696 Mr. M. J. Nicoll on the Birds collected and 



but until I can examine more examples it is impossible to 

 separate it on the strength of one immature specimen. 



Demiegretta sacra (Gm.). 



Demiegretta gularis Ridgway, Proc. U.S. Nat. Mus. xviii. 

 p. 530 (Aldabra). 



Demiegretta sacra Sharpe, Cat. B. B. M. xxvi. p. 136. 



Adult male (blue phase) ; adult male (white phase). 



Bare skin of face and iris yellow ; bill black : tarsi black, 

 feet yellow. 



I saw several of these beautiful Reef-Herons at Assump- 

 tion. They were quite tame, but I do not know whether 

 they breed there. 



Butorides crawfordt. (Plate XXI.) 



Butorides crawfordt Nicoll, Bull. B. O. C. xvi. p. 105. 



I shot one specimen of this new species (an adult male) as 

 we were rowing ashore the first day. I afterwards saw 

 several other examples, but, unlike members of this genus 

 generally, they were extremely shy and would not allow of 

 approach within gunshot. 



This species is very distinct from B. atricapilla ; the crown 

 of the head is distinctly bluish instead of green ; the wing- 

 coverts are edged with white, and the whole of the lower 

 surface, including the under-wing-coverts, is pure milky 

 white instead of dusky grey as in B. atricapilla. The neck 

 is entirely unspotted with red, and a single line of faint dusky 

 spots extends from the chin down the centre of the throat. 

 The bill is also shorter, thicker, and slightly decurved. 



Dr. Abbott did not meet with a Butorides on Assumption, 

 but it seems from Ridgway's account (Proc. U.S. Nat. Mus. 

 xviii.) that he did not make a long stay on the island. 



Gygis alba (Sparrm.). 



Gygis alba Ridgway, Proc. U.S. Nat. Mus. xviii. p. 520. 

 Gygis Candida Saunders, Cat. B. B. M. xxv. p. 149. 

 One adult male. Bill hyacinth-blue at base, rest black; 

 iris black ; tarsi and toes pale blue, webs milky white. 



I saw several of these White Terns on Assumption, but 



