MAMMALS OP THE MEXICAN BOTJNDAEY. 107 



most of the mountain masses to the westward are composed, until, 

 in the Coast Range of California, it is replaced by fine-grained 

 granite. The Pajaritos also contain effusive rocks— rhyolite and 

 basalt — in abundance. 



Fauna of Nogales. — Owing to its location on the International 

 Boundary and the only railroad that enters Mexico west of the Rio 

 Grande, this station has attracted several trained field naturalists, 

 among them Mr. P. L. Jouy, to whose efforts I am mainly indebted 

 for the following list of the reptiles hitherto collected at Nogales : 



Sceloporus clarkii Baird and Girard. 

 Phrynosoma comutum (Harlan). 

 Anota modesta (Girard). 

 Eublepharis variegatus (Baird). 

 Cnemidophorus gularis gularin Baird 

 and Girard. 



Salvadora grahamicc Baird and Girard. 

 Rhtnochilus lecontei Baird and Girard. 

 JSlaps euryxanthus Kennicott. 



Terrapene sp. 



Kinosternon sonoriense Le Conte. 

 Gtenosaura multispinis Cope. 

 Crotaphytus coUaris (Say). 

 Crotapiiyitus wisUzenii Baird and 



Girard. 

 Vta stansliuriana Baird and Girard. 

 Vta symmetrica Baird. 

 Sceloporns jarrovii Cope. 

 Sceloporus torguatus poinsettii Baird 



and Girard. 



Station No. 43. — Corner Monument No. 127, where the Boundary 

 leaves the parallel 31° 20', 482 kilometers (300 miles) west of the 

 Rio Grande and 377 kilometers (234 miles) east of the Colorado 

 River; altitude, 1,592 meters (5,223 feet). This station is in the 

 midst of the Pajaritos Mountains, which rise from a base level of. 

 1,100 meters (3,609 feet) to the altitude of 1,836 meters (5,924 feet). 

 These rugged and little-known mountains have never received from 

 zoologists and botanists the attention which their importance merits. 

 I was absent in Texas when the detailed survey of them was made by 

 the International Boundary Commission. Subsequently, when at- 

 tached to the Monument-Building Party of the survey, they were but 

 hastily examined from Stations 42 and 44. Their flora is said to be 

 unusually varied, and the name, meaning " little birds " mountains, 

 is justified by the abundance of small birds during the breeding 

 season, which is doubtless due to the considerable number of water- 

 ing places. (Plate XII, fig. 1.) To the north of these mountains, 

 which extend from Monument No. 126 to Monument No. 142, is a 

 low, open country, which was crossed in several directions by myself 

 in going from Nogales to Tucson, from Tucson to Warsaw, and thence 

 to La Osa by way of Oro Blanco, Arivaca, and Tres Bellotas (= 3 

 Emory oaks)," and, later, from La Osa to Tucson and back by way 

 of Labaree, Pozo Bueno, and Buenos Ayres. 



Station No. 44. — Tumacacori Mission, on the Santa Cruz River, 

 Pima County, Arizona; altitude about 1,000 meters (3,281 feet). 



oin the canyons about Tres Bellotas some remarljably fine specimens of 

 Emory oak (Quercus emoryi) were seen. 



