existing species are Camelus 
and Auchenia, the camels and llamas p D Mi 
respectively, It may be remarked that 
the latter genus, which is confined to the 
new world, is more specialized than 
Camelus, which is restricted to the old 
world 
Ancestral to the Camelidæ is the 
genus Protolabis Cope (Fig. 10), which 
agrees with Procamelus (Fig. 11), the 
earliest genus of that family in most 
respects, but differs decidedly in having 
a full set of superior incisor teeth. In 
this genus we reach the stage, in tracing 
back the ancestry of the camels, which 
We find represented by Oreodon in the 
series of the Chevrotains (Tragulidz), or 
the Gelocus in the line of the cattle and 
deer. It is probable, though not certain, 
that in Protolabis the metapodial bones 
are combined into a cannon bone as in 
the Camelide. If so it differs mate. 
nally from its predecessor, the genus 
Poëbrotherium, and must be regarded as 
the type of a special family, the Proto- 
labididze, : 
The Poébrotheriidze have their general 
characters like those of the Protolabi- 
didæ, but th R IG, 2. — Carpus 
®, but the metapodial bones are en- bone first 
from New 
teeth are truly selenodont, and the cres- vidual Fig. 12; a, pag b, 
c i d, i erior views. riginal, 
ents, as in the other families, are but 8 Rept. U. S. G. G. Tork 
rooth mer., G. 
four in number. The premolars are en- W. of 
tirel diff 3 Wheeler. 
Y erent in form from the molars 
baa the last one in the upper jaw consists of but two crescents, as 
in ruminants generally. ; ee 
The family which should be ancestral to the Poëbrotheriidæ is 
not certainly known. It should possess the foot-characters of the 
: (Pines a ıl r inf >. é A Superior, molars That ia 3 
er With Anad 
f 
be 
. 
