BRITISH GUYANA BIRDS EGGS. 147 



5. Cassicus persicus (L.). 

 Sawacco, Mocking Bird, Oriole. 



They build in colonies and make a hanging nest of grass , 

 tendrils of crisping plants, and strips torn from the leaves 

 of the cocoanut palm , from the end of the branches of 

 trees or low bushes, if the latter hang over water. They keep 

 on the lea side of the tree. The distance of the nest from 

 the ground depends a great deal oo the locality , and is 

 from eight feet on low bushes , to fifty or sixty feet on tall 

 forest trees. 



The nests are about eighteen inches long and four 

 inches in diameter and are very uniform in shape and size. 

 The shape is like a bag closed in at the top , with the en- 

 trance in the side near the attachment to the branch. The 

 sides round the entrance project a little, forming a funnel. 

 The bird builds from the inside and finishes the nest in 

 from eight to ten days. 



They lay two, rarely three eggs. 



The egg — 30 mm. by 20 mm. — is white with a 

 slight shade of blue , and may have a few light brown and 

 violet spots at the large end , or a great many similar spots 

 distributed over the entire surface. 



They hatch from January to June, and if the year has 

 been dry build again in October and November. If the 

 first months of the year are very wet , their building ope- 

 rations are delayed. — Two eggs (N°. 17). 



6. Cassicus af 'finis , Sw. 



They build in colonies and make a nest like the nest 

 of Cassicus persicus , on the same tree sometimes , but never 

 on the same branch. 



They lay two eggs. 



The egg — 30 mm. by 21 mm. — is bluish white, 

 thickly covered with light purple spots, more numerous 

 at the large end , with a few light brown spots here and 

 there. 



Notes from the Leyden Museum, Vol. XI. 



