50 NA T URE-STUD Y RE VIE W 1 15 :2— Feb. , 1919 



1. Under 4 inches inside diameter. . . . robin 



2 . Over 4 inches inside diameter . . bronzed crackle 

 BB. Outer layer of mud, some grasses 



1. Open at top, cup-shaped barn swallow 



2 . Open at side, gourd-shaped cliff swallow 



BBB. Outer layer of moss and mud phcebe 



VIII. WITH AN OUTER COVERING OF LICHENS, SADDLED ON BRANCH 



A. Very small, less than i}4 inches outside diameter. . . . . ; 



RUBY-THROATED HUMMING BIRD 



AA. Larger, over i}4 inches outside diameter 



1 . Very deep, over i ^ inches 



*BLUE-GRAY GNAT CATCHER 



2 . Shallow, under i y^ inches wood pewee 



IX. MOSTLY OF BARK, FIBERS, AND ROOTLETS, WITH OR WITHOUT 

 HORSEHAIR LINING 



*A. Small woodland nests, usually in evergreens, less than 

 2 inches in diameter (seldom found) . . pine warbler, 



BLACK-THROATED BLUE WARBLER, MAGNOLIA WAR- 

 BLER, BLACK-THROATED GREEN WARBLER, PURPLE 

 FINCH, BLACKBURNIAN WARBLER 



AA. Small woodland nests, less than 2 inches in diameter, 

 usually in blackberry or similar bushes 



CHESTNUT-SIDED WARBLER 



AAA. Orchard or woodland nests, over 2 inches inside diameter 

 B. Usually thin flimsy structures 



1 . Little or no lining, usually in high bushes 



ROSE-BREASTED GROSBEAK 



2 . Considerable lining, usually in trees 



SCARLET TANAGER 



BB. Thick, well-formed structures with some cotton or wool 



1. Shallow, about i inch deep. kingbird 



2. Deeper, about 1^2 inches deep cedar waxwing 



X. MOSTLY OF grasses, ROOTLETS, STRAWS, AND LEAVES, USUALLY 

 WITH HORSEHAIR IN THE LINING, AND NOT SPHERICAL 



A. With many leaves, placed in weeds, ferns, or low bushes . . 



INDIGO BUNTING 



