KEYES AND WILLIAMS BIRDS OF IOWA. 115 



Common spring and fall migrant arriving about the last of March 

 and passing southward again about the third week in October. It 

 often appears in Hocks of a score or more but is more commonly 

 noticed singly, or in companies of three or four, flying about over the 

 rivers in search of food. 



[B 664, R 669, C 77S, U 54.] 

 Larus delawarensis ( )rd. Ring-billed Gull. Common about the 

 lakes of Northern Iowa where it is said to breed. 



[B 668. 669, R 674, C 7S7. U 59.] 

 Larus franklinii, Sw. & Rich. Franklin's Gull. Migratory; rather 

 common. Doubtless breeds within the limits of the State. Mr. 

 J. W. Preston found this species breeding at Heron Lake, Minnesota, 

 a few miles from the northern boundary of Iowa. 



Subfamily STERXIX.K. Terns. 



Genus STERNA Linn.fis. 



Si bgenus STERNA. 



[B 691, 6S6, R 685, C 798, U 69.] 



Sterna forsteri Nutt. Forster's Tern. Migratory; common. In 



Central Iowa this species arrives about the first of May and is to be 



seen gliding gracefully over the rivers and small lakes in search of food. 



Genus H YDROCHELIDON Boie. 

 [B 695, R 693, C 806, U 77.] 

 Hydrochelidon nigra surinamensis (Gmel.). Black Tern. Spring 

 and fall migrant; abundant. Breeds, especially in the northern part of 

 the State about the grassy marshes and lakes. 



Order STEGANOPODES. Totipalmate Swimmers. 



Family PHALACROCORACID^:. Cormorants. 



(.ems PHALACROCORAX Brisson. 

 Subgenus PHALACROCORAX. 



[B 623, R 643. C751, U 120.] 



Phalacrocorax dilophus (Sw. & Rich.) Double-crested Cormo- 

 rant. Spring and fall migrant; common. Breeds in the northern por- 

 tion of the State. 



Family PELECANID^E. Pelicans. 



Genus PELECANUS Linnaeus. 



Subgenus CYRTOPELICAXUS Reichexbach. 



[B 615, R 640, C 74S, U 125.] 



Pelevanus erythrorhynchos Gmel. American White Pelican, Spring 



