24 



Birds of Pennsylvania. 



eggs are laid. The eggs are pale-blue^md larger than those of our 

 common pigeon. 



Food. 



This species feeds much more frequently on insects than other of 

 the Herons that reside with us. Nuttall writes of the Green Heron 

 in the following language : " He is also particularly attracted by ar- 

 tificial ponds for fish, not refraining even to visit gardens and domes- 

 tic premises which any prospect of fare may offer. He is, at the same 

 time, perhaps as much in quest of the natural enemy of the fish, the 

 frog, as of the legitimate tenants of the pond. These bold and intru- 

 sive visits are commonly made early in the morning, or towards twi- 

 light, and he not unfrequently, when pressed by hunger, or after ill- 

 success, turns out to hunt his fare by day as well as dusk, and, at such 

 times, collects various larvae, particularly those of the dragon-fly, with 

 grasshoppers and difi"erent kinds of insects. At other times he preys 

 upon small fish, crabs and frogs, for which he often lies patiently in 

 wait till they reappear from their hiding places in the water or mud, 

 and on being transfixed and caught, which is eff'ected wiih great dex- 

 terity, they are commonly beaten to death, if large, and afterwards 

 swallowed at leisure." 



* Four young birds taken from the nest. 



Genus NYCTICORAX. Stephens. 

 202. Nycticorax nycticorax nsevius (Bodd). 



Black-cro\nied Night Heron. 



Description. (Plate 6.) 



Head above and middle of back steel-green ; wings and tail ashy-blue ; under 

 parts, forehead, and long occipital featliers white ; sides tinged with lilac. 



Bill very thick at the base, and tapering all the way to the tip. Culmen nearly 

 straight for half its length, then considerably curved ; lower outline of bill nearly 



