36 NORTH AMERICAN FAUNA. [No. 40. . 



A verages of adult male specimens of Cynomys. 



Species and locality. 



Number of speci- 

 mens averaged. 



Skin. 



Skull. 



Total length. 



Tail vertebrae. 



Hind foot. 



Condylobasal 

 length. 



Zygomatic 

 breadth. 



Mastoid 

 breadth. 



Nasals. 



Mandible. 



Maxillary 

 tooth row. ' 



G. tUCLOVtCtClTlUS lUdOVlClCLTlltS , 























Montana 



6 



383 



84 



61 



60. 4 



45. 1 



28. 0 



22. 8 



45. 8 



16. 4 



North. Dakota 





405 



96 



64 



61. 4 



45. 5 



28. 1 



23. 1 



45. 9 



16. 9 



South Dakota 



13 



388 



86 



62 



59! 8 



45! 0 



28^5 



23! 8 



45^9 



16.' 6 



Wyoming 



4 



393 



86 



63 



60.7 



45.3 



28.3 



24.0 



46.2 



16.8 



Nebraska 



3 



397 



86 



62 



60.9 



45.8 



28.9 



23.4 



46.3 



16.8 





4 



364 



82 



62 



58.9 



44.1 



27.8 



23.1 



45.1 



16.9 





10 



380 



88 



62 



59. 7 



44. 7 



27, 8 



23. 1 



45. 5 



16. 5 



Oklahoma 



2 



376 



110 



63 



60!6 



44! 5 



28^3 



23! 5 



46^6 



17.' 2 



Texas 



7 



392 



88 



62 



61. 5 



45. 5 



29. 0 



24. 5 



46. 9 



16. 7 



C. ludovicianus arizonensis. 























Texas — 



7 



395 



88 



64 



60.3 



44.7 



27.7 



24.3 



46.5 



16.6 





18 



381 



84 



62 



60. 1 



44. 3 



28 0 



23. 8 



45. 0 



16. 2 





19 



388 



89 



62 



60.' 0 



44! 0 



27^3 



24! 0 



45! 2 



16^2 



Chihuahua 



1 



400 



80 



65 



62.9 



45.0 



29.1 



23.5 



46.0 



16.6 



C. mexicanus. 























Coahuila 



8 



416 



102 



63 



59.3 



44.6 



28.6 



23.0 



43.8 



15.9 



C. leucurus. 























Wyoming 



13 



358 



57 



62 



58.7 



43.8 



29.0 



22.0 



43.1 



15.7 





6 



368 



56 



63 



60.0 



44.6 



29.8 



22.6 



45.0 



15.6 



C. parvidens. 























Utah 



8 



338 



43 



59 



55.9 



42.2 



28.6 



21.8 



42.3 



15.0 



C. gunnisoni gunnisoni. 























Colorado 



12 



340 



53 



56 



54.8 



42.5 



27.0 



23.5 



41.9 



14.5 



New Mexico 



1 



328 



68 



54 



53.4 



41.3 



25.8 



21.5 



40.0 



14.8 



C. gunnisoni zuniensis. 

























17 



344 



60 



58 



55.0 



41.9 



27.4 



21.5 



42.3 



14.8 





9 



355 



62 



60 



55.8 



43.5 



27.4 



21.9 



42.7 



14.5 



Plate I. 

 (About natural size.) 



Figs, land 4. Cynomys ludovwimms ludovicianus (Ord). c? ad. Glendive, Montana. 



(No. 191411, U. S. Nat. Mus.) 

 Figs. 2 and 5. Cynomys ludovicianus arizonensis Mearns. ad. San Pedro River, 



Arizona. (No. 35873, U. S. Nat. Mus.) 

 Fig. 3. Cynomys mexicanus Merriam. J" ad. La Ventura, Coahuila, Mexico. (No. 



79550, U. S. Nat. Mus., Biological Survey collection.) 



