516 Reviews — Prof. Edward D. Cope — 



molars. The species are found in the John Day beds of Oregon. 

 Pleurolicus is another member of the same family. It is represented 

 by two species, and approximates to the existing genera Heteromys 

 and Perognathus, from the latter of which the most distinctive differ- 

 ence is the grooving of the upper incisors. 



The Lagomorpha is represented by three genera. Palceolagus is a 

 type which approximates towards Lepus, but it has no postfrontal 

 process, and the first inferior molar consists of one column, more or less 

 divided. A cast of the cerebral chamber shows that the olfactory 

 lobes are large, expanding abruptly from the hemispheres, from 

 which a constriction separates them. They are wider than long, and 

 wider than the front of the cerebrum. The brain was smaller than 

 in the Eabbit, and in the Palceolagus haydeni the cerebral hemispheres 

 are smaller, and the olfactory lobes larger. The number of teeth is 

 the same as in existing Babbits, but with age many changes appear, 

 which at first suggest the characters of different species. 



P. haydeni was widely distributed in Dakota, Colorado, and Oregon. 

 It is thought to have been the progenitor of Lepus sylvaticus, which 

 now inhabits North America. P. triplex was rather larger than the 

 prairie Marmot. Lepus emisianus is the only species of the genus 

 found in the John Day Eiver beds. It is distinguished by the free 

 short postorbital processes, which are narrower than in L. auduboni, 

 and behind these processes the cranium is narrower. The mandible 

 has the form of L. sylvaticus, which the animal resembled in size. 

 The remainder of the volume is devoted to the Carnivora. 



From the views already developed by the author, it is interesting 

 to find the Carnivora distinguished as clawed Mammalia with trans- 

 verse glenoid cavity of the squamosal bone, confluent scaphoid and 

 lunar bones of the carpus, and well-developed cerebral hemispheres. 

 A good deal is made of the cerebral hemispheres, because some 

 Insectivora possess a united scapholunar bone. Hence the crucial 

 fissure of the hemispheres, which is present in all Carnivora, except 

 one or two of the Melinge, becomes as important a characteristic as 

 the absence of the parieto-occipital, and calcarine fissm - es. The 

 author makes two primary divisions of the order : first, Hypomj'cteri, 

 in which the external nostril is occupied by the complex maxillo- 

 turbinal bone, while the ethmo-turbinal bones are confined to the 

 hinder part of the nasal fossa, and the inferior ethmo-turbinal is of 

 small size ; and, secondly, the Epimycteri, in which the external 

 nostril is occupied by the inferior ethmo-turbinal and the reduced 

 maxillo-turbinal. The Hypomycteri stand next to the Pinnipedia, 

 since the maxillo-turbinal bone has the same anterior development 

 in that group. The division of the groups into families depends 

 upon the presence of sectorial teeth, which are defined as having at 

 least two external tubercles, and by the flattening and emargination 

 of their continuous edges, the sectorial blade is formed. Other 

 characters are found in the number and form of the molars, the 

 presence or absence of an alisphenoid canal, the character of the otic 

 bulla and the number of toes. 



The Canidse were abundant in the Miocene of North America, but 



