102 NORTH AMEEICAN OOLOGY. PART I. 



HIRUNDO THALASSINA. 



Hirundo thalassina. Swains. Syn. Mexican Birds, Phiios. Mag. 1827, p. 366. 

 " " AuD. Orn. Biog. IV, 1835, 497, pi. ccclxxxv, figs. 4 and 5. 



" " BoNAP. Geog. and Comp. List, 1838, p. 9. 



" " AuD. Syn. 1839, p. 36. 



" Birds of Am. I, 1840, 186, pi. xlix. 

 VuLG. — The Violet-Green Sicallow. 



The first knowledge I possessed of the markings of the egg of this species was 

 supplied me by Mr. Audubon, in the drawing of an egg obtained by Mr. Nuttall in 

 Oregon. But a very limited knowledge is as yet in our possession in regard to its 

 habits, its distribution, or general peculiarities. For nearly all that we do know, 

 we are indebted to the observations of Messrs. Townsend and Nuttall. The latter 

 met with this SA\'allo-\v on a branch of the Colorado. They were in great numbers, 

 associating with the Cliff Swallow. He states that they occupied the old nests of 

 the latter, in preference to constructing their own. He also conjectured, probably 

 without good reason, that they breed in trees, after the manner of the White-bellied 

 Swallow. 



Mr. Townsend's account of this Swallow diifers materially. He also speaks of 

 finding them breeding on the banks of the Colorado, Avhere, he adds, it nests along 

 its margin on bluffs of clay, to which it attaches a nest formed of mud and grasses 

 resembling that of the Cliff Swallow, but wanting the pendulous neck. It is quite 

 probable that the nests supposed by Mr. Nuttall to be old nests of H. lunifrons 

 Avere in reality constructed by this species for their own use. Mr. Townsend speaks 

 of the eggs as having been four in number, and of a dark clay-color, with a few 

 sjjots of reddish-brown at the larger end. This hardly corresponds with the drawing 

 of the egg obtained by Mr. Nuttall, nor yet with the one represented in the plate. 

 Mr. Townsend adds, that it is also abundant on the Columbia River, and that it 

 there breeds in hollow trees. He does not say whether this is the result of his own 

 observations, or is given on the authority of others.' 



The ground color of the egg of this bird, as given in the painting by Mr. Audu- 

 bon, is a light stone-color, or clayish-white, — not a "dark clay-color," as Townsend 

 describes it ; and the spots, which are of varying light and dark shades of reddish 

 and purplish brown, are scattered over the whole egg, instead of being confined to 

 the larger end. Its shape is sub-oval, and more than usually oblong. It measures 

 f I of an inch in length by ^'g in breadth. The egg represented (Plate V, fig. 74) 

 vi^as obtained by Dr. Thomas H. Webb when engaged on the Mexican boundary 

 survey. The nest is described by him as built on the side of a cliff, open at the 

 top, and resembling the nest of the common Hirundo rufa. He obtained it on the 

 bank of Mulberry River, near Mimbres, New Mexico. It measures {| of an inch 

 in length by -^-^ in its greatest breadth. Its shape is an oblong oval, pointed at 



' Dr. Cooper corroborates this statement as within his own experience. 



