1888. ] 67 
[Cope. 
BoOTHROLABIS SUB4QUANS Cope. 
Palwocherus subequans Cope. Proceeds. Amer. Philos. Soc. 1879, p. 
374. 
This species is only known to me from a single nearly entire skull with 
lower jaw in the collection of Prof. Thomas Condon, of the University of 
Oregon. The specimen he kindly lent to me, and my description and 
figures are based upon it. It is distinguished among those of its con- 
geners by its abbreviated and robust form. This is seen in the steepness 
of its profile, the concavity of the side of the muzzle, and in certain 
details. Such are the position of the superior p. m. iv within the superior 
canine ; the absence of diastemata between the premolars, and the short- 
ness of the last true superior molar. 
The frontal region is swollen above the anterior parts of the orbits, but 
is concave in front of the temporal ridges, except at the median line, 
which is obtusely keeled at this point. The profile does not descend ab- 
ruptly as in the Chaenohyus decedens, but forms a steeply descending 
straight line. In the same way the face is not abruptly contracted at the 
front of the malar bones, but slopes rapidly inwards, giving a wedge- 
shaped outline from above. Anterior to the compression the facial sur- 
face expands laterally and encloses the canine alveoli without abrupt 
enlargement. Anterior to these teeth the fossm for the inferior canine are 
excavated upwards and backwards to a depth of about one-fourth the 
vertical diameter of the muzzle, the molar teeth being held horizontally. 
The greater part of the premaxillary bones are broken off. The orbit is 
not large. The postorbital process is large and decurved, with its com- 
pressed-acute apex pointing downwards, behind the line of the postorbital 
process of the molar. The anterior border of the orbit has two notches, 
the inferior the larger and including the lachrymal foramen. The supra- 
orbital border is nearly straight. The temporal ridges are sharply defined. 
The sagittal crest is compressed and deep through the posterior depression 
of the brain case, as it does not quite rise to the plane of the facial pro- 
file. The occiput is narrow and elevated, and its lateral crests are promi- 
nent, enclosing a spoon-shaped occipital fossa. The inion is a narrow 
truncate angle less than right. The occipital condyle projects at its 
superior part, exterior to the vertical line of the lateral occipital crest. 
The crest extends directly towards it without reaching it, and does not 
turn anteriorly to bound the temporal fossa below as in most Mammalia, 
including the peccary. It follows that the paroccipital and zygomatic 
crests originate independently. The latter is prominent, rising abruptly 
above and sloping backwards and inwards to a prominent apex nearer to 
the occipital condyle than to the postglenoid process. It has a deep trans- 
verse groove on its external face. The posttympanic region is a flat bone 
Spread out against the posterior aspect of the zygoma as in pigs generally. 
Its flat posterior plane is nearly vertical. Below its inferior border projects 
the postglenoid process, which is narrow, thinning out and becoming more 
