202 Field Columbian Museum — Zoology, Vol. III. 



A few feet below the spring the tree yuccas, mescal, and several species of 

 cacti occur abundantly." Two days were passed here on the way to San 

 Felipe and four nights on the return trip. Canon Esperanza, where two 

 days were passed, was the next stopping-place. It is situated " on the des- 

 ert slope of the mountains and drains into the San Felipe Valley. The 

 mountains near the canon's mouth rise almost vertically from the desert 

 to altitudes of 8,000 to 10,000 feet. The floor of the valley is about 

 1,000 feet above sea level. Near the mouth large granite boulders cover 

 the surface of the ground, but further out nothing but white sand is to be 

 found. Near the base of the mountains the country is very bushy, being 

 covered with a scattered growth of small spreading trees, mostly mes- 

 quite, palo verde, ironwood and giant cereus cactus. The whole region 

 is sandy, except the beds of alkali lakes. The only water is that found 

 in the canons of the San Pedro Martir Mountains and a few tanks in the 

 higher desert ranges. The pinon belt comes down the mountain slopes 

 to within about 1,500 feet of the base. Two days were passed here on 

 our way out and two on our return from San Felipe." This last place, on 

 the Gulf of California, was the next camping-ground. The region 

 about San Felipe Bay is " a level white sand desert, flanked on the west 

 by a rather low range of mountains, and on the north by a similar range 

 extending down to the bay, forming its northern point and separating it 

 from the Colorado Desert farther north. The vegetation about the bay is 

 scanty, the creosote bushes and a few mesquite and copal trees comprising 

 most of it. Cacti are rare in this region." Two weeks were passed and 

 a considerable collection was made. From San Felipe Mr. Heller was 

 obliged to return to Ensenada, as his sixty days would have expired by 

 the time he could reach the Pacific coast, and he therefore retraced his 

 steps, stopping at some of his previous camps. On his arrival he learned 

 that instructions had been forwarded to the authorities from the Secre- 

 tary of State, Mexico City, at the request of this Institution, to allow 

 him to carry arms, without any time limit being mentioned, anywhere in 

 Mexico he chose to visit. This simplified matters greatly, for it would 

 have been impossible for him to explore the mountains, as he subse- 

 quently did, if he had been compelled to return to the coast every sixty 

 days. After various delays from different causes Ensenada was again left 

 on the 7th of May, the intention being to proceed along the western 

 edge of the San Pedro Martir Mountains to their southern border and 

 reach the coast at San Quentin, and then later, during the great heat of 

 summer, to penetrate among the higher peaks of the range. The first 

 camp out from Ensenada was Trinidad, to obtain the burros that had 

 been left there on the return journey from San Felipe, and to procure 

 additional ones. The route was then continued " along the west edge of 



