Only one specimen of this large molossid (from Volcán de Chinandega--J. A. Allen, 1908:670) has been reported from Nicaragua. All of our specimens are from the northern or northwestern part of the country. Many were shot in early evening as they followed a straight, direct flight pattern (presumably from day-roosts toward foraging or watering areas); the series from Potosí was netted over a small stream as described in the account of _Noctilio leporinus_. We confidently refer our material to the species currently known as _ater_, although assignment to the subspecies nigricans is tentative.
Of 21 females autopsied in the first week of March on the Cosigüina Peninsula, seven were pregnant, each with a single embryo (7-22 mm in crown-rump length, average 16.7). Ten males taken at the same time had an average testicular length of 5.7 (2-7) mm, whereas the testes of a male obtained on 9 March at San Antonio measured 8 mm. None of five females obtained in late July in Nueva Segovia evidenced reproductive activity, nor did two of three females taken in July and one taken in August from Chinandega; the fourth Chinandegan female, taken on 17 July, carried an embryo that was 36 mm in length. Two males from southern Chinandega (mid-July) had testes 7 and 4 mm long.
Representative measurements of 10 specimens of each sex from Nicaragua are given in Table 4.
_Specimens._--_Chinandega_: Potosí, 5 m, 1; Hda. San Isidro, 10 km S Chinandega, 20 m, 1 (USNM). _Boaco_: Santa Rosa, 17 km N, 15 km E Boaco, 300 m, 7. _Managua_: 3 mi SW Managua, 8. _Rivas_: Rivas, 60 m, 4.
This small free-tailed species has been reported from Nicaragua by Felten (1957:14), who listed two females from Corinto. Our records indicate that it is widely distributed, but of localized occurrence. Specimens from Potosí and Santa Rosa were captured in mist nets over streams (as described in the accounts of _Noctilio leporinus_ and _Myotis elegans_, respectively). The specimen from Hda. San Isidro was shot in flight, whereas those from Rivas were captured in a daytime retreat in a deep crevice in a concrete school building. We have no precise knowledge of the conditions under which bats from 3 mi SW Managua were obtained but suspect they were taken from a building.