Cuckoo-Shrikes 713 



erably near the water. They lay from four to six pure white eggs. Very soon 

 after the nesting season is passed they congregate in flocks often of vast size, 

 before beginning their southern migrations, such, for example, as the myriads 

 noted by Bachman, who "saw such an immense quantity of this species of bird 

 that the air was positively darkened. As far as the eye could reach, there were 

 Swallows crowded thickly together, and winging their way southward; there 

 must have been many millions ! " 



The Violet-green Swallow (Tachycineta) is smaller than the last, not attain- 

 ing a length of five inches, and has the upper parts a soft, silky green, bronze, 

 and violet, without gloss or sheen, while the entire under parts, including the 

 sides of the head and a fluffy patch on the flanks which tends to join its fellow 

 over the rump, pure silky white. The typical form (T. thalassina} occurs only 

 on the Mexican plateau, our common Violet-green Swallow (T. t. lepida) of 

 western North America from Mexico to the Yukon valley, Alaska, being a sub- 

 species, the only other form occurring in southern Lower California. The Violet- 

 green is a common bird in suitable localities throughout its range, spending the 

 summer months usually at a considerable altitude, as, for example, in the Needle 

 Mountains in Colorado, where it was observed by the writer at an elevation of 

 8000 or 9000 feet. It is a pretty graceful species observed in small parties, 

 now stopping on some dead branch to preen its beautiful plumage, then darting 

 off to course up and down over valley and stream in quest of its prey. It 

 nests in holes in trees and crevices among rocks, making a nest of grasses, feathers, 

 etc., and laying pure white eggs. 



African Saw-winged Swallows. The second subfamily (Psalidoprocnina) 

 comprises, as here restricted, only the Saw-winged Swallows of Africa, their 

 most marked character being the fine serrations on the outer webs of the primaries 

 in the male. They differ from the American Rough-winged Swallows by having 

 longitudinal instead of rounded nostrils, and the prevailing color of the plu- 

 mage black instead of brown. As they do not exhibit any features of particular 

 interest as regards habits, their further consideration may be omitted. 



THE CUCKOO-SHRIKES 



(Family Campephagidce) 



The Cuckoo-Shrikes, or Caterpillar Catchers, as they are oftener and perhaps 

 more appropriately termed, form quite a large group of a dozen genera and up- 

 ward of one hundred and seventy-five species, all natives of the Old World. 

 They are usually placed near, and by some authorities directly with, the Shrikes 

 (Laniida), which they approach rather closely in having a generally stout, 

 moderately notched and hooked bill, but from which they differ uniformly in 

 having the feathers of the lower back and rump with more or less stiffened 

 shafts, "a feature easily ascertained by running the thumb against the plumage 

 nail down." As further characters, it may be mentioned that the nostrils are 



