VOL. IV.] Birds of San Pedro Martir. 229 



Several days were spent at various camps between this point 

 (7000 feet) and the gulf slope which was not reached until May 

 23. The return march was taken up May 27 and San Diego 

 reached June 7, 



During our southward march the migration was at its height 

 and at the time that we left the higher parts of the mountain new 

 arrivals were seen almost daily; it is not improbable that among 

 these late arrivals some Sonoran species might have been found 

 had our time permitted a more thorough investigation. It is 

 probable, however, that most of the species inhabiting the pine 

 belt were noted. The region embraced in the name of San Pedro 

 Martir consists of a high plateau of about sixty-five or seventy 

 miles in length by twenty in width, lyiog about twenty miles 

 from the gulf, and with its greatest extent parallel with that 

 coast. Most of the plateau would be embraced within the limits 

 of 30° and 31° north latitude. The northern end rises to a 

 height, in one or two peaks, of 12,500 feet, estimated, and from 

 that point the ridges and peaks drop away by degrees until at 

 the southern end they merge into the low, barren hills, common 

 to the peninsula at this point. The east and northern slopes, 

 however, are very steep and rocky, with only two or three 

 almost impassable trails, while the eastern side presents along its 

 entire length in many places a sheer precipice for thousands of 

 feet. 



A series of large open meadows is found at an elevation of 

 8000 to 8500 feet, surrounded by rough, rocky ridges and heavy 

 pine timber. These ridges are characteristic of the entire region 

 which is composed of soft, friable syenite, the softer parts of 

 which in crumbling away have left huge masses of gigantic 

 boulders forming ridges, in many cases impassable, A growth 

 of yellow pine, Pinus Jeffreyi, covers the ridges and slopes as low 

 as 7000 feet altitude, where it gives place to a belt of scattered 

 piiions, P. Parryana, reaching to 6000 feet or less, a growth of 

 Manzanita and Ceanothus covers all of the slopes and ridges 

 where it is too rocky for the pines to obtain a foot-hold, and in 

 many places a small shrub oak was abundant. The streams, 

 which were abundant, were all fringed with willow and a few 

 Aspans were seen in some localities. Arising as this region 



