672 



U. S. p. R. R< EXP. AND SUEVETS — ZOOLOGY — GENERAL REPORT. 



lanceolate, and reacliing nearly its lengtli beyond tlie tip of the tail, each feather well defined 

 and the webs not decomposed. 



The body generally in the adult is slaty blue ; the head and neck glossed with bluish purple ; 

 the concealed portions of the feathers, purplish brownish red. There is no trace of white on the 

 throat. The bill in life is said to be ultramarine blue at the base, shaded into black towards 

 the point ; the bare space between it and the eye, as well as the edges of the eyelids, ultra- 

 marine. The iris pale yellow ; the legs, tarsi, and toes, black. 



The young bird is pure white ; the head smooth, and the feathers without the decomposed 

 webs. The scapulars are not elongated. The iris is white ; the bill light blue, blackish at the 

 end ; the skin around the eyes and the base of the bill light yellow ; the legs light green. 



Birds changing show a confused patching of white and blue. 



The young bird in white dress is much like the Garzetia candidissima, but is without any of 

 the plumes or crests of the latter species, and almost always shows here and there a trace of 

 blue, instead of being pure white. The middle toe is much longer. The feet are entirely 

 greenish to the claws (livid black in the dry skin) instead of having the toes yellowish, and the 

 base of the bill is without the abruptly defined yellow portion. 



According to Lichtenstein, "the A. caerulea of Linnaeus has the feathers of neck and occiput 

 and the scapulars well defined and linear ; the bill black ; the legs brown, with yellow toes. 

 Length, 18 inches ; bill, 2.50 ; tarsus, 3. Hab. — Cayenne. The North American A. caerulescens 

 has the same feathers with the fibres loose ; the bill whitish at base ; the legs and toes greenish. 

 Length, 22 inches ; bill, 3 ; tarsi, 4." The species he refers to first is evidently a true Herodias. 



LiH of specimens. 



ARDBTTA, Gray. 



Jlrdtita, Gray, List of Genera, Appendix, 1842, 13. Type Ardm mmuta, L. 

 Ardeola, Bonaparte, Syn. 1828. Type Ardea exilis, L. Not Ardeola, Boie, Isis, 1823. 



Ch. — Bill slender, acute; both mandibles about equally curved. Legs very short; tarsi less than middle toe. Inner toe 

 much longest. Claws long, acute. Tarsi broadly scutellate anteriorly. 



Tail often feathers. Neck short. Body much compressed. Head smooth ; the occipital feathers somewhat lengthened ; the 

 lower neck bare of feathers behind. No plumes. Plumage compact, lustrous ; Uniform above. Sexes differently colored. 



This genus embraces the smallest known species of heron, and has representatives in all 

 quarters of the globe. 



