VOL. IV.] Birds of San Pedro Martir. 237 



I found a small flock of these swifts fl\M'ng about over a pool of 

 water in company with Pctrochelidon and Tachycineta thalassina. 

 Later they were seen in several localities as far south as Colnett 

 and San Telmo; at this point they were quite common April 30, 

 and evidently migrating in company with swallows. A single 

 bird was seen at La GruUa May 18. 



Aeronaides melanoleuais. White-Throatkd Swift. Seen 

 in several valleys between Tia Juana and the base of San Pedro 

 but all evidently migrating. On top of the mountain they 

 appeared about our camp by dozens and could easily have been 

 taken in large numbers; they were mating and preparing to nest 

 in the high cliffs on the eastern side of the mountain where I 

 found them in i88g. A small colony was found nesting in the 

 cliffs at San Ysidro in May, 1887. On the Coronado Islands, 

 twenty miles from San Diego, a colony was discovered nesting in 

 a cliff overhanging the surf, not over thirty feet above the water, 

 but as usual the nests were inaccessible. 



Calypte cosfae. Costa's Hummingbird. Very abundant in 

 all of the valleys along the coast and base of the mountain; not 

 seen in the pines until about May 20; on May 28 they were 

 building at 7500 feet. 



Calypte annae. Anna's Hummingbird. A very common 

 resident of the coast region; not seen until May 15 at La 

 GruUa. As this species, as well as the preceding, nest in March, 

 sometimes as early as February in the lower valleys, it is not at 

 all improbable that the birds that w^e found in May on the mount- 

 ain had raised a brood before migrating. 



Tyraniiiis verticalis. Arkansas Kingbird. One was seen 

 May 15 at La Grulla, the only one seen in the pines; very 

 common in the coast valleys. 



Myiarclnis clncrascens. Ash-Throated Flycatcher. A 

 few were seen on San Pedro in 1889, and again the past season, 

 but it was not at all abundant; in the lower valleys it is more 

 common. A nest and set of four fresh eggs were taken from a 

 hollow on an elder in the Guadaloupe Valley, June 2. 



Sayoniis saya. Say's Phoebe. Quite common along the 

 base of the mountain and in all of the coast valleys below 4000 



