APRIL, 1914. MAMMALS or NORTHERN PERU OSGOOD 1 1 | I 181 



are larger and wider than in Furipterus and the principal cusps are 

 higher, but the cingulum is so slightly developed as to be visible only 

 upon the closest examination. The lower incisors, canine, and pre- 

 molars are more similar in the two genera than the corresponding upper 

 teeth, but in Amorphochilus there is practically no tendency to the 

 development of cusps from the cingulum. A slight space exists between 

 the inner pair of lower incisors. Lower molars with scarcely any 

 cingulum. Entoconids relatively farther from metaconids; commissure 

 from entoconid to hypoconid higher and stronger, especially in the first 

 lower molar, in which the entoconid is but slightly higher than the 

 commissure, which forms a broad blade. 



The following measurements have been taken: Male, measured in 

 flesh: Total length 86; tail 28; hind foot 7. Female, in alcohol: Total 

 length 83; head and body 54; tail 29; hind foot 6.5; forearm 36; third 

 digit: metacarpal 34.4, ist phalanx 5.2, 2nd phalanx 22.2; fourth digit: 

 metacarpal 31, ist phalanx 6.8, 2nd phalanx 10.5; fifth digit : metacarpal 

 31.2, ist phalanx 10.5, 2nd phalanx 6.7; tibia 18; calcaneum 15.3. 

 Skull: Greatest length 12.1; basal length 11.3; interorbital constriction 

 13.1; zygoma tic width 7.3; mastoid width 6.5; maxillary width at base 

 of M 2 4.8; width between tips of canines 2.5; width of braincase 5.8; 

 depth of braincase including audital bullae 6.7; frontal angle to occiput 

 7.6; upper toothrow, C to back of M 4 4.7; width of M 3 1.3; lower tooth- 

 row including incisors 5.7. 



Myotis nigricans (Wied). 



Six specimens, Moyobamba. 



Although fairly common and widely distributed, vespertilionine 

 bats usually are more difficult to obtain in South America than those 

 of other groups. In almost all cases where we saw them, it was under 

 conditions where shooting was extremely difficult. While staying at 

 "Los Bafios, " near Moyobamba, we discovered the roosting place of 

 some of these small bats in the side of the wall of a house, the only 

 entrance apparent being a crevice in a door jamb. A light net stretched 

 over this crevice early in the evening soon entangled six bats, evidently 

 all that were roosting in that place, for no further captures were made 

 although the net was kept there for several days. Such differences as 

 appear on comparison of these specimens with others from eastern 

 Brazil are not sufficiently marked to warrant any separation at the 

 present time. 



