1 
Genus— THE E SKI ORNIS. 
Threskiornis Gray, List Genera Birds, App., 
p. 13, 1842 . . . . . . . . . . Type Threskiornis cethiopicus. 
Also spelt Thereschiornia Brehm, Naumaiinia 1855, p. 290. . 
Ibis (Cuvier), Cat. Birds Brit. Mus., Vol. XXVI., p. 4, 1896. 
(Not Ibis LacepMe 1799.) 
PLEGADEsrE birds with long, curved, slender bill, long wings, long legs and 
feet, and long tail. 
The bill is very long, comparatively slender, and strongly decurved : a 
long, shallow but distinct groove extends along the sides of the upper mandible 
for its whole length : the nostrils are linear and placed in this groove at its base ; 
the head is denuded of feathers ; there is a shallow depression on the sides of 
the lower mandible for about one-third its length. The wing is long and 
somewhat rounded, only about twice the length of the culmen ; the third 
primary is longest, the second and fourth a little shorter and sub equal, the 
first less than the fourth ; the inner secondaries are longer than the primaries, 
and are elongated as ornaments, with the webs somewhat disconnected. 
The tail is rounded, composed of twelve feathers and about one-third the 
length of the wing. The legs are long : the metatarsus reticulate through- 
out, and a long, exposed tibia. The toes are long, with a short web 
between, and a long hind toe is present. 
The present genus has been recently known under the name Ibis, following 
the Catalogue of the Birds in the British Museum, Vol. XX VT., 1896. In 
my “ Reference List ” I used that generic name, referring it to Lacepede 1799 
as the earliest introduction. For the genus here known as Plegadis Kaup 
1829, I used Egatheus of Billberg 1828. Towards the end of 1912, Dr. C. W. 
Richmond wrote me, pointing out the erroneous use of the latter name, and 
probably also of the former. I therefore investigated the matter, as litera- 
ture unavailable to Dr. Richmond in America was at my command here. 
I detailed my results in the Auk^ Vol. XXX., pp. 92-95, 1913, but as 
many of my readers will not have that journal at hand for reference, I wiU 
summarise my conclusions here. 
The generic name Ibis was first proposed by Lacepede in a small brochure 
entitled Tableau Oiseaux, and published in 1799. This Table was reprinted in 
the Me^n. Inst. Nat. Hist., Paris, 1801, from which it has been commonly quoted. 
378 
