No. 5.] PARIOriCHUS INCISIVUS COPE. 235 



An analytical tabic gives the characters of the various 

 species (p. 445): 



I. The long maxillary tooth below the anterior border of 

 the orbit. 

 Head short, wide ; orbits small, half interorbital 



width; length of skull about 25 mm P.brachyops. 



II. The long maxillary tooth nearer the nostril than the 

 orbit. 

 a. Sculpture reticulate. 



Interorbital and parietal sculpture reticulate ; inter- 

 orbital width 20 mm.; interior jaw teeth with round 



crowns P. incisivzis. 



aa. Sculpture more or less in longitudinal ridges. 



Interorbital sculpture in longitudinal ridges; inter- 

 orbital width 9 mm., equal orbit ; maxillary tusk 

 abruptly longer P. ordinatus. 



Cranial sculpture in longitudinal ridges ; orbit about 

 equal interorbital width ; skull equilateral, straight 

 posteriorly; length 72 mm.; inner jaw teeth com- 

 pressed P. isolomiis. 



Cranial sculpture partly reticulate, especially medially ; 

 orbit about equal interorbital width ; width of skull 

 three-quarters length ; outline emarginate posteri- 

 orly, length 80 mm P. aguti. 



Orbit oval; cranium 162 mm. long, and nearly as 

 wide ; posterior border emarginate ; muzzle much 

 contracted, entirely overhanging symphysis man- 

 dibuli P- haniatus. 



To these was added P. aduncns in a later article (6), charac- 

 terized by the strong decurvature of the anterior end of the 

 muzzle and the gradation in the size of the maxillary teeth 

 instead of the single abruptly large one. 



As the specimen here described has been identified as 

 P. incisivHS, it is necessary to give the generic and specific 

 characters of Ectocynodon incishms, under which name it was 

 oiiginally described. The generic description was given in 

 1878 (i) (p. 508): "Cranium short and wide, with large post- 

 frontal bones and a large orbit. Cranial bones sculptured, but 

 no lyra. Teeth rhizodont with elongate compressed crowns 

 with anterior and posterior cutting edges. One of these 



