148 DAVENPORT ACADEMY OF NATURAL SCIENCES, 



nest is attached to the rafters of old barns, or is placed under a bridge. 

 The eggs are laid the last week in May. In the spring when it first 

 arrives, it is seen skimming over the surface of ponds in company with 

 other swallows, and is not unfrequently noticed Hying over the fields at 

 some distance from dwellings. 



Genus TACHYCINETA Cabanis. 



[B 227, R 155, C 160, U 614.] 

 Tachycineta bicolor (Vieill.). Tree Swallow. Summer resident; 

 rather common. Arrives about the first of May, and departs about 

 the middle of September. Nests in cavities in trees, and boxes. In 

 the spring it appears in company with the barn swallow. 



Genus CLIVICOLA Forster. 

 [B 229, R 157, C 163, U 616.] 

 Clivicola riparia (Linn.). Bank Swallow. Summer resident; 

 breeds abundantly in all parts of the State. A few miles above Mus- 

 catine a large colony of these birds occupies the perpendicular side of 

 a deep excavation in a hill-side; the bank is literally honeycombed, 

 and thousands of swallows flying about reminds one, at a distance, of a 

 swarm of bees. Considerable confusion appears to exist among many 

 observers, who confound this with the following species. 



Genus STELGIDOPTERYX Baikd. 

 [B 230, R 158, C 164, U 617.] 

 Stelgidopteryx serripennis (And.). Rough-winged Swallow. Sum- 

 mer resident; abundant, arriving about the middle of April. In cen- 

 tral Iowa, especially in Polk and the contiguous counties, this species 

 is quite abundant, almost to the exclusion of the bank swallow. The 

 nests are usually built in the alluvial banks of the streams, or in the 

 sides of gravel pits and in road-cuts. Several years ago, three nests 

 were taken in a cut which afforded a bank less than three feet in height. 

 In the spring after its arrival, it may be seen flying about in the vicinity 

 of the banks which it has selected for its future home. Usually 

 there are ten to fifty or more pair occupying, with a few bank 

 swallows, a cliff on a bend in a river. About the first or second 

 week in May they commence excavating, for a nest, a hole to the 

 depth of two or three feet. At the terminus of the excavation is placed 

 the # nest, which is usually composed of bits of hay and grass taken from 

 a barn-yard. By the first of June the full complement of eggs — from 

 five to seven — is. laid; the period of incubation is about two weeks. 

 A little careful observation will enable almost any one to distinguish 

 between this species and preceding, even when on the wing and at 

 some distance. 



