THRESKIORNIS. 
Only a brief diagnosis is there given, which would cover most of the species 
referable to the group. In 1802, however, Daudin named the Ibis-like birds 
described in Buffon’s Historie Naturelle, according to the Lacepedean genera, 
and under the genus-name Ihis included fourteen species. Only two of these 
had been known by the vernacular Ibis, and one of these was, moreover, the 
Tantalus Ihis of Linne. Consequently this species, by the principle of tau- 
tonymy, must be regarded as the type of Ibis Lacepede or Daudin. This 
use was endorsed by lUiger in 1811, but Cuvier in 1816 utilised Ibis for the 
species Ibis cethiopica (Latham), considering that was the true Ibis of the 
ancients. These two species differ so much that they are placed in different 
families, and the family known as Ihididoe must now be called Plegadidce. 
The name to be used for Ibis Auctorum, not Ibis Lacepede or Daudin, is 
Threskiornis Gray, introduced with T. cethiopicus (Lath.) designated as type. 
Egatheus Billberg 1828, was introduced as an absolute synonym of Ibis 
Lacepede — simply as a classical substitute for that generic name. It is 
therefore untenable for any other group, and cannot be used for the 
T. falcinellus Linne birds. 
The birds commonly known as Ibises form a well-differentiated group, 
closely allied in structural characters to the Spoonbffls, from which they 
differ in the shape of the bill. The head and neck is bare of feathers, and 
ornamental plumes are generally developed on the breast and wings. 
A 
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