AMERICAN BATS OF THE GENERA MYOTIS AND PIZONYX 15 



The fact that the wide-ranging species break up so readily into 

 subspecies corresponding to areas of different climatic conditions 

 perhaps indicates that the bats of this genus are very little migratory 

 and that such migration as there may be probably consists in nothing 

 more than a local withdrawal to certain not-distant caves for hiber- 

 nation, or in some cases in an invasion of near-by alpine heights 

 during the warm months at the close of the breeding period. 



NOMENCLATURE OF THE AMERICAN SPECIES OF MYOTIS 



No less than 102 trivial names have been given to American bats 

 of the genus Myotis. Only 39 of these are here regarded as the valid 

 designations of recognizable forms. We are proposing 7 new names 

 for species and races not hitherto discriminated. Tiie total number 

 is thus raised to 109 names for 46 forms, an average of nearly 

 2.4 names to a form. This average, among the genera of American 

 mammals, which have been recently revised, is high.* It may be 

 taken as some index to the difficulty and confusion which have 

 attended the study of these bats. 



The following are the names which have been applied to species 

 and subspecies of American Myotis: 



Aenobarbus (VespertUio) Temminck, Monogr. de Mamm., vol. 2, p. 

 247, pi. 69, fig. 4, 1840. The specimen on which this name was based 

 is presumably still in the Leiden Museum; it came from an unknown 

 locality in South America. Though the tooth formula is not given, 

 Temminck's figure of the head shows the rjharacteristic long narrow 

 tragus of Myotis, while the proportions of tail to total length and 

 the description of the color leave little doubt that the name is a 

 synonym of M. albescens. 



Affinis (VespertUio) H. Allen, Monogr. Bats North Amer., Smith- 

 sonian Misc. Coll., No. 165, p. 53, June, 1864. Examination of the 

 type specimen (No. 5342, U. S. Nat. Mus.) shows it to be referable 

 to the eastern race of Myotis lucifugus. 



Agilis {VespertUio) H. Allen, Proc. Acad. Nat. Sci. Philadelphia, 

 1866, p. 282. This name, based on specimens from Mirador, Vera 

 Cruz, was applied to the Mexican representative of M. calif omicus. 

 It is antedated by VespertUio meaeicamis Saussure, 1860. 



Alascensis {Myotis livcifugus) Miller, North Amer. Fauna, No. 13, 

 p. 63, October 16, 1897. The only name applied to the dark sub- 

 species of M. lucifugus occuring on the humid northwest coast. 



Albescens {VespertUio) E, Geoffroy, Ann. Mus. d'Hist. Nat. Paris, 

 vol. 8, p. 204, 1806. This name, based on the " Chauve-souris 



* In some of the other groups it is as follows : Ochotona, 1.04 ; Thomomys, 1.1 ; Lepori- 

 dw, 1.3; Oryzomys, 1.3; Spilogale, 1.3; Peromyscus, 1.5; Vesper tilionine bats other than 

 Myotis, 1.7 ; Talpidm, 1.8. 



