334 ME. O. THOMAS OX MAMMALS FEOM CENTRAL PERU. [Apr. 18, 



1. Xtctipithecus TBIVIRGATUS. 



rt, h. Ad. ska. 6 $ • Chanchamayo. bl^ldO. 



2. Yesperus Fuscrs, P. de Beauv. 

 a. Ad. al. J . Chanc-hamayo. 



3. Saccoptertx leptcra, Schr. 

 a. J al. Chanchamayo. 



4. Saccopterts bilixeata, Temm. 



a, h. 2 S al. Chanchamayo. 



As Dobson has remarked, these two species of Saccopteryx seem 

 to be merely large and small races of a single form, exactly as in 

 Molossus rufus and M. olscurus. The difference in size, however, is, 

 in the one case as in the other, so great and so constant as to 

 make it convenient to treat them all as distinct species so far as 

 nomenclature is concerned. 



5. Molossus oescurus, G-eoffr. 

 a-e. 5 in al. Central Peru. 



6. jSTTCTEsroMUS KALiNowsKii, sp. u. (Plate XXIX. fig. 10.) 



Size very small, perhaps the smallest of the genus in the general 

 bulk of the body. Lips slightly wrinkled. Ears not conjoined in 

 front, but arising from the same point on the muzzle ; their 

 substance very thin and transparent ; their inner margin evenly 

 but faintly convex, without minute horny points ; tip rounded off, 

 but fairly defined, not lost in the general convexity, as is often the 

 case ; outer margin shghtly convex for its upper, concave for its 

 middle, and convex again for its lower third, but the curves are 

 very slight and open, and there is practically no antitragus at all, 

 the notch marking this lobe behind being almost obsolete ; as a 

 general result the line of the conch runs almost evenly from the 

 tip to the insertion behind the angle of the mouth, a character, I 

 beheve, unique in the genus. 



Keel of ear-conch very much reduced, and forming a mere 

 narrow rim, barely a millimetre broad at its broadest point; its 

 edge not thickened or bent round in any way. Tragus well 

 developed, quadrangular, its upper nearly equal to its inner edge. 



Xo trace of a gular sac, at least in the female. 



Wing-membrane from the ankle. Fur veiy short and close, 

 extending on the upper surface of the wing-membrane onlv as far 

 outwards as a fine draAMi from the middle of the humerus to the 

 middle of the femur ; a few minute scattered hairs behind the 

 forearm. 



Colour pale fawn-grey, rather paler below than above ; wing- 

 membranes black, edged posteriorly ^\•ith white. Membrane of 

 ears whitish. 



Teeth too much worn down in the type for proper description ; 



