254 BULLETIN 57, UNITED STATES NATIONAL MUSEUM. 
Geographic distribution. — Southeastern Africa, Madagascar, Bour- 
bon, and Mauritius; also Tropical America (Peru and Cuba). 
Number of forms. — Eight forms are currently referred to this 
group. 
Characters. — Dental formula : 
-2 -. 1.— 4567 . 1 
12(3). 1.-24567 * 3 
1-1 1-1 
3° r 2 
2 ,C 1 
1 
pm 
1-1 
2 - 9 ’ 
m 
3-3 
:30 or 28* 
3-3 
Except in the constant absence of 
the small upper premolar this genus 
does not differ appreciably from Nyc- 
tinomus. The ears are usually smaller, 
however, and are never joined across 
forehead. The skull of Mormopterus 
minutus is shown in fig. 44. 
Species examined. — M ormopterus 
acetabidosus (Demarest), M. alli- 
venter (Dobson), M. jugularis 
(Peters), M. kalinowskii (Thomas), 
and M. minutus (Miller). 
Remarks. — The constant absence of 
the small upper premolar and the 
generally smaller size of the ears as 
compared with those of Nyctinomus 
seem important enough characters to 
warrant the recognition of this genus. In the two known American 
species there are only 2-2 lower incisor teeth. 
Fig. 44.— Mormopterus minutus. Adult 
male. Trinidad, Cuba. No. 4915. Amer. 
Mus. Nat. Hist, x 2}. 
Genus PLATYMOPS Thomas. 
1900. Platymops Thomas, Ann. and Mag. Nat. Hist., Ttli ser., XVII, p. 499, 
May, 1906. 
T ype-species. — Platymops macmillani Thomas. 
Geographic distribution. — Northeast Africa (between Adis Ababa 
and Lake Rudolf). 
Number of forms. — The type is the only species known. 
Characters.— Dental formula : 
- 2 1- 1. - 2 -4 5 6 7 .1 - 1 1 - 1 2-2 3 - 3__ QA 
12 -1. - 2 - 4 5 6 7 * 2 - 2 1 - 1’ pm 2-2 3-3 
Upper incisors bifid, more than half as high as canines, wider apart 
at base than at tip, separated from canines and from each other by 
space about equal to their greatest diameter; crown about half as 
long as high, its breadth at base slightly less than length; posterior 
surface of crown rather strongly concave; outer lobe slightly more 
than half as large as inner, its tip diverging a little outward. Lower 
incisors subequal, imbricated, forming a continuous, slightly convex 
