102 PROCEEDINGS OF THE ACADEMY OP 



plish in the destruction of noxious insects and small animals 

 should commend them to public favor. Besides subsisting upon 

 insects, small animals, carrion, grass, and fruits, I have in two 

 instances observed individuals, which I took to be males, imitating 

 the habit of their nearest kin, the fish crow, by plying the trade of 

 fishers. There is no doubt that in the case of Corvus ossifragus, 

 this habit was similarly acquired b}'^ a few birds of more sagacity 

 than others. The period of incubation I have not satisfactorily 

 determined, but am confident that it cannot exceed eighteen days. 



Corvus ossifragus. 



This species, though assigned to the South Atlantic and Gulf 

 States by Dr. Coues in his Key to North American Birds, has 

 been observed by the writer during the past four years to breed 

 within the rural districts of Philadelphia. Although designated 

 by the same great authoritj^ as a maritime species, yet it should 

 be considered only partially so. It has been observed in company 

 with its near relative the common crow, and commences buildino- 

 at the same period. Its nest, unlike that of the crow, is constructed 

 upon a willow, by the side of a watercourse, where it can ply its 

 piscine trade without being molested. Externally, it consists of 

 a few rude sticks as a sort of foundation, upon wliich a neat and 

 comfortable superstructure, composed of the inner fibrous parts 

 of the red cedar, is placed, loosel}^ arranged, the whole present- 

 ing a neater and more fastidious appearance than that of the 

 common crow. The eggs are four in number. The ground-color 

 is a light blue marked with a few dots and blotches of umber- 

 brown on the small end, which are more or less confluent on the 

 large one, obscuring to a considerable extent the background. In 

 size they are but little superior to the eggs of the purple grakle, 

 being about 1.40 in. in length, and .89 in width. In configuration 

 they bear a very close resemblance to those of the great crested Fly 

 Catcher, being almost perfectly oval. There is a marked contrast 

 between the eggs of ossifragus and Americanus in size, shape, 

 and markings, sufficiently striking to convince one of the distinct- 

 ness of the two species, even though other details should be 

 wanting. I have never met with more than one brood in a season. 

 It is like its cousin in some points of character, but minus its 

 thievish propensities. A fisher by trade, it holds all other occupa- 

 tions at a discount. It is fond of its young, but has not the 



