PLEISTOCENE VERTEBRATES EROM CUMBERLAND CAVE 13 



nearest living forms. The most important of these are concerned 

 with the less inflated condition of the brain case and appear not to be 

 due to crushing. The frontal region in C. alleganiensis does not pro- 

 ject so markedly above the doreal plane of the rostrum; consequently 

 the dorsal profile from the nasal opening to the top of the frontals 

 more nearly approaches a straight line. Also, the median pit or 

 depression in the dorsal surface of the rostrum is not so deep as in 

 C. rqfinesquii and is not separated from the anterior nasal notch by 

 so conspicuous a ridge. The height of the posterior portion of the 

 cranium as measured from the occipital condyles to the top of the 

 interparietal is noticeably less in the fossil. Furthermore, the con- 

 dyles are slightly farther forward in position as indicated by the dis- 

 tance between the preserved condyle on the left side and the glenoid 

 fossa. This suggests that the bullae, though not preserved in the 

 fossil, may have been of smaller anteroposterior diameter or possibly 

 not so well separated from the condyles. The temporal ridges at the 

 anterodorsal margins of the temporal fossae are distinct and converge 

 backward but instead of uniting to form a sagittal crest continue 

 posteriori}^ a short distance as nearly parallel ridges. This character 

 was also clearly observed in a second, more incomplete skull portion of 

 C. alleganiensis (no. 12415). In all specimens of C. macrotis and C. 

 rqfinesquii examined these lateral ridges unite posteriorly to form a 

 short median ridge. Furthermore, these ridges in C. alleganiensis 

 are somewhat better defined anteriorly than in modern forms and at 

 the termination of each is the very slightest suggestion of a postorbital 

 process. 



Corynorhinus phyllotis Allen (1916, pp. 352-353) from the region of 

 San Luis Potosi in Mexico, though defined as having a flattened 

 brain case, is apparently a larger and broader-skulled type than 

 C. alleganiensis. The rostrum of C. phyllotis is described as more 

 depressed and having a more marked median excavation than other 

 living species of Corynorhinus. Furthermore, the audital bullae are 

 even larger than in the more northern species. 



No important or consistent differences were observed between the 

 dentition of C. alleganiensis and that of the living forms of Coryno- 

 rhinus. Also, the lower jaws are apparently not distinguishable from 

 those of modern forms. Although the dental formula for the lower 

 jaw of Corynorhinus is the same as in Myotis, not one of the many 

 specimens from Cumberland Cave was found to represent the latter 

 genus. It is probable that Gidley had reference to this Corynorhinus 

 lower jaw material when he included Myotis in his faunal list of 1913. 

 The mandible of Corynorhinus has a relatively shorter premolar series 

 and longer molar series than does that of Myotis. 



The presence of Corynorhinus in the fauna is of particular interest 

 inasmuch as it is the first record of the genus from the Pleistocene and 



