APPENDIX. 423 



C. A KEY TO THE EGGS OF MASSACHUSETTS. 



This list, limited to the eggs previously described in this 

 volume, is not wholly reliable, since several birds, not yet 

 known to have actually bred in Massachusetts, may do so 

 occasional!} 7 , and since eggs vary greatly, often presenting 

 abnormal forms, or forms like those of other kinds. 



1. Eggs Unmarked. 



A. Color, white.i 



(a). Laid in holes of trees (or posts and stumps). 



1. > 1-25X1-00. Screech Owl. 26, V. 



(2). Av. l-OOX'90. Bird entirely brown and white. Acadian Owl. 26, IV. 

 3. > 1-00X80, < 1-25X1-00. Bird not red-headed. Pigeon Woodpecker. 25.1, 

 (4). >rOOX-80,<l-2f>Xl-00. Bird red-headed. Red-headed Woodpecker. 25,11. 

 (5). Av. -95X-80. Bird; crown scarlet, upper breast black. Yellow-bellied Wood- 

 pecker. 25, III. 



(6). Generally > -80X 65. Bird > 9 in., (chiefly) black and white. Hairy Wood- 

 pecker. 2.%V, A. 



7. Generally < -80X'65. Bird < 7 in., r (chiefly) black and white. Downy Wood- 

 pecker. 25, V, B. 



(8). Av. -75X-55. Bird tretallic green above. White-bellied Swallow* 12, III. 

 (9). Av. -80X60, usually blue. Bird with chestnut breast. Blue Bird.* 2,1. 

 [The Martins and Chimney Swifts no longer ( ?) build in stumps (etc.), in N. E.] 



(6). Nests built in trees (or bushes), but not in holes. 



(1). > 2-75X2 25. White, very impure or dirty. Bald Eagle. 27, VIII. 



2. 2-25 long (or more). Not often pure white. Great Horned Owl. 3 26, VI. 



3. 2-00 long or less; subspherical. Barred Owl. 26, III, B. 



4. Av. 1-90X1-50. Not spherical. Generally bluish; often marked. Cooper'* 



Hawk. 27, III, B. 



5. Av. 1-60X1-35. Nearly spherical. Long-eared Owl. 26, II, A. 



6. Av. 1-45X1-20. Generally marked. Sharp-shinned Hawk. 27, III, A. 



7. Av. 1-50X1-10; elliptical. Nest loose and frail. Wild Pigeon. 29,1. 



8. Av. I-IOX'80. Nest loose and frail. Carolina Dove. 29,11. 



9. Av. -75X'55, often bluish. Nest in bush or shrubbery. Indigo Bird. 15, XX. 

 10. Av. -63X-50, bluish. Nest in bush or shade-tree. Goldfinch. 15, IV, A. 

 (11). Av. -70X'55. Pure wh. Nest in woods ( ?). Yellow-bellied Flycatcher. 19,V, C. 

 12. Av. -62X'50. Nest in (woods) orchard or shade-tree. Bird olive-gray above. 



Least Pewee. 19, V, B. 



1 Many water-birds lay large white eggs, some in hollow trees, but these are all 

 tinged with blue, green, or buff. Some of the petrels, however, lay a single small 

 pure white egg, but none do so here. 



2 The nests of these birds are usually well lined, the Blue Bird's generally most 

 warmly; those of the woodpeckers are rarely so. 



8 See B, (a), (1). 



