| Number of specimens averaged or catalogue number, and sex | Length of forearm | Greatest length of skull | Condylobasal length | Zygomatic breadth | Breadth of braincase | Length of maxillary toothrow | Breadth across upper canines |
| Molossus ater nigricans, Departamento de Chinandega, Nicaragua | |||||||
| Average 10 (♂) | 49.5 | 23.2 | 20.2 | 14.3 | 11.0 | 8.2 | 6.1 |
| Minimum | 48.2 | 22.8 | 19.9 | 14.1 | 10.5 | 8.0 | 6.0 |
| Maximum | 50.7 | 23.5 | 20.5 | 14.9 | 11.2 | 8.3 | 6.3 |
| Average 10 (♀) | 49.0 | 22.0 | 19.2 | 13.6 | 10.7 | 7.8 | 5.8 |
| Minimum | 47.1 | 21.5 | 18.8 | 13.3 | 10.5 | 7.6 | 5.6 |
| Maximum | 51.2 | 22.5 | 20.0 | 14.1 | 11.0 | 8.2 | 6.1 |
| Molossus pretiosus pretiosus, Departamento de Boaco, Nicaragua | |||||||
| Average 8 (♂) | 45.1 | 21.7 | 18.8 | 13.4 | 10.6 | 7.6 | 5.9 |
| Minimum | 44.1 | 21.0 | 18.3 | 13.1 | 10.2 | 7.4 | 5.6 |
| Maximum | 46.1 | 22.2 | 19.1 | 13.7 | 10.9 | 7.9 | 6.1 |
| Average 23 (♀) | 43.6 | 20.2 | 17.7 | 12.5 | 10.1 | 7.3 | 5.2 |
| Minimum | 41.0 | 19.5 | 17.2 | 12.2 | 9.5 | 7.1 | 5.0 |
| Maximum | 44.8 | 20.7 | 18.2 | 13.1 | 10.4 | 7.6 | 5.6 |
| 6 mi SW Managua, Nicaragua | |||||||
| KU 70135, ♂ | 44.8 | 21.7 | 18.6 | 13.0 | 10.2 | 7.7 | 5.8 |
| KU 70137, ♂ | 45.1 | 21.6 | 19.0 | 13.2 | 10.7 | 7.7 | 5.8 |
| KU 70136, ♀ | 43.5 | 19.9 | 17.8 | 12.7 | 10.3 | 7.5 | 5.5 |
| 3 km N, 4 km W Diriamba, Nicaragua | |||||||
| Average 7 (♂) | 44.8 | 21.2 | 18.5 | 13.0 | 10.5 | 7.4 | 5.5 |
| Minimum | 43.8 | 20.7 | 18.3 | 12.7 | 10.2 | 7.2 | 5.4 |
| Maximum | 45.7 | 21.3 | 18.8 | 13.3 | 10.9 | 7.6 | 5.5 |
| Average 9 (♀) | 44.0 | 20.7 | 18.0 | 12.6 | 10.2 | 7.3 | 5.3 |
| Minimum | 42.0 | 20.0 | 17.4 | 12.0 | 10.0 | 7.0 | 5.0 |
| Maximum | 45.5 | 21.2 | 18.6 | 13.0 | 10.6 | 7.5 | 5.5 |
| Molossus sinaloae sinaloae, El Recreo, Nicaragua | |||||||
| Average 4 (♂) | 47.6 | 21.2 | 18.6 | 12.3 | 9.8 | 7.7 | 5.4 |
| Minimum | 46.7 | 20.7 | 18.3 | 12.0 | 9.7 | 7.6 | 5.3 |
| Maximum | 48.6 | 21.5 | 18.9 | 12.6 | 10.0 | 7.9 | 5.5 |
| Average 10 (♀) | 47.5 | 20.2 | 17.8 | 11.8 | 9.7 | 7.3 | 5.1 |
| Minimum | 46.2 | 20.0 | 17.6 | 11.5 | 9.5 | 7.1 | 5.0 |
| Maximum | 48.3 | 20.4 | 18.0 | 12.0 | 9.8 | 7.5 | 5.5 |
Among females from Departamento de Boaco, none of 18 collected on 20 February was pregnant, whereas three of four obtained on 4 April were gravid (embryos 13, 15, and 17 mm in crown-rump length) as was one (embryo 21 mm) taken on 18 July. Among those from northwest of Diriamba, two of three were pregnant on 30-31 March (embryos 7 and 13 mm in length), whereas only three of eight carried embryos (29, 31, and 34 mm) in mid-August at a time when flying young also were collected. Additionally, a female captured 6 mi WSW Managua on 27 March had an embryo that measured 11 mm.
Four adult males collected on 20 February had an average testicular length of 5.7 (4-7) mm, whereas those of seven obtained in late March averaged 5.0 (4-6) mm; testes of two adults taken on 18 July were 6 and 6.5 mm, and those of three taken in the period 12-15 August were 5 mm in length.
Molossus sinaloae sinaloae J. A. Allen, 1906
Specimens.—Boaco: Santa Rosa, 17 km N, 15 km E Boaco, 300 m, 1. Managua: 1 km N Sabana Grande, 1; 3 mi SW Managua, 1; 8 km SW Managua, 400 m, 3. Rivas: San Juan del Sur, 20 m, 1. Zelaya: S side Río Mico, El Recreo, 25 m, 73.
This mastiff bat can be distinguished easily from the other two large species of Molossus in Nicaragua in that the hairs of the dorsum are relatively long and are pale, frequently white, basally. The species has been reported twice previously from Nicaragua—from Greytown by Miller (1913a:89) and by Goodwin and Greenhall (1964:13), who listed four individuals from Río Grande.
Most of our specimens were taken from buildings. A large series obtained in a house at El Recreo in late June 1966 consisted only of females and young, many of which were nearly full grown; some females still were lactating and at least two were pregnant (on 23 June—crown-rump length of embryos 12 and 14 mm). A group taken from another house at El Recreo (from cracks in the stone wall and from between rafters and the corrugated metal roof) in late July 1966 consisted of adult males, lactating females, and young. Similarly, an adult male, a pregnant female (embryo 14 mm in crown-rump length), and a hairless juvenile were shot, on 16 February 1964, from a small colony in an attic of a large house southwest of Managua; Glossophaga soricina also was taken in this attic. The testes of an adult male captured in June were 6 mm in length; those of four taken in July were 5, 5, 6, and 7 mm, and one obtained in August had testes that measured 3 mm.
Selected measurements of M. s. sinaloae from El Recreo are given in Table 4.
CHECKLIST OF NICARAGUAN BATS
Following is a checklist of the 68 species of bats thus far reported from Nicaragua. Citations are given only to publications that are primary sources of information on Nicaraguan specimens. In some instances, specimens were reported in the literature under a name different than the one here employed; we have mentioned earlier-used names where it seemed appropriate to do so. Taxa preceded by an asterisk are included in the present paper.