322 SYNOPSIS OF THE VERTEBRATE PAUNA OF THE PUERCO SERIES. 



The condyle is broken off, but it was probably elevated a little above the line of the 

 molars. Masseteric fossa well defined anteriorly, but not inferiorly. The angular 

 region is perfectly flat and straight. The dental foramen is below the middle of the 

 coronoid process, and just below the line of the bases of the crow^ns of the molars. 

 Mental foramina two, in horizontal line. 



The inferior canine was large and compi-essed; part of its alveolus only remains. 

 The molars and premolars are small. The crowns of the fourth and thii'd premolars 

 are lost, but judging from the extent covered by the two roots of the third, it is as large 

 as or a little larger than the second. The second has a simple slightly compressed 

 conical crown, with a small posterior transverse heel. The first premolai* is a large 

 tooth, and judging from the alveoli, of greater anteroposterior extent than any of the 

 true molars. The true molars are somewhat worn with use. The anterior part of the 

 crown is more elevated than the posterior, offering in this a resemblance to the M. 

 conidens, and a contrast to the M. corrugatus and M.ferox. The fifth cusp is en- 

 tirely on the inner side of the crown, and is close to the fourth, which it did not equal 

 in elevation when unworn. The heel of the third molar is short so that the length of 

 the crown does not exceed that of the second true molar, which is the most robust of 

 the series. There is a cingulum on the external base of the true molars, and another 

 on the internal base of the anterior half of the crown of the same. The enamel is 

 minutely rugose. 



Measurements. M. 



Estimated length of ramus to below condyle 185 



Depth at m. i 044 



" m. iii 040 



Width at base of coronoid in front 015 



Length of molar series 081 



" " true molars 037 



Diameter of canine alveolus (greatest) 020 



^. , , f anteroposterior 0145 



Diameters base of p, m. i .^ 



I transverse 009 



f anteroposterior Oil 



Diameters m. i \ 



transverse 0095 



{anteroposterior, 

 transverse 



, ,,„„_ 0125 



Diameters m. u { 



010 



^. , ... f anteroposterior 0125 



Diameters m. lu ^ ' 



( transverse 0095 



From the lowest bed of the Puerco of ISTew Mexico. D. Baldwin. 



If the skull of this animal was proportioned as in allied forms it was about the 

 size of that of the black bear ( Ursus americanus). 



