88 PROCEEDINGS OF THE NATIONAL MUSEUM. 



First or rufus-gronp. — Largest members of the genus, with length of 

 forearm ranging from 43 to 61 mm, greatest length of sknll from 19 to 23 

 mm ; sknll with highly developed sagittal crest, and with rostral breadth 

 across canines 5 mm or more. 



MOLOSSUS RUFUS GeofiEroy. 



1805. Molossus rufus Geopfeoy, Ann. Mus. Hist. Nat., Paris, vol. 6, p. 156. 

 (Cayenne.)^ 



1805. Molossus castaneus Geofproy, Ann. Mus. Hist. Nat., Paris, vol. 6, p. 155. 

 (Paraguay.) 



1823. Molossus ursinus Spix, Sim. et Veepert. Brasil Sp. Nov., p. 59. (Vicinity 

 of Para, Brazil.) 



1827. Dysopes alecto Temminck, Monogr. de Mam'm., vol. 1, p. 231. (Interior of 

 Brazil.) 



1844-46. Molossus myosuros Tschudi, Faiina Peruana, Mamm, p. 83. (Peru.) 



1891. Molossus fluminensis Lataste, Ann. Mus. Civ. Stor. Nat., Genova, ser. 

 2, vol. 10, p. 658. (Rio Janeiro, Brazil.) Name based on a normal speci- 

 men of Molossus rufus whose characters differ in important details from 

 those in Dobson's faulty description. 



Size maximum for the genus; forearm in males 48.5-51 mm, in 

 females 47-51; greatest length of skull in males 21.4-23, in females 

 20.4-22; general color a reddish brown varying in different individuals 

 from russet to mummy-brown, the blackish phase apparently unusual. 

 Specimens examined from Cayenne, Peru (type of M. myosuros; 

 forearm 48 mm), southern Brazil (Sao Paulo), and Paraguay (Sapucay 

 and Vnia Kica). 



MOLOSSUS NIGRICANS MiUer. 



1902. Molossus nigricans Miller, Proc. Acad. Nat. Sci. Philadelphia, p. 395. 

 September 12, 1902. (Acaponeta, Topic, Mexico.) 



Like Molossus rufus but color usually a deep, blackish brown. 

 Specimens examined from Tepic (Acaponeta), Vera Cruz (Catemaco 

 and San Andres Tuxtla), and Yucatan (Chichenltza and Yaxcash). 



MOLOSSUS PRETIOSUS MUler. 



1902. Molossus pretiosus Miller, Proc. Acad. Nat. Sci. Philadelphia, p. 396. 

 September 12, 1902. (La Guaira, Venezuela.) 



Size not so great as in Molossus rufus; forearm in males 44.5-47.5 

 mm, in females 43.5-46; greatest length of skull in males 20.5-21.5, in 

 females 19-20.7; general color a rich dark brown varying from a red- 

 dish seal-brown almost to chestnut, the blackish phase not unusual. 

 Specimens examined from La Guaira, Venezuela, and vicinity. 



1 Thomas (Ann. and Mag. Nat. Hist., ser. 7, vol. 8, p. 437, November, 1901) assumes that the animal 

 originally came from Brazil, but Geoflroy expressly states (p. 154) that his species of Molossus, other than 

 those known to Azara, were sent from "North America, Surinam, and chiefly from Cayenne." A male 

 from Cayenne and two males from "America," which I examined in the Paris Museum in 1904 (the two 

 without exact locality marked " type," but the authenticity of this indication open to question) represent 

 a large form like rufus (forearm in the two "types " 49 and 50 mm). Further material from French Guiana 

 is needed to show whether Molossus rufus and the Paraguayan M. castaneus are distinct. 



