USE OF THE KEYS. 



A key is a short cut used to approximate identification without reading 

 a great number of descriptions. The keys given here differ in no essential 

 particular from those to be found in other systematic works on ornithology, 

 but for the benefit of the beginner their use may be briefly explained. 



Having in hand an unknown bird begin with the key to the Orders 

 (p. 7), reading first the line beginning a^ ; if the specimen has the 

 characters given after a^ then the bird belongs to the Order Pelecani- 

 fprmes and another key is to be used which will be found under that 

 order, (p. 200). If the characters on the line after a^ are not found in 

 the specimen, then those given on the line a- are to be examined and these 

 the specimen must have, if no mistake has been made. The next choice is 

 between 6^ and b- and so on until characters are found which agree with 

 those of the specimen and at the same time lead to a word at the right 

 printed in heavy face type; this is the name of the order to which the 

 specimen belongs. 



Havipg deteniiiued the order turn to the page where the order begins 

 and use the key there which leads to the suborders or to the families, then 

 find and use the keys to genera and species. 



To illustrate the use of keys with a concrete example,. suppose that we 

 have a specimen of the common spoon-billed duck or shoveler, but know 

 nothing of its affinities. Beginning with the key to orders we find : 



'•a\ Hind toe connected by a web to the inner toe." As this does not 

 agree with our specimen we try : 

 ''a^. Hind toe not connected by a web to the inner toe." Yes. 



''b\ Nostrils tubular." No. 



"b-. Nostrils not tubular." Yes. 



"c\ Cutting edges of bill more or less distinctly fringed or serrated, 

 tip of bill rounded Anseriformes." 



Yes, and our bird belongs in the order Anseriformes. By a similar 

 procedure we find that our duck belongs in the subfamily Anatinw 

 (p. 185) and in the key to genera (p. IS?) wo find : 



"a\ Bill not spatulate." 



"a-. Bill flattened, and spatulate Spatula." 



As our duck has a flattened, spatulate bill we turn to the genus Spatula 

 (]). 196) and as there is but one Pliilippine species in this genus we know 

 that our bird is — 



Spatula clypeata (Linnseiis). 



SHOVELER. 



