192 BULLETIN 144, UNITED STATES NATIONAL MUSEUM 



Measure77ients. — For measurements see tables, pages 195 and 196. 

 Specimens examined. — Total number 40, from the following locali- 

 ties: 



ARGENTINA: Chubut, Gaimaa, 2 ale. (B. M.) ; Cordoba, 4 ale. (B. M.), 

 8 ale. (U.S.N.M.) ; Mendoza, 1 ale. (B. M.), 1 ale. (M. C. Z.), 3 ale. 

 (U.S.N.M.) ; Merced, Salta Province, 1 ale. (B. M.) ; Neuquen, 1 ale. 

 (B. M.) ; northwestern Argentina, 2 ale. (B. M.) ; Pampa Grande, 

 2 ale. (B. M.) ; Tucuman, Catamarca Province, 5 skins (B. M.) ; Upper 

 Cachi, Salta Province, 1 skin, 2 ale. (B. M.) ; Valle de Lerma, Salta 

 Province, 1 skin (B. M.). 



BOLIVIA: Paratani, 1 skin (B. M.). 



URUGUAY: Dept. of Soriano, 1 ale. (B. M.) ; no exact locality, 4 ale. 

 (U.S.N.M.). 



Remarks. — East of the Andes the increasing dryness of the climate 

 finds a response in the brightening hue of the chiloensis bats. A skull 

 from Salta Province, Argentina (6.5.8.2 B. M.) lacks the minute 

 middle premolar on both sides of the upper jaw, while the first pre- 

 molar stands fully in the tooth row and fills the entire space between 

 canine and third premolar {p*). 



MYOTIS CHILOENSIS ATACAMENSIS (Lataste) 



Vespertilw atacamensis Lataste, Aetes Soc. Sci. Chile, Santiago, vol. 1 (1891), 

 p. 79, 1892 (Atacama, Chile). — Phllippi, Anales Mus. Nac. de Chile, sect. 1, 

 zool., No. 13, p. 5, pi. 1, fig. Or-d, 1896. — Teotjessabt, Catal. Mamm. viv. 

 foss., p. 130, 1897 (as synonym of V. nigricans). 



Myotis atacamensis Trotjessart, Catal. Mamm. viv. foss., suppl., p. 94, 1904. 



Type locality. — Atacama, Chile. 



Type specimen. — Mounted specimen, No. 277, National Museum of 

 Chile. Collected February, 1885. 



Distribution. — This bat seems to be common in the vicinity of San- 

 tiago and Valparaiso, Chile, but how much farther north it occurs at 

 the lower levels can not yet be said. With increasing dryness north- 

 ward and lack of suitable shelter it no doubt becomes rare or absent 

 altogether at the lower elevations. A single specimen from Ollantay- 

 tambo, Peru, altitude 9,400 feet, appears to be not distinguishable 

 from the Chilean skins. 



Diagnosis. — Similar in size and proportions to Myotis cMloensis 

 cMloensis but color a light dull (not yellowish) brown above, grayish 

 below. 



Color. — General color above a grayish brown, ranging from nearly 

 "wood brown" (Ridgway, 1912) to drab; the tips of the long hairs 

 faintly glossy. Below, the general color of the surface is grayish 

 white, more or less washed with brownish, especially at the sides and 

 under the chin. The individual hairs are plumbeous at the base 

 tipped with grayish white or brownish white, except at the extreme 



