60 



BULLETIN 171, UNITED STATES NATIONAL MUSEUM 



magister. The specimens compare favorably in size with the cotype 

 material from Carlisle Cave, Pa., being somewhat larger and deeper 

 jawed than in an average living specimen of A^. pennsylvanica}* The 

 Cumberland Cave specimens are characterized by a relatively long 

 mandibular symphysis, robust incisors, and cheek teeth with postero- 

 external reentrant folds widely U-shaped and deeply pocketed at base. 



Figure Z2.—Neotoma magister Baird: Left ramus of mandible (U.S.N.M. no. 12033), lateral and occlusal 

 views. X2. Cumberland Cave Pleistocene, Maryland. 



The Cumberland form is readily distinguished from N. jloridana by 

 its greater size, larger incisors, and relatively longer diastema between 

 incisor and cheek teeth. 



N. ozarkensis Brown (190S, pp. 196-197) is apparently somewhat 

 smaller than the Cumberland Cave wood rat, presumably nearer in 

 size to A^. pennsylvanica. 



Table 18. — Measurements (in millimeters) of mandible and inferior dentition of 



Neotoma magister 



Measurement 



Lencth of lower molar series measured at occlusal surface 



Length of lower molar series measured along alveoli 



Ml, anteroposterior length 



Ml, transverse width 



M}, anteroposterior length 



Mj, transverse width 



Mj, anteroposterior length 



Mj, transverse width.. 



Depth of ramus at junction of Mj and Mi 



U.S.N.M. 

 no. 12033 



9.7 

 3.4 

 1.9 

 2.8 

 2.2 

 2.2 

 L9 

 6.6 



U.S.N.M. 

 no. 12034 



9.4 

 10 

 3.7 

 2.1 

 3 



2.2 

 2.3 

 L0 

 6.8 



PARAHODOMYS SPELAEUS Gidley and Gazin '• 



Figures 33, 34 



Type. — Portion of the right ramus of a mandible (young individual), 

 U.S.N.M. no. 12040 (fig. 33), with all cheek teeth and part of alveolus 

 for incisor. 



Generic characters. — Cheek teeth in general structure as in Hodomys, 

 but with reentrant valleys, especially the external ones, shallower and 



n The possibility of N. pennsytvanica Stone being a synonym of N. magister Baird was noted by Rhoads, 

 1894, pp. 213-221. 

 i« Qidley and Gazin, 1933, pp. 350-357, figs. 8, 9. 



