32 New Swallo%o from Western United /States. 



claw, 13.7. The folded wing, in the recently-killed specimen, extended 

 13 mm. beyond the tail. Top of head parrot green. Nape with a 

 narrow collar of Indian purple. Whole of back bottle green, faintly 

 glossed with violet when viewed in a certain light. Rump and upper 

 tail-coverts, violet, shaded with plum-purple. Wing and tail quills, 

 black, strongly glossed with indigo above, their under surfaces slate- 

 gray; wing-coverts violet, edged with parrot green. Two white patches 

 on the rump, one on each side; these, in life, are brought close 

 together so as to form an apparently continuous white band across the 

 rump. Under surface all white, except the flight-feathers, this extend- 

 ing to the hind neck and ear-coverts. Iris brown. Bill, brownish black. 

 Feet, dark brown; claws, black. 



Adult female. — Similar to the male, bvit smaller, with color much 

 duller, the white of ear-coverts and hind neck much mixed with brown- 

 ish gray. 



F(9«?i^.— Similar to the same stage of Tachycineta bicolor (Vieillot) 

 but with feathers of lower parts grayish beneath the surface; easity dis- 

 tinguished by its smaller bill. 



Comparison. — Adult male. No. 143,516, U. S. National Museum collec- 

 tion, taken on Mt. Popocatepetl, Mexico, February 23, 1893, by E. W. 

 Nelson, a typical example of Tachycineta. thalassina (Swainson), measures 

 as follows: wing, 127 mm.; tail, 58; exposed culmen, 5.6; tarsus, 11; 

 middle toe with claw, 15. The whole back is of a color intermediate 

 between Indian purple and violet, changing to green if viewed in a 

 certain light. The rump and upper tail-coverts are bottle green. 



GeograpMc range. — Western United States, from the eastern base of 

 the Rocky Mountains to the Pacific, north to British Columbia and 

 Alaska, (breeding throughout this range) south, in winter, to Guate- 

 mala and Costa Rica. 



Remarks. — Breeding birds of the present form from Arizona and 

 northern Mexico suggest — by larger size and occasional green feathers 

 in the rump and upper tail-coverts — bvit by no means prove intergrada- 

 tion with Tachycineta thalassina. I am indebted to Dr. Louis B. Bishop 

 for specimens collected by him on the Yukon River, in July, 1899. 

 These are small, an adult male measuring: Wing, 112 mm.; exposed 

 culmen, 5. 



