THE BIRDS OF SOUTH-WEST AND PENINSULAR SIAM. 3 



many times all other collections made in the area. We have also had 

 the advantage from time to time of examining collections made by 

 Mr. Williamson and Mr. Herbert and their collectors, but the number 

 so dealt with has not been large. 



A word is necessary as to the general plan of the paper. 

 From considerations of expense and time it has not been thought 

 necessary or desirable to lis': all the specimens examined of every 

 form included by us. Only those specimens, therefore, some 1500 in 

 number, which were collected on our last expedition from January- 

 April 1919, are listed. These specimens were all carefuhy measured 

 in the flesh, which has not been th3 case with previous collections. 

 The dimensions given are in the same order as the specimens are 

 listed in. 



As our publication is intended to be exhaustive to date, it has 

 be3n thought desirable to give as fully as posslb'e all records of 

 occurrences in the area. Synonymic and taxonomical references are 

 as far as possible omitted. As articles on the area are few in number, 

 but have constantly to be referred to, it has been found to be a saving 

 of space to denote ea^h by a capital, A. B. C, etc , after the first. 



The full references of the whole S3ries are printed at the foot 

 of each page. We have adopted this ingenious p^an from Mr. Stanley 

 Kemp's " Catalogue of the Scientific Serial Publications in the 

 Principal Libraries of Calcutta." (Calcutta, 1918). 



In a certain number of cases where we are convinced that a 

 form tnust occur in the area, though it has not been recorded, we have 

 added it to our list. Such species are distinguished, apart from any 

 context, by having no serial number attached. 



It is hoped that the keys may be of use to those wishful of 

 identifying birds from this region. There are, as a rule, so few 

 species to each genus that it has been found simpler to combine the 

 keys into one for each family : it must be understood that these are 

 strictly artificial and will only work against the species in our list 

 It has been found undesirable to attempt to provide primary keys for 

 the orders and families. These it is hoped will not be found necessary, 

 it being presumed that the majority of persons into whose hands this 



VOL. V, NO. 1, 1921. 



