MOLOSSUS. 31 
Of the adaptation of their structure to their habits, Mr. Dobson observes that their 
long narrow wings and their power of varying the spread of the interfemoral membrane 
gives them great advantages in quickly altering the direction of their flight. “Of all 
Bats the Molossi appear especially suited by their peculiar conformation for capturing 
the most rapidly flying insects, which no doubt form the greater portion of their food. 
Their large and very strong acutely tubercular teeth would enable them to crush with 
ease the hard armour of the larger Coleoptera ”*. 
The genus Molossus is characterized by the union of the premaxillaries and conse- 
quent closeness of the upper incisors, as well as by the very narrow tragus and scarcely 
grooved upper lip. It is a purely Neotropical type, of which nine or ten species range 
from the River Plate to Mexico. Of these, the Central-American species are :— 
1. VM. rufus. Antitragus circular, as high as broad; incisors 3, premolars =}. 
Forearm 2"°10. Fur short, deep brown, red-brown, or fulvous. 
2. M. nasutus. Antitragus circular, as high as broad; incisors 4, premolars =, 
2—2 
Forearm 2”. Fur moderately long, deep brown above, paler beneath. 
3. MW. abrasus. Antitragus semicordate, longer than high ; incisors 7, premolars == 
2—2¢ 
Forearm 2'-45. Fur short, intensely black above and below. 
1. Molossus rufus. 
Molossus rufus, Et. Geoffroy, Ann. du Mus. vi. p. 154 (1805, deser. orig.)’; Gervais, Exp. de Cas- 
telnau, Mamm. p. 58, t. xii. figs. 4, 4a”; Peters, Monatsb. Ak. Berl. 1865, p. 575°; Dob- 
son, P.Z. 8. 1876, p. 709*; Cat. Chir. Brit. Mus. p. 410°. 
Molossus obscurus, Et. Geoffroy, Ann. du Mus. vi. p. 155 (1805, descr. orig.)"; Peters, Monatsb. 
Ak. Berl. 1865, p. 575”. 
Molossus ursinus, Spix, Sim. et Vesp. Bras. p. 59, t. xxv. fig. 4 (1828, descr. orig.)’. 
Dysopes velox (Natterer), Temminck, Mon. de Mamm. i. p. 134 (1836, descr. orig.)”’. 
Hab. Mexico (Berkenbusch, Mus. Berol.), Oaxaca (Sallé, Mus. Brit’); Guatemaa, Vera 
Paz (Salvin, Mus. Brit.>).—West Inpizs®; Ecuapor® ; Guiana’ ; Braziu® ; Boxtvia?. 
The Red Mastiff-Bat, as it has been called, was first named from specimens in the 
Paris Museum by the elder Geoffroy St.-Hilaire!; but, as Professor Peters observes, 
Spix’s description® is the first that is recognizable. Gervais’s figures of the skull and 
dentition of Geoffroy’s type? show, however, that the species are identical ; and his name 
may therefore be retained. 
The range of I.’ rufus seems to extend throughout great part of the tropical regions 
of Central and South America. Along with the typical form, and also extending to 
the islands, is found a smaller race, which Geoffroy described as JZ. obscurus®, in which 
the fur between the humerus and forearm extends further over the wing-membrane, and 
* Cat. Chir. Brit. Mus. p. 403. 
