336 MR. o. THOMLiS OS iiAMiLiLS TEOM ce>t:e.vl PEur. [Apr. 185 



10. Autibeus' glattcus, sp. n. (Plate XXIX. figs. 7-9.) 

 a. 5 al. Chanchamayo. Ty2^e. 



Dentition as in the restricted subgenus Artibens, o£ which the 

 only known member is the large " A. perspicillatus,'^ whether that 

 is or is not subdivided into four or five local " species." Size as in 

 the little A. (Dermanv.ra) cinereus. 



Anterior edge of nose-leaf free, its sides without extra lobes, its 

 upright portion rather narrow and elongated. Ears rather short, 

 their inner edge and tip broadly rounded, their outer edge with 

 two slight concavities separated by a convexity. "Wings to the 

 end of the metatarsus. Interfemoral membrane emarginate to a 

 point rather above the level of the middle of the tibia. 



Fur above extending on to the proximal half of the foramen and 

 base of antebrachial membrane, and there is a patch on the meta- 

 tarsus of the thumb. The wings are covered as far as a line 

 extending from the elbow to the knee, the interfemoral is thinly 

 clothed on its basal half, and the legs are covered with fur right 

 down to the cla\^s. Below there is a sparse covering on the 

 membrane near the body and on the base of the forearm, but the 

 interfemoral membrane is almost naked. 



Colour uniform cinereous grey, the louer surface scarcely lighter 

 than the upper. Two faint whitish supraorbital streaks just dis- 

 tinguishable. 



Slcull in its general outline almost as elongated as that of A. 

 hilohaius, and sharing with that species in the less abrupt rise of 

 the brain-case above the level of the muzzle ; but while in A. hilo- 

 hatus it is the muzzle that is raised, in A. r/laucus it is the brain- 

 case which is depressed, so that there is no really close resemblance 

 between the two. General palatal outline broader and shorter 

 than in A. hilohatus, but not so much so as in A. cinereus and 

 quadrivittatus. 



Teeth. Upper inner incisors broad, vertical, spatulate, bicuspid, 

 the inner cusps shghtly longer than the outer. Outer incisors 

 about half the height of the inner. Upper canines and premolars 

 rather short and thick. No trace of m^, although m^ has a slight 

 and inconspicuous concavity in its posterior edge. Lower incisors 

 equal, bicuspid ; lower canine and posterior premolar attaining the 

 same altitude ; iu^ of about the same horizontal length as m^ ; m^ 

 rounded, minute, its size in cross section only about equal to that 

 of one of the lower incisors. 



Dimensions of the type, a shghtly immature female^ in spirit; — 

 Forearm 4.3 mm. ; head and body 51 ; ear from notch lo'S ; nose- 

 leaf, length 11*7, breadth of horizontal part 6"1, of upright part 4 ; 

 length of thumb 9-3; tibia 15-2; foot 10; calcar 4-1; depth of 

 interfemoral in centre 7. 



^ There appears to be no reason why this name should not be retained as 

 originally formed by Leach, or why Agassiz's derivation of it from dpri and jiau 

 should be rejected ; Winge's proposed amendment of it to Arfohiu!> (' Bats of 

 Lagoa Santa— E Mus. Lundii,' p. 38, 1892) is therefore unnecessary. 



* Teeth all up and in use, but epiphyses of limb-bones not fully united. 



