478 APPENDIX. 



known. Hence the following diagnoses as well as the rearrange- 

 ment of the New England records are to some extent tentative. 

 The diagnoses are based partly on those in Mr. Ridgway's " Manual 

 of North American Birds " and partly on the results of a personal 

 study of about one hundred and thirty specimens, of which nearly 

 ninety are contained in the collection of the United States National 

 Museum. In connection with the records I have intentionally ig- 

 nored all reports of Gyrfalcons said to have been seen, or supposed 

 to occur, in New England, and have mentioned only specimens that 

 have been actually taken and are known to be still in existence. 



FALCO ISLANDUS. White Gyrfalcon. 



Prevailing color pure white ; the under tail-coverts always, the 

 thighs usually, unspotted ; the remainder of the plumage ordinarily 

 more or less marked with dusky or slaty ; but the crown, hind neck, 

 and entire lower parts nearly or quite immaculate in some old birds. 



The only White Gyrfalcon known to have been taken in New 

 England, or, indeed, in the United States, is a specimen in my col- 

 lection shot at South Winn, Maine, about October 8, 1893, by a 

 young man named Wyman, who sent his prize to Mr. John Clayton, 

 a taxidermist at Lincoln, Maine, by whom it was mounted. This 

 specimen is a young bird, apparently a male, but unfortunately the 

 sex was not definitely ascertained. Mr. Ridgway, who has recently 

 examined it, agrees with me in considering it an undoubted repre- 

 sentative of F. islandus, although it is somewhat darker than aver- 

 age examples of this form. 



FALCO RUSTICOLUS. Gray Gyrfalcon. 



Lower tail-coverts always more or less marked with dusky ; top 

 of head much streaked with white, often with white prevailing ; tail 

 crossed by alternating dark and white or whitish bars usually of 

 about equal width and sharply contrasted ; remainder of upper parts 

 conspicuously barred or spotted with grayish white, or light buffy on 

 a dark ground; under parts barred (in old birds) or striped (in 

 the young) with dusky on a whitish ground. 



It is not improbable that the Gray Gyrfalcon will have to be ex- 

 cluded from New England lists, for the specimen in the Museum of 

 Comparative Zoology at Cambridge, taken near Providence, Rhode 

 Island, in the winter of 1864-65 (Allen, Am. Nat., Vol. Ill, 1869, 

 p. 513), and so often mentioned by writers as an example of this 

 form, is really an almost typical F. r. gyrfalco. There is, however, 



