V,I iS* m ] Bishop, New Birds from North Dakota. 1 29 



and the bears. Neither of these quadrupeds has the gradation 

 of color, nor the standing or crouching habit. They are both noc- 

 turnal, and therefore do not need either gradation or crouching 

 for concealment. 



It is plain, then, that while nature undeniably completes the 

 concealment of animals by pitching their whole color-gradation in 

 a key to match their environment, the real magic lies in the gra- 

 dation itself from darkest above to lightest below, wherever this 

 gradation is found. This is why it is so hard to see the Partridge 

 in the tree, the Sandpiper on the mud, or the tiger crouching in 

 the jungle. 



DESCRIPTIONS OF A NEW HORNED LARK AND 



A NEW SONG SPARROW, WITH R EM ARKS 



ON SENNETT'S NIGHTHAWK. 



BY LOUIS B, BISHOP. 



The birds upon which this paper is based were collected by 

 Mr. W. H. Hoyt and myself in Towner and Rolette Counties, 

 North Dakota, during the spring and summer of 1895. Both 

 counties belong to the prairie region, are practically treeless, cul- 

 tivated only partially, and dotted with lakes and sloughs of vary- 

 ing extent. The Turtle Mountains, part of which lie in the 

 northern part of Rolette County, and through which passes the 

 Manitoba boundary, are utterly different in character. They con- 

 sist of hills rising a few hundred feet above the rolling prairie, 

 contain numberless small lakes and ponds, and are covered with 

 a dense growth of deciduous trees. 



My thanks are due to Mr. Hoyt for the use of his series of 

 skins of the races described, and to Dr. Allen and Mr. Chapman 

 of the American Museum of Natural History, and to Mr. Ridgway 

 of the Smithsonian Institution, for the privilege of comparing my 

 birds with the collections of the respective museums. 



