Mr. 11. F. Tomes on the species of Lasiurus. 225 



drawn from the membrane, in which a median furrow is left in its 

 stead, from the inspection of which it may be inferred that the tail 

 occupied the whole length of the membrane (as in the other species 

 of this group). 



The upper surface of the interfemoral membrane has some hairs 

 on its base, as in many species of the genus Vespertilio ; and its 

 under surface bears some transverse lines of small follicles. 



The general colour of the fur is huffy-chestnut, glossy above, and 

 paler beneath. 



in. lin. 



Length of the body 2 4 (English). 



Interfemoral membrane along its central line. . 1 9 



Fore-arm 1 7 



Tibia 9 



I now give a description of a specimen evidently of this species 

 collected at Ega, on the Amazon, by Mr. Bates, and labelled by him 

 " houses, Ega." As it appears to be in a better state of preservation 

 than the two obtained from the same place by M. Castelnau, I am 

 able, besides confirming the accuracy of his description, to give a 

 more detailed scale of dimensions than he has given. 



It is desirable to note, that this specimen, although probably full- 

 grown, yet exhibits some slight indications of non-maturity. 



The muzzle is a little longer relatively than in the species I have 

 before described, and is about as much pointed as in L. novebora- 

 censis. The end of the nose is small ; the nostrils somewhat tubular, 

 with a distinct notch between them. 



The ears are triangular-round, and somewhat more pointed than 

 those of any other species here described. The tragus is similarly 

 formed to that part in L. pruinosus. 



The wing-membranes barely extend to the base of the toes, and 

 the extreme tip of the tail is exserted. 



The fur of the forehead does not approach so nearly to the nose 

 in this species as in the others of the group. 



The basal half of the superior surface of the interfemoral mem- 

 brane is hairy, but the hair does not reach laterally over the tibia. 

 Beneath, it is sparingly hairy at the root of the tail only. The 

 membranes of the wings contiguous to the body, both above and 

 below, are hairy, more especially on their under surface, where the 

 hair reaches to the elbow, but does not follow the fore- arm. 



On all the upper parts the fur is yellowish-buff, the hairs slightly 

 tipped with brownish, and on the under parts uniform yellowish-buff. 



Membranes of the wings darkish brown, the interfemoral mem- 

 brane being paler and marked with about twenty transverse dotted 

 lines. 



in. lin. 

 Length of the head and body, about , . 2 



of the tail 1 7 



of the head 8 



of the ears 3|- 



Ann. ^ Mag. N.Hist. Ser. 2. Vol. xx. 15 



