1082 The Artiodactyla. 
character. In Elotherium traces of both the intermediates are 
visible, but they are obscure. The genetic relations of the families 
with five lobes to those with four are supposed by Schlosser to be 
direct and ancestral. This looks probable in the case of the Mery- 
copotamidæ of the latter group, which has inferior molars like those 
of Hyopotamus of the former group. Whether the remaining 
families of division III AA (see table) (four-lobed) came off from 
the families of division ITI (five-lobed) is uncertain. It is probable 
that the fifth and sixth (or intermediate) tubercles were present in 
all primitive Artiodactyla, but they may have been lost, as in the 
Suidæ, in the bunodont stage, which gave origin to III AA, so as 
to be wanting from the earliest four-lobed selenodont ancestors. 
Of the two types of II (Anthracotheroidea) the division Æ is supposed 
by Schlosser to have been the ancestor of the true selenodonts 
(III 44), but excepting in the case of Merycopotamide, this has 
not yet been demonstrated. Scott suspects with reason that the 
quinquetubercular Protoreodon is the ancestor of the quadrituber- 
cular Oreodon. 
Leaving this debatable question, I refer to the family of the 
Anoplotheriide. The remarkable structure of the feet discovered 
by Gervais, and shown by Schlosser to belong 
to this family distinguishes it at once from 
all families of this and all other orders. | 
ul The second digit is well developed in both 
| i feet, and stands inwards at a strong angle to 
` the other toes. A rudimental fifth is present 
ji in the manus, but not in the pes. The latter 
i * is therefore tridactyle. The third and fourth 
i digits are equal in the pes, but the third er” 
a U ceeds the fourth in the manus, giving an entirely 
SG perissodactyle character. Some didactyle forme 
» aig de Bight poste- have been placed in this family, but this is m- 
ium latipes Ger tnat. admissible on ordinary taxonomic principles. 
a ., Calcaneum ; ý A ° 
SUTTY astragalus; Cub., The divergent Inner toe is sup to have 
cuboid ; . cunei 7 io lif AS 
szprom the Eo- supported a web, useful in an aquatic tite. 
Gaudry, Enab einan $ he origin of the Anop- 
du Monde Animar remarked by Schlosser, the orig H 
lotheride is entirely obscure as yet, the only ancestor yet kno a 
being the Pantolestida. It is probable that some unknow 
member of the Anthracotheroidea, which had bunodont teeth, may 
