438 Wortman — Studies of Eocene Mammalia in the 



canines. The nasals, of which the extreme anterior portions 

 are missing, are narrower in front than behind, as in the 

 carnivorous Marsupials, although the posterior widening is not 

 nearly so marked as in this group. They terminate posteri- 

 orly in a pointed extremity, which is situated near the center 

 of an unusually broad and deep frontal depression. The 

 nasals are not so wide posteriorly as to restrict the contact 

 between the frontals and maxillaries, as is the case in certain 

 of the carnivorous Marsupials, and in Dromocyon already 

 described, so that this feature of the skull is decidedly more 

 Carnassident in appearance. The maxillary is large and has a 

 form common to the carnivorous skull. The posterior subor- 

 bital region, however, is exceptionally broad, and is in every 

 way more extensive and primitive looking than in any of the 

 Carnassidents. Owing to the large facial development of the 

 lachrymal, the maxillary lacks considerable of reaching the 

 rim of the orbit. The infraorbital foramen is of goodly size, 

 and issues a short distance above the hinder edge of the third 

 premolar, about as in the fox. As already stated, the 

 lachrymal is relatively large and spread out upon the face, 

 having about the same pro]:>ortions and degree of facial 

 development as that of the opossum. It is perforated by a 

 distinct lachrymal canal, which lies wholly within the rim of 

 the orbit. The zygomatic arches are not preserved in either 

 specimen, but, if we are able to judge by their roots, they may 

 be said to have been intermediate in stoutness between those 

 of the dog and of the opossum. The anterior part of the 

 malar is preserved, and this, as is usually the case, furnishes 

 the lower anterior boundary of the orbit. In the Carnas- 

 sidentia, it joins the maxillary by means of a bifurcated 

 extremity. In the fossil, the lower ramus of this bifurcation 

 is very slightly developed — a condition which approximates 

 that of the opossum, in which it is entirely wanting. 



The frontals are rather broad anteriorly and terminate 

 opposite the infraorbital foramen, in triangular extremities 

 which do not meet the ascending processes of the prem axillae. 

 The position of the inconspicuous postorbital processes is 

 indicated by the termination of the strongly-marked, rapidly 

 diverging anterior branches of the sagittal crest, which furnish 

 the posterior boundary of the frontal depression. The sagittal 

 crest is not w^ell preserved, but enough is shown to indicate 

 that it had about the same relative degree of development as 

 that of Gymnura and the Dasyures. The form of the brain 

 case is much like that of certain of the civets, except that it 

 is longer, narrower, and of less capacity ; it is conical in front 

 with a slight median swelling, after which follows a relatively 

 long subcylindrical posterior portion. The parietals and 



