38 GEOLOGICAL SURVF.Y OF TEXASl 



pared it. The vertical diameter of tlie orbit outers the postorbital length 

 3.5 times. In the P. gracilis it enters 2.5 times, and in the P. angusti- 

 dens twice. The frontal width enters the same 1.25 times. In P. gracilis 

 it enters .75 times, and in P. angustidens .66 times. The parietal profile 

 is decurved posteriori}'-, as in P. gracilis^ and the inion is a prominent 

 convex crest. The sagital crest is elongate in correspondence with the 

 elongate parietal region. There is no evidence of the deep superciliary 

 notcli which is so striking in tlie two species of the genus above named. 

 The paroccipital and postgienoid processes are elongate, the former a Uttle 

 the shorter, and fused with it for more than half the length of the latter. 

 The latter dimension from the auricular meatus equals the vertical diam- 

 eter of the orbit, as in P. gracilis. The maxillary bone projects posterior 

 to the last molar 10 mm., or opposite to the anterior border of the pos- 

 terior nares. The lateral palatine notches extend 13 mm. anterior to the 

 l^osterior extremit}'^ of the maxillary bone. 



The mandibular ramus is remarkable for its slender proportions. Its 

 posterior border has a well defined offset near the extremity of the post- 

 gienoid process when in place. The coronoid process is greatly elevated, 

 reaching when in place to a point above the frontal plane. 



The crowns of the second and third true molars in both jaws (the only 

 ones preserved), are compressed. Vertical ridges are little marked on 

 the internal side of the crowns of the inferior molars. The third lobe of 

 the last inferior molar is narrow, and only half as long anteroposteriorly 

 as each of the other columns. 



Measurements. 



Mm. 



Length of fragment 200 



Length from anterior border of zygomatic foramen to inion (axial) 128 



Length from foramen magnum to palatal border 98 



Interorbital width 140 



Width at auricular meatus (compressed ? ) 58 



Width of occipital condyles 45 



Width of palate at front of last molar 27 



Width of posterior nares 12.5 



Elevation of lower jaw at coronoid .* 142 



Elevation of lower jaw at M. ii 23 



Width of lower jaw at condyle 43 



Width of lower jaw at angle ... 67 



( anteroposterior 24 



Diameters superior M. ii | transverse at base 18 



( anteroposterior 25 



Diameters superior M. iii -j transverse at base 18 



( anteroposterior 23 



Diameters inferior M. ii j transverse at base 12 



( anteroposterior 30 



Diameters inferior M. iii | transverse at base 14 



