12 NORTH AIMERICAN OOLOGY. TAET I. 



Avitli one from Greenland, in the collection of the Philadelphia Academy (fig. 12). 

 If these variations are specific, as I presume they are, the eggs belongmg to Mr. 

 Yarrcll, described by him as those of the European species (Jf. islandicus), are 

 l^robably those of the American bird. The same were figured by Mr. Hewitson ; 

 and as neither of these naturalists recognizes the two Hawks as distinct species, 

 they were not likely to be on their guard in reference to any specific variations in 

 their eggs. In European collections, the eggs of both species have been confounded 

 with each other, all passing as undoubted eggs of H. islandicus, precisely as those 

 of the American Fish-hawk (Pandion carolinensis) are unwarrantably confounded 

 Avith those of the European Osprey (^Pandion haliceftis), and the two are even re- 

 garded as identical in Hewitson's Oology. 



The egg of the H. sacer is slightly larger than that of the H. islandicus, and the 

 predominant color of its markings is a deep reddish-brown, very generally and 

 nearly equally diffused over its surface, concealing the ground color, which is 

 lighter, and with a more yellowish shade. Its measurement is 2-fV inches in length 

 by lyt inches in breadth. 



Two specimens of the egg of H. islandicus, one from Norway and the other from 

 Iceland, measure, the first 2iV by l^, the latter 2tV by Irl inches. In both, the 

 ground color is a dirty yellowish-white. One is marked with spots, dottings, and 

 confluent blotches of yellowdsh-brown, interspersed with a few dashes of dark brown 

 in an increased proportion about the larger end. The other is marked in like 

 manner Avith light yellowish-broAvn, but much more sparingly, and so slightly and 

 uniformly, that, unless closely examined, it would seem to be of one uniform color, 

 and that a light brown, shaded with yellow. 



HYPOTEIORCHIS COLUMBARIUS. 



Falco columbarius, Linn. Syst. Nat. I, 1766, 128. 



WiLS. Am. Orn. II, 1810, pi. xv, fig. 3. 

 " " BoNAP. Syn. 1828, p. 38. 



Rich. & Swains. F. B. A. II, 1831, 35. 

 " " NuTTALL, Manual, I, 1832, 60. 



AuD. Orn. Biog. I, 1832, 466 ; V, 368, pis. Ixxv and xcii. 

 " " BoNAP. Geog. and Comp. List, 1838, p. 4. 



AuD. Syn. 1839, p. 16. 



" Birds of Am. I, 1840, 88, pi. xxi. 

 De Kay's Nat.' Hist. N. Y. I, 1844, 4, pi. iv, fig. 9. 

 Falco intermixlus, Daudin, Traite d'Orn. II, 1800, 141. 



?? Falco asalon, Rich. & Swains. F. B. A. IL 1831, 37. » 



Falco temerarius, Aitd. Orn. Biog. I, 1832, 381, pi. ixxv. 

 VuLG. — The Pigeon-Haick. Lillle Corporal Hawk. VEpervier de la Caroline (Briss.). 



It was at first my intention to omit at present giving any plate representing the 

 egg of this species, for the reason that I have been unable to decide with certainty 



