150 BRITISH GUYANA BIRDS EGGS. 



12. Arde a coerulea, L. 

 Blue Gaulding. 



One egg (N°. 12). 



13. A r d e a tricolor, Müll. 



vln/ea leucogaster, Gni. (Schleg. Mus. P.-B. Ardeae, p. 9). 



Grey Gaulding. 



One egg (N°. 13). 



These three herons build a nest like the nest of Nyctico- 

 rax violaceus (L.) mentioned sub N°. 15, in the same loca- 

 lity, at the same time, and often on the same tree. Once 

 in a way isolated nests are found in the low bushes that 

 fringe the creeks. 



They lay two or three eggs. 



The egg is light green, but varies much in shade as well 

 as in shape and size, the length being about 42 mm. and 

 the breadth about 30 mm. : some eggs are almost round. It 

 is not possible to identify the egg by inspection alone : their 

 eggs and the egg of N°. 14 can be distinguished by size only. 



14. Butorides g riseus (Bodd.). 

 Ardea scapularis , 111. (Schleg. Mus. P.-B. Ardeae, p. 42). 

 Ardea cyanura , Vieill. Encycl. Method, p. 1120. 



Shypook. 



The nest is flat and made of sticks and grass in low 

 bushes and tall water plants about unused canals and on 

 the margin of quiet creeks. 



They lay three or four eggs. 



The egg — 37 mm. by 29 mm. — is light green. 



They build in colonies , and hatch from May to July. — 

 One egg (N°. 9). 



1 5. N y ctic o r a x violaceus (L.). 

 Quaak. 



The nest of this bird is similar to the nest of Butori- 

 des griseus , only larger , and they build in colonies on the 



Notes from the Leyden Museum, "Vol. XI. 



