604 THE PUEECO FAUNA. 



verse, .0085. Width of first true molar in front, .0083. Apparently abo'it 

 the size of a sheejD. 



The second and more perfect specimen of this species includes a con- 

 siderable part of the skull, with maxillary bone and teeth, the latter bone 

 not continuous with the others. There are thirteen vertebrae from all parts 

 of the column; more or less of two humeri, neither with the head, both 

 ilia; the proximal part of the femur; the astragalus, navicular, and several 

 metatarsals and phalanges. 



The posterior part of the skull is very opossum-like. It is long and 

 narrow, and the sagittal and lateral occipital crests are much produced. 

 Above the foramen magnum the occipital bone is deeply concave. The 

 lateral occipital crest divides at its inferior portion into two ridges, which 

 run nearly parallel and inclose between them a shallow lenticular fossa. 

 The posterior ridge terminates in a short oval tuberosity, the paramastoid 

 jDrocess, which bounds the auricular meatus posteriorly. The anterior 

 terminates higher up, at the superior anterior angle of the tuberosity, with- 

 out expansion, on a level with the superior edge of the meatus, thus not 

 producing a post-tympanic process. The internal extremity of the post- 

 glenoid process is produced into a narrow ridge which extends inwards and 

 then forwards, bounding an oval fossa arranged anteroposteriorly. Its 

 internal border is indicated by a narrow tuberosity, between which and the 

 ridge before mentioned is a longitudinal groove. The anterior temporal 

 ridge is an obtuse angle continuing the half of the sagittal crest to the 

 postorbital angle. The muzzle is naiTowed upwards, and the nasal bones, 

 though not narrowed, are together, obtusely roof-shaped. The facial por- 

 tion of the premaxillary bone is remarkably wide anteroposteriorly, the 

 width nearly equaling the depth in front of the canine tooth. The malar 

 bone is very prominent, extending laterally much beyond the maxillary 

 above the molar teeth. It presents no postorbital angle, but has on its ex- 

 ternal face a wide groove. This is overhung by a strong ridge anteriorly, 

 which descends anteriorly and ceases above the anterior part of the second 

 true molar. The groove runs out below, and becomes distally two planes, 

 a lateral and an inferior separated by a prominent angle. The zygomatic 

 fossa terminates anteriorly in a sinus which is opposite to the anterior edge 



