The Artiodactyla. 1095 
of the family of the Nimravide. The large Merycocheeri possessed 
the means of making a formidable defense, but the Merychyi of 
later age were of decidedly less vigorous mould (Plate XXVII). 
The species of Leptauchenia and Cyclopidius were probably aquatic 
in their habits. The species of the last named genus (Plate 
XXVIII.) had produced tympanic bones like the hippopotamus for 
the insertion of ears that projected above the water, while the eyes 
are partly vertical to permit of vision without much exposure of 
the head. The nostrils are at the extremity of a sharp muzzle like 
the snapping tortoise to premit of breathing without exposure 
of the face. The object of the remarkable facial vacuities in 
this genus and Leptauchenia is unknown. It may have per- 
mitted the attachment of an inflatable integument like the nasal 
hood of the hooded seal. In Pithecistes the incisor teeth have 
disappeared, and the short deep jaw, the only part which is 
known, resembles in its codssified symphysis, that of a monkey. 
(To be continued. ): 
