PEOCEEDINGS OF UNITED STATES NATIONAL MUSEUM. [1885. 



EXPLANATION OF PLATE XXI. 



Fig. 1. Head of Hesperomys Truei,$, life size. From the specimeu captured at Fort 

 Wingate, N. Mex., March 16, 1885. 



Fig. 2. Head of Hesperomys leucopus sonoriensis, $ , life size. From the specimeu 

 taken at Fort Wingate, N. Hex., May 16, 1885. 



Fig. 3. Head of Ochetodon hvmilis, $ , life size. From the specimen taken at Fort 

 Wingate, N. Mex., June 30, 1885. 



Fig. 4. Superior aspect of the cranium of Neotoma floridana, $ , natural size. Speci- 

 men taken at Fort Wingate, N. Mex., January 11, 1885. 

 n. mx. Nasal process of the superior maxilla. 



Fig. 5, Superior aspect of the cranium of Hesperomys Trnei, $ , natural size. TyjDe 

 specimen. 



n. mx'. Nasal process of the superior maxilla. 



Fig. 6. Left lateral view of mandible of Neotoma floridana, natural size. Same 

 specimen as Fig. 4. 



Fig. 7. Left lateral view of mandible of Hesperomys leucopus, natural size. Speci~ 

 men 4856, National Museum Collection. 



Fig. 8. Left lateral view of mandible of Hesperomys Truei, natural size. Same 

 specimen as Fig. 5. 



(All the figures drawn from nature by the author.) 



