96 



but nearer to this than any other form" (Stone and 

 Rhoads). 



101. Amphispiza bilineata deserticola. Desert Sparrow. — 



Two or three were observed, and one collected in the 

 Cocopahs by Rhoads. ^'This is a bird of the upland 

 deserts; not one was seen in the riparian belt" (Grin- 

 nell, 1914, 173). 



102. Melospiza melodia fallax. Desert Song Sparrow. — 



Song Sparrows were not uncommon along water 

 courses around Mexicali, and we occasionally saw or 

 heard them in the delta. Examples were collected 

 by Rhoads. 



Some or all of the birds observed may, of course, 

 have been referable to M. m. saltonis Grinnell. 



103. Pipilo aberti. Abert's Towhee. — A bird of the outer 



associations of the riparian belt, and probably a 

 breeder in the region. Specimens were obtained by 

 Rhoads in both the delta and the mountains. 



104. Guiraca caerulea lazula. Western Blue Grosbeak. — 



On our first trip to the delta we saw no Blue Grosbeaks, 

 the species having probably not yet arrived from the 

 tropics. But when Mrs. Murphy and I started down 

 the river from Volcano Lake, on April 26, we found 

 these birds swarming in the sandy openings west of 

 where the twisting Hardy passes the mud volcanoes. 

 Here they were feeding on the ground in company 

 with Mourning Doves. A male collected on that 

 date had not yet lost the brownish edgings of the 

 feathers on nape and back. 



105. Hirundo erythrogastra. Barn Swallow. — Several seen 



in Mexican on April 24. 



106. Iridoprocne bicolor. Tree Swallow. — Several flocks 



seen by Rhoads, and one specimen collected. 



107. Tachycineta thalassina lepida. Northern Violet- 



green Swallow. — ''Of large flocks seen some seemed 

 to be this species" (Rhoads). This swallow is not 

 uncommon in the Imperial Valley in winter. 



