1914.] 



CEANIAL MEASUEEMENTS. 



81 



contracted anteriorly; palatal foramina short, not reaching plane of 

 molars. 



Measurements. — Type (9 ad.): Total length, 187; tail vertebrae, 

 117; hind foot, 20. Skull: (See table below). 



Remarks. — This form is closely related to microdon, differing chiefly 

 in paler coloration. 



Specimen examined. — One, the type. 



Average cranial measurements of Reithrodontomys. 



Species. 



Localities. 



Greatest length. 



Breadth of brain- 

 case. 



Length of nasals. 



Width of outer wall 

 of anteorbital for- 

 amen. 



19.4 



9.3 



6.4 





L9 



19.4 



9.2 



6.4 





L7 



19 



9.3 



6.9 





2.1 



19.5 



9.6 



7.3 





2.2 



19.3 



9.3 



7.2 





L9 



20 



9.4 



7.9 





2.1 



20.7 



9.9 



7.5 





2.1 



22.1 



10.5 



8.5 





2.2 



20.6 



10.1 



7.8 





2.1 



20.8 



9.9 



8 





L9 



20.2 



9.8 



7.7 





2 



20.7 



10.2 



8.1 





1.9 



21.6 



10.3 



8.2 





2.2 



22.5 



10.4 



8.7 





2.2 



22.4 



10.5 



8.5 





2.3 



20.4 



9.9 



7.5 





1.9 



20.5 



9.9 



8.2 





1.9 



19.8 



9.5 



7.6 





1.7 



21. 9 



10. 3 



8. 8 





2. 3 



2L2 



io!2 



7! 6 





2!l 



20.8 



10.1 



7.5 





2 



21.6 



10.3 



8.2 





2 



21.9 



10.2 



8.3 





2 



01 Q 



iU. 0 



0. 0 





2 



22.2 



10.5 



8.5 





2.2 



21.8 



10.5 



7.8 





L9 



23.4 



10. 7 



9.4 





2.1 



22.4 



10.6 



8.5 





2.1 



22.4 



10.7 



8.1 





2 



21.2 



10 



8 





1.8 



22.3 



10.4 



9 





2.2 



19.5 



10.3 



7.7 





1.8 



23.8 



11 



9.3 





2.1 



23.6 



10.9 



9 





2.1 



23.9 



ILl 



9.1 





2.2 







9 





2.1 



23.2 



1L3 



10.1 





1.9 



22.6 



11 



8.4 





2.2 



23 



10.6 



9 





2.1 



22.5 



10.7 



8.2 





L8 



21 



10.5 



7.8 





1.8 



22.7 



1L4 



7.9 





1.9 



24.9 



11.8 



8.9 





2 



24.3 



n.7 



9.3 





2.2 



24 



1L5 



9.3 





2.2 





10.7 



9 





2 



23.2 



11 



9.1 





2 



23.1 



11.3 



8.7 





1.8 



24 



11.5 



9.5 





1.7 



23.7 



1L7 



8.1 





1.7 



22.5 



11.2 



7.6 





L4 



24.2 



11.5 



9 





L8 



2L6 



10.5 



7.5 





L7 



25.7 



12.5 



9.1 





1.7 



25.2 



12.1 



9.6 





1.7 



25.4 



11.6 



8.8 





1.9 



22.3 



n.i 



8.5 





1.3 



22.3 



11.4 



7.8 





1.3 



R. humuUs liumulis 



E. liumulis impiger 



R. liumulis merriami 



R. albescens albescens 



R. albescens griseus 



R. montanus 



R. megalotis megalotis 



R. megalotis aztecus 



R. megalotis dychei. 



R. megalotis nigrescens — 

 R. megalotis longicaudus . . 

 R. megalotis peninsulss.. . 



R. megalotis cinereus 



R. megalotis saturatus 



E. megalotis alticolus 



R. megalotis arizonensis. . . 



R. megalotis zacatecse 



R. amoles 



R. catalinse 



R. raviventris raviventris. . 

 R. raviventris halicates . . . 

 R.fulvescens fulvcsctsTis 



R.fulvescens tenuis 



R.fulvescens intermedius.. 

 R.fulvescens aurantius. . . 



R.fulvescens difficilis 



R.fulvescens toltecus 



R.fu Ivescens helvolus 



R.fulvescens cliiapensis. . . 



R.fulvescens nelsoni 



R.fulvescens mustelinus.. 



R. amomus 



R. otus 



R. r ufescens rufescens 



R. rufescens luteolus 



R. alleni 



R.coUmae colimx 



B. colimse nerterus 



R. dorsalis 



R. australis australis 



R. australis modestus 



R. levipes 



R. Mrsutus 



R. chrysopsis chrysopsis. . . 



R. chrysopsis tolucse 



R. chrysopsis orizabss 



B. perotensis 



R. mexicanus mexicanus . . 

 R. mexicanus goldmani.. . 



R. mexicanus cherrii 



R. milleri 



R. soderstromi 



R. gracilis 



R . tenuirostris tenuirostris 



R. tenuirostris aureus 



R. creper 



R. microdon microdon 



R. microdon albilabris 



North Carolina; South CaroUna; Georgia. - , 



Yv'est Virginia: White Sulphur Springs 



Texas: Austin Bayou; Louisiana: Lafayette, 



Nebraska; South Dakota 



Texas: San Antonio, San Angelo 



Colorado: San Luis Valley 



New Mexico (southern); Chihuahua 



New Mexico: La Plata, Aztec, Guadalupita. 



Kansas: Lawrence^ Onaga 



Idaho: Payette, W eiser, Nampa 



CaUfornia: Vicinity of San Francisco Bay. . 



Lower California: San Quintin, Rosario 



Puebla: Chalchicomula 



Vera Cruz: Las Vigas 



Oaxaca: Cerro San Felipe 



Arizona: Chiricahua Mountains 



Zacatecas: Valparaiso Mountains 



Queretaro: Pinal de Amoles 



Cahfornia: CataUna Island 



Cahfornia: San Francisco Bay 



CaUfornia: Petaluma (marshes) 



Sonora: Oposura, Pro\i.dencia Mines 



Sinaloa: Mazatlan, Sinaloa, Escuinapa 



Texas: Brownsville; Tamauhpas 



Texas and Louisiana 



Vera Cruz: Orizaba, Jalapa 



Mexico: Tlalpam, D. F 



Oaxaca: Oasaca 



Chiapas: Canjob 



CoUma: CoUma 



Oaxaca: Llano Grande 



Oaxaca: Reforma 



Jahsco: Sierra Nevada de CoUma 



Vera Cruz: Jalapa, Jico 



Oaxaca: Juquila 



Oaxaca: Mountains near Ozolotepec 



Jalisco: Sierra Nevada de CoUma 



....do 



Guatemala: Calel 



Costa Rica: Volcan Irazu 



Nicaragua: Jinotega 



JaUsco: San Sebastian 



JaUsco: Ameca 



Mexico (State) and Morelos 



Mexico: Volcan Toluca 



Puebla: Mount Orizaba 



Vera Cruz: Cofre de Perote 



Vera Cruz; Oaxaca; Guatemala.... 



Puebla: Metlaltoynca 



Costa Rica: La Carpintera, San Pedro 



Colombia: Munchique 



Ecuador: Quito 



Yucatan: Chichen Itza; Campeche: Yohal- 

 tun. 



Guatemala: Todos Santos 



Guatemala: Calel 



Panama: Volcan de Chiriqui 



Guatemala: Todos Santos, Volcan Santa 

 Maria. 



Oaxaca: Cerro San FeUpe 



28657°— 14 6 



