On Bats of the Genus Promops. 61 



palatal foramina 7*5 ; width of posterior nares 4 ; upper 

 molar series (crowns) 12*5. 



Another, older, female skull has an approximate condylo- 

 basal length of 69 mm., with intertemporal diameter 12 mm. 



Hob. Chantabun, S. Siam. 



Type. Adult female. B.M. no. 7. 1. 1. 163. Collected by 

 M. Henri Mouhot. Tomes Collection. Three adult and 

 two young specimens, all collected by Mouhot. 



This species is distinguishable from its allies, the other 

 members of the pruinosus group, by its thin fur, browner 

 colour, and the height and convexity of its brain-case. 



VIII. — On Bats of the Genus Promops. 

 By Oldfield Thomas. 



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



The genus Promops, as restricted by Miller *, contained at 

 the time the latter wrote only two species — P. nasutus, Spix, 

 from the Rio Sao Francisco, Brazil, and P. foster i, Thos., 

 from Paraguay. When describing P. fosteri, I took as 

 representing P. nasutus the large species so named by 

 Dobson, but Mr. Miller has suggested to me that it is the 

 Paraguayan bat which is the real nasutus, and that I should 

 have described the larger form as new. 



Since that time a certain amount of additional material has 

 come into the Museum, and I have now examined it with a 

 view to clearing up the confusion on the subject. 



The most important specimen is one collected by A. Robert 

 in 1903 at Lamarao, Bahia, a locality so near the Rio Sfio 

 Francisco that the specimen, which agrees sufficiently closely 

 with Peters's description and figure of Spix's type, may be 

 taken as representing the real Promops nasutus. 



Peters's measurements of the skull are a little inconsistent 

 inter se, so that some must be erroneous, but the majority of 

 them, and the excellent figure, agree nearly with Mr. Robert's 

 specimen, which is, as Mr. Miller suggested, a comparatively 

 small form, widely different from the Molossus nasutus of 

 Dobson, but yet not quite the same as P. foster i. 



A study of the whole series indicates that six forms of 

 Proviops may be distinguished, two large ones from opposite 

 ends of the range of the genus and four small ones from 

 Brazil, Paraguay, and Argentina. They are mostly dis- 

 tinguished by size, so that, taking an exact measurement 



* " Families and Genera of Bats," U.S. Nat. Mua. Bulletin 57, p. 259 

 (1907). 



