576 Mr. O. Tliomas on 



lil. — Notes on Bais of the Genus Coleiira. 

 By Oldfield Thomas. 



(Published by permission of the Trustees of the British Museum.) 



A STUDY of the British Museum collection of thtj genus 

 Coleura, amounting to nearly sixty specimens from more than 

 a dozen localities, shows that on the mainland of Africa there 

 are two species: a north-eastern, inhabiting Suakin, Aden, 

 Somaliland, and the Upper Nile ; and a southern, which 

 ranges from the Congo to the Zambezi. The former is sepa- 

 rable into two colour-races. 



Then in the Seychelles there are two forms, both distin- 

 guished from those on the mainLmd by their proportionally 

 longer wings. 



The genus may thus be arranged as follows : — 



A. Wings shorter. Forearm not or little more 



than three times as long as the sliull- 



length *. 



a. Larger. Forearm 49-52 mm. ; skull 16-0 



and upwards ; maxillary tooth-row 7'2 



and upwards. (Ubangui, Angola, Tette.) 1. C. afra, Pet. 



h. Smaller. Forearm 45-48 mm. ; skull less 



than 16; maxillary tooth-row 6"7-7'l . 2. C. gaUarum, sp. n. 

 a'. Hairs nearly unieolor, wood-brown. 



(Suakin, Aden, Somali.) '2 a. C. g. yallarum. 



h' . Hairs bicolor, sepia terminally, white 



basally. (Upper Nile.) 26. C g. nilosa, subsp. n. 



B. "Wings longer. Forearm more than Sg times 



skull-length, 52 mm. and upwards. 



a. Larger. Forearm 55-57 mm. ; skull 15'2; 



maxillary tooth-row 7"0. (Seychelles, 



probably Mah6 Island.) 3. C segchellensis, Pet. 



b. Smaller. Forearm 52-54 mm. ; skull 



14-4-14-7 ; tooth-row 6-5-6-7. (Sil- 

 houette Island, Seychelles.) 4. C. silhouett<e, sp. n. 



It may be noted that the Seychelles species have usually a 

 median septal ridge in the basial pit, and the mainland species 

 not, but there are a great many individual exceptions to this 

 rule. The ridge is always more strongly marked in young 

 specimens than iu old ones. 



I fail to find any specific value in the characters used by 



* From condyle to front of canine. 



