Selected measurements of the male are: total length, 92 mm; length of tail, 31 mm; length of hind foot, 10 mm; length of ear, 15 mm; length of forearm, 39.2 mm; weight, 10.3 gms; greatest length of skull, 17.2 mm; zygomatic breadth, 10.6 mm; postorbital constriction, 4.0 mm; breadth of braincase, 8.6 mm; length of maxillary toothrow, 6.5 mm. Eumops auripendulus (Shaw, 1800) A broken skull (USNM 339917) of a female of this species from Hda. Mecatepe [2 km N, 11.5 km E Nandaime, _ca._ 40 m], Granada, represents the only known specimen of the genus _Eumops_ from Nicaragua. This bat was obtained by M. K. Clark on 25 August 1964, but the conditions under which it was captured are not known. Available cranial measurements are: zygomatic breadth, 12.6 mm; breadth of braincase, 10.7 mm; postorbital breadth, 4.3 mm; rostral breadth, 7.4 mm; length of maxillary toothrow, 9.1 mm; length of mandibular c-m3, 10.0 mm. Molossus ater nigricans Miller, 1902 _Specimens._--_Chinandega_: Potosí, 5 m, 21; 4.5 km N Cosigüina, 15 m, 2; El Paraíso, 1 km N Cosigüina, 20 m, 17; Hda. Bellavista, 720 m, Volcán Casita, 4; Hda. San Isidro, 10 km S Chinandega, 20 m, 2; San Antonio, 35 m, 2. _Nueva Segovia_: Corozo, 15 km NNE Jalapa, 660 m, 1; 3.5 km S, 2 km W Jalapa, 660 m, 4. 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. Molossus molossus aztecus Saussure, 1860 _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.