36 TJ. S. p. R. R. EXP. AND SURVEVS — ROUTE TO CALIFOKNIA. 



HIRUNDO EUFA, V i e i 1 1 .—The Barn Swallow. 



Jlirundo ru/a, Nutt. Orn. vol. I, p. 601. 



Hirundo americana, Wii.s. Am. Orn. vol. V, pi. 38, figs. 1 — 2. — Aud. B. of A. Fol. pi. 173. ' 



Hirundo natica, Aon. Oct. vol. I, p. 181, pi. 48. 



Abundant throughout California, New Mexico, and Texas. 



HIRUNDO BICOLOR, Vieill.— The White-bellied Swallow. 



Hirundo bicdor, Vieill. Ois. Am. Sept. vol. I, p. 61, pi. 31. 



Abundant. 



HIRUNDO LUNIFRONS, Say .—The Cliff Swallow. 



Hirundo ftdm, Bonap. Am. Orn. vol. I, p. 63, pi. 7, fig. 1.— Aud. B. of A. Oct. vol. I, p. 177, pi. 47.— Ib. FoI. pi. GS. 



Abundant, building its nest in the cities under the eaves of houses, and in the mountains 

 under the shelving rocks. I found it abundant, also, in New Mexico and Texas. This species, 

 formerly considered as one of our western birds, has within a few years commenced its 

 migrations to our northern States, gradually extending them year after year further south, until 

 it has become in Pennsylvania a regular visitor, like the other common species of the same genus, 

 arriving in spring, incubating, and taking its departure in the fall for more genial climes. 



HIRUNDO THALASSINA, Swains.— Violet Green Swallow. 



ffirundo thalcuiina, Sw. Philos. Mag. 1827, p. 366.— Aud. B. of A. Oct. vol. I, p. 186, pi. 49.— Ib. Fol. pi. 385. 

 Baird, Gen. Kep. IX. 



I met with this beautiful little species occasionally during our survey, but always on its 

 migrations southward, it being the fall of the year. On the summit of the Tejon Pass I shot 

 several towards dusk as they flew circling in the air in pursuit of insects, a manoeuvre which 

 they are in the habit of performing at this season every evening before retiring to rest. Among 

 these large flocks of swallows I remarked a small black swift, {Acanlhylis,) but was unable to 

 procure it. While visiting Dr. T. 0. Henry, U. S. A., at Fort Thorne, New Mexico, we observed 

 many of these swallows flying over a pond on the edge of the Rio Grande river. Its migrations 

 extend over California, and it is one of the most abundant species in Oregon. 



COTYLE RIPARIA, L i n n.— The Bank Swallow. 



Hirundo riparia, Wils. Am. Orn. vol. V, p. 46, pi. 38, fig. 4.— Aon. B. of A. Oct. vol. I, p. 187, pi 50. 



Abundant. 



COTYLE SERRIPENNIS, Aud.— Rough-winged Swallow, 



Hirundo terripmnis, Aud. Synopeie, p. 37.— Ib. B. of A. Oct. vol. I, p. 193, pi. 51.— Ib. Orn. Biog. vol. IV, p. 593.— 

 Baird, Gen. Rep. IX. 



Abundant. I observed while in Texas, in this species, a curious instance of the manner in 

 which birds accommodate themselves to the localities in which they sojourn. The river banks, 

 a favorite resort with them around San Antonio, possess in few spots only the conditions reijuisite 

 for their nidification, being either insufficiently steep to afford them opportunities of sinking 

 their holes, or being in their more abrupt parts composed of a hard rocky earth, into which they 



