116 Annals of the Carnegie Museum. 



On further comparison of the dentitions of Platigonns and Mylohyus, 

 there is little or no doubt about the close relationship so far as the 

 incisors and canines are concerned. But in comparing the cheek-teeth 

 (especially the lower), on the other hand, one is practically forced to the 

 conclusion that there must have been a form with crowns lower and 

 more bunodont than obtain in, for instance, P. leptorhinus, to give rise 

 to the condition found in Mylohyiis. Whether such forms may al- 

 ready have been described, e. g., in the case of P. vetus Le dy, can only 

 be determined by making a thorough review of all types and all other 

 available material. 



The skeleton, as it now appears in PI. XXIX, has been finely 

 mounted by Mr. Serafino Agostini under the direction of the writer. 

 As may be observed in the photographic reproduction, the upright 

 supports are eliminated by passing small steel rods through the limb- 

 bones; which rods pass back of each foot to the base, thus supporting 

 not only the limbs but the axial skeleton as well. Although the mate- 

 rial represents different individuals, each component part is thought 

 to be in approximately its proper position and the skeleton is thought 

 to fairly well represent the bony structure, possibly of a female. 



The vertebral formula is probably as follows: Cervicals 7; dorsals 

 14; lumbars 6; sacrals 4-5; caudals 8 + ?• The cervical region is 

 rather heavy; the third, fourth, and fifth cervicals are without distinct 

 spinous processes. The dorso-lumbar series are provided with promi- 

 nent neural spines, the dorsals back of the tenth assuming a lumbar- 

 like shape. The transverse processes of the lumbars are not heavy, 

 but of considerable lateral extent, while the sacrum is apparently 

 narrow and long. The ribs, though narrow, are quite flat throughout, 

 and thus closely approximate those of recent forms. There are present 

 in the skeleton five sternebrse which are rather heavy, the posterior 

 ones broad as in the recent peccaries. There are also present a number 

 of sternal ribs. 



The limbs, and especially the feet, are as characteristic as is the 

 head of this genus. The remarkable reduction of the lateral digits of 

 Platigonus over those of the recent forms is especially worthy of note 

 and is well described and illustrated bv Professor Williston and others. 



