206 PROCEEDINGS OF THE NATIONAL MUSEUM vol. iio 



and Emballonuridae were somewhat less numerous during the same 

 period. The VespertiHonidae became abundant somewhat later. 



Family Vespertilionidae 



According to Revnhod (1919, p. 94), the genus Stehlinia [=Nycter~ 

 ohius Revilliod and Revilliodia Simpson (Handley, 1955a, p. 128)] of 

 the Quercy fauna of the Upper Eocene or Lower Oligocene of Europe 

 is the most ancient known vespertilionid. It has cranial characters 

 of the Vespertilionidae, but is distinguished from modern genera by 

 several primitive characters, including very elongated rostrum, rela- 

 tively very long premolar series, and 2-rooted P^ It most closely 

 resembles some of the small species of Myotis, which is generally con- 

 ceded to be the most primitive living genus of the family. 



True Myotis appears for the first time in the Stampien and Aqui- 

 tanien faunas of the Middle and Upper Oligocene of Europe [Myotis 

 salodorensis Revilliod (1919, p. 94) and Myotis insignis von Meyer 

 (Revilliod, 1922, p. 166)]. Other Myotis have been described from 

 the Middle Miocene of Europe [Myotis antiquus Gaillard (1899, p. 8) 

 and Myotis sancti-alhani Viret (1951, p. 19)], and Myotis-\C&.e remains 

 occur in Lower Miocene beds in Florida (Lawrence, 1943, p. 364). 

 Some of the Recent species of Myotis (M. bechsteinii, M. mystacinus, 

 and M. oxygnathus) were possibly derived by Pliocene or Lower 

 Pleistocene time (e.g., see Heller, 1930, p. 154; Kormos, 1937, p. 33; 

 and Kowalski, 1956, p. 331), although most late Tertiary and Quater- 

 nary material has been described as now extinct species (e.g., see 

 Heller, 1936, p. 113; Kormos, 1934, p. 306; Kowalski, 1956, p. 331; 

 Sickenburg, 1939, p. 8; and Wettstein, 1923, p. 40). 



Another primitive vespertilionid genus, Miniopterus, is thought to 

 have been recognizable as far back as the Miocene epoch (M. fossilis, 

 Zapfe, 1950, p. 60). The Lower Pliocene Mystipterus (Hall, 1930, 

 p. 319) from Nevada, first supposed to be related to Miniopterus, 

 subsequently has been shown to be an insectivore (Patterson and 

 McGrew, 1937, p. 256). 



The oldest Eptesicus-like remains are from Lower Miocene beds 

 of Florida (Lawrence, 1943, p. 367). Other Eptesicus-like genera, 

 Samonycteris (RevUliod, 1919, p. 95) and Pareptesicus (Zapfe, 1950, 

 p. 58), have been described from the Miocene of Europe. From the 

 Upper Pliocene of Arizona comes Simonycteris (Stirton, 1931, p. 27), 

 also possibly a relative of Eptesicus. The most ancient remains at- 

 tributed to true Eptescius are those discovered in the Pliocene or Lower 

 Pleistocene of Hungary (Kormos, 1930a, p. 41), Brown (1908, p. 174) 

 regarded Middle Pleistocene material from the Conard Fissure of 

 Arkansas as being only subspecifically distinct from the Recent 

 Eptesicus Juscus. Gidley and Gazin (1938, p. 11), with more abundant 



