1917.] Allen, Lang and Chapin, Bats from the Belgian Congo. 407 



represented in the present material. A number of them are based appar- 

 ently on single specimens, sometimes alcoholic, and the descriptions are 

 consequently not entirely satisfactory as an adequate basis for critical 

 comparison. It is not therefore surprising that the present large amount 

 of material should include a considerable number of new forms, some of 

 them of obvious distinctness from any previously recorded, while others 

 seem nearly related to forms described from contiguous countries, with 

 which direct comparison has in most cases been impossible. In such 

 instances it has seemed preferable, in view of the geographical conditions 

 and the apparent discrepancy in characters involved, to give names to such 

 forms than to merge them with forms already described to which they 

 seem not properly referable. Of the 68 forms here recorded, 29 are de- 

 scribed as new. Two superspecific groups are also characterized, one of 

 which (Allomops, p. 470) is closely related to Mops, the other Lophomops, 

 p. 460) to Chcerephon. 



In working up this intensely interesting collection I have been greatly 

 indebted to Mr. Herbert Lang, the leader and organizer of the Expedition, 



Fig. 1. Outline drawings showing how the ear was measured by the collectors. A. Saccolaimus 

 peli (y); B. Eidolon hehum (§). 



and to Mr. James P. Chapin, his able and enthusiastic co-worker during the 

 six years of their continuous, exceptionally successful and intelligent field 

 work in Equatorial Africa for invaluable information regarding the environ- 

 mental conditions and relationships of the localities at which the present 

 material was collected. Their contribution of field notes and illustrations 

 to the present paper. I am sure will be recognized as the most important 

 contribution ever made to the life-history of the Chiroptera of Africa. 

 The text illustrations of the cranial and external characters of certain 

 species are contributed by Mr. Chapin, except those of the skull of Keri- 

 voula cuprosa, which were made by E. S. Christman. The plates are from 

 drawings by Mr. Chapin and from field photographs by Mr. Lang. 



