586 BIRDS OF BRITISH GUIANA. 



singing birds. The remaining Mesomyodian perchers, the songless 

 birds, now call for notice. Of these but three families are repre- 

 sented in Georgetown, two each by one species, while the third, 

 that of the Tyrant Shrikes, comprises many of the commonest of 

 the strictly town perchers." 



Family CORVID.E. 



This family at the time when vol. v. of Sharpe's ' Handlist ' 

 was published in 1909 comprised about forty-two genera and two 

 hundred and seventy-three species. It is almost cosmopolitan 

 in its distribution, being most numerously represented, generically, 

 in Asia, viz., by about nineteen genera, while it is most sparsely 

 represented in South America, where only four genera and about 

 twenty-six species occur. One of the genera and two of the 

 species are represented in British Guiana. 



Genus CYANOCORAX Boie. 

 Gyanocorax Boie, Isis, 182G, p. 975. Type C. chrysops (Vieill.). 



Fig. 214. — Cyanocorax cayanus. 



This genus is distinguished chiefly bj- the bristle-like foatliers 

 on the fore-part of the head. The bill is proportionately short 

 and stout, and the up{)er mandible is slightly notched at the tip. 

 The wing is rounded, the fourth, fifth, sixth, and seventh primaries 

 longest and equal, the third about equal to the ninth, the second 

 nearlv three-fourths the length of the third, and the first about 



