Mammals from British Guiana. 141 
8. Molossus maurus, sp. un. 
a. 3S skin. December 11. Alt. 240 feet. Type. 
. 2 1-1 
Incisors 3. Premolars =. Other characters much as in 
M. (Promops) abrasus. 
General appearance very much as in M&M. abrasus, the 
colour, texture of fur, and structure of ears being all about 
as in that species. Colour throughout dark chocolate-brown ; 
hairs of back about 6 mm. in length. Lars of medium size, 
not united, their inner bases close together; no trace of the 
characteristic muzzle-ridge of W. rufus; inner lobe thickened, 
flattened externally ; outer and inner edges straight, at about 
right angles to each other, the tip broadly rounded off; a 
small convexity at the outer base just before the deep anti- 
tragal notch; antitragus long and deep, so that it may be 
described as triangular with a rounded upper angle, quite 
unlike the circular antitragus of MW. rufus; tragus small and 
narrow. 
Gular sac distinct, at leastin male. Limbs and membranes 
apparently naked throughout, except just at the base of the 
tail and femora. 
Skull in its general shape, although smaller, remarkably 
like that of JZ. abrasus, the shape and height of the muzzle, 
the development of the crests, and the proportions of the 
brain-case all as in that species. Ante- and supra-orbital 
edges rounded; mesial crest low, commencing just in front 
of the most constricted part of the skull and running back to 
the occiput. Palate ending nearly a millimetre behind the 
level of the last molar. Angles of lower jaw slender, not 
abnormally expanded laterally. 
Teeth in shape and proportion quite like those of IZ. abrasus, 
but there is no trace of the minute upper premolar. 
Dimensions of the type :— 
Forearm 53 millim. 
Head and body (in flesh) 64; tail (in flesh) 51; ear 19; 
antitragus 6°1 x 4°5; third finger, metacarpal 53, first phalanx 
24:5, second phalanx 22°5; top of knee to tip of hind 
claw 29. 
Type. B. M. no. 1. 6. 4. 34. 
This distinct bat falls into the group that has been called 
Myopterus, and by its size, dentition, and elongated antitragus 
may be readily separated from any known species. 
The original Myopterus Daubentont, whose skull-dimensions, 
as given by Peters *, agree closely with those of MZ. maurus, 
* MB. Ak. Berl. 1869, p. 402. 
Ann. & Mag. N. Hist. Ser. 7. Vol. viii. 11 
