334 NOTES ON THE CANIDJE OF THE WHITE RIVER OLIGOCENE. 



The palatines are shaped very much as in Cam's. As a whole, the bony palate 

 differs from that of the latter genus in the greater and more abrupt expansion of its 

 posterior half, beginning at p ^ ; it is also somewhat more concave transversely and has 

 a more prominent ridge along the median line. The palatine foramina are likewise 

 somewhat different from those of recent dogs ; one conspicuous opening on each side 

 occupies the same position as in the latter, opposite the middle of the sectorial, but instead 

 of a single opening opposite m i, is a group of two or three minute foramina. 



The Cranial Foramina. Unfortunately, none of the specimens are sufficiently 

 well preserved to permit a complete account of the cranial foramina, though the more 

 important facts concerning these structures may be determined. Leidy states that in 

 D. vetus " the anterior condyloid, Eustachian and oval foramina present very nearly the 

 same condition as in the Wolf" ('69, p. 33). The specimen upon which Leidy's descrip- 

 tion was founded, belonging to the Academy of Natural Sciences of Philadelphia, has been 

 mislaid and is not at present available for comparison, but the description cited above 

 does not altogether apply to the cranium of D. hartshomianw, of which an account has 

 been given in the foregoing jmges. In this specimen the condylar foramen is widely 

 removed from the condyle, much more so than in Canis, and is placed near the edge of 

 the reniform fossa which lies behind the tympanic bulla. The existence of this fossa 

 removes the necessity for a distinct foramen lacerum posterius, which is indicated only 

 by a notch in the hinder margin of the fossa ; similarly, the stylomastoid foramen is an 

 open groove, only partially enclosed by bone. The postglenoid foramen is large and 

 conspicuous and is not concealed by the anterior lip of the auditory meatus as is the case 

 in the John Day Cynodesmus. The foramen lacerum medium appears to occupy a 

 somewhat more internal position than in Canis, though this is not altogether certain, 

 because of the unfavorable condition of the fossil just at this point. The Eustachian 

 canal is more concealed under the long anterior process given off' from the tympanic 

 bulla than in the existing genus, ami the foramen ovale is separated from the entrance to 

 the canal by a much more prominent bony ridge, so that the foramen presents forward 

 instead of downward. 



By a curious coincidence all the crania of Daphamus in the Princeton museum are 

 damaged in such a way that none of them displays the alisphenoid canal, the foramen 

 rotundum or the foramen lacerum anterius, though there is no reason to doubt that all of 

 these foramina were present and corresponded in position to those of Gams. The optic 

 foramen is overhung by a ridge, already described, which is much more prominent than 

 in the latter, ami the lachrymal foramen is decidedly larger and more conspicuous. The 

 parietal is perforated by a venous foramen which opens in the depression behind the 

 cerebral hemispheres ; this foramen, the postparietal, is not found in the modern genus. 



