f _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 Cosigueina
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_: Potosi, 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 Potosi 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.

Females in our series were reproductively active at all times for which
we have information--early March through mid-July--as follows: a female
from Potosi (6 March) carried an embryo that measured 5 mm (crown-rump
length) as did one from Santa Rosa (21 March, 17 mm in length); two of
three females taken 3 mi SW Managua on 28 March were pregnant (embryos
13 and 15 mm), whereas each of two collected there on 3 May were gravid
(embryos 27 and 30 mm); one female from Rivas (25 June) carried an
embryo (30 mm) and another was lactating and accompanied by a small
(forear