2 PROCEEDINGS OF THE NATIONAL MUSEUM vol.75 



At the time Doctor Abbott was active in this region, he was unable 

 to get permission from the Dutch authorities to visit Siberut and 

 Sipora, two islands of fair size lying north of the Pagi Islands, and 

 with them constituting the Mentawi Group. 



When, in the autumn of 1924, Mr. Kloss and a party from the 

 Raffles Museum, Singapore, visited Siberut and Sipora to make a 

 general natural history survey, Doctor Abbott contributed funds in , 

 aid of the enterprise, in return for which support the United States i 

 National Museum was to receive a set of the duplicates. 



After writing an account of the birds, in conjunction with Mr. 

 F. N. Chasen,^ Mr. Kloss, the Director of the Raffles Museuni, for- 

 warded the whole collection to Washington, with the exception of ' 

 certain specimens which he took to London for further study, and 

 requested the writer to prepare a review of the collection after mak- 

 ing comparisons with related material in Doctor Abbott's collections i 

 from neighboring islands. 



A report upon the avifauna of the whole chain of islands off the 

 west coast of Sumatra would be welcome, but the writer does not 

 wish to anticipate the results of Doctor Oberholser, who has been 

 engaged upon the birds of this general region for so many years. 

 For this reason he has confined himself to the Mentawi Group alone, 

 more particularly to Siberut and Sipora, and has mentioned related 

 forms from other islands only when in his opinion this would lead 

 to a better understanding of the Mentawi birds. 



Chasen and Kloss, in their paper (cited above), named 11 new 

 subspecies from Siberut and Sipora, three of which are not recog- 

 nized in the present paper, but the writer ^ has described three addi- 

 tional ones which are believed to be valid. Two of these are from 

 Siberut and Sipora, the other from Sipora and the Batu Islands. 

 This arrangement leaves 10 forms confined to the two northern i 

 islands, but in the Mentawi Group as a whole there are 32 peculiar 

 forms. 



The islands off the west coast of Sumatra generally are closely 

 related in their avifauna to the mainland and Sumatra, as would 

 naturally be expected, with a few well-differentiated species and 

 many more or less well-marked races. As a rule, the forms from 

 Simalur seem to be more strongly characterized than those from the 

 remainder of the chain, with the possible exception of Engano. 



Messrs. Chasen and Kloss are to be congratulated upon their suc- 

 cessful trip and on their published ornithological results ; their paper 

 has left very little to be supplied here that is additional or new. 



■s Ibis, 1926, pp. 269-306. 



• Proc. Biol. Soc. Wasiiington, vol. 40, 1927. pp. 95, 96. 



