Produced by Chris Curnow, Tom Cosmas, Joseph Cooper and the Online Distributed Proofreading Team at http://www.pgdp.net A Synopsis of the American Bats of the Genus Pipistrellus BY E. RAYMOND HALL and WALTER W. DALQUEST University of Kansas Publications Museum of Natural History Volume 1, No. 26, pp. 591-602, 1 figure in text January 20, 1950 University of Kansas LAWRENCE 1950 UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY Editors: E. Raymond Hall, Chairman, Edward H. Taylor, A. Byron Leonard, Robert W. Wilson Volume 1, No. 26, pp. 591-602, 1 figure in text January 20, 1950 UNIVERSITY OF KANSAS Lawrence, Kansas PRINTED BY FERD VOILAND, JR., STATE PRINTER TOPEKA, KANSAS 1950 [Illustration: Union Label] 23-1546 A Synopsis of the American Bats of the Genus Pipistrellus By E. RAYMOND HALL AND WALTER W. DALQUEST Four nominal species of the genus _Pipistrellus_ are currently recognized in North America. They are _Pipistrellus subflavus_ (F. Cuvier) of eastern North America, _Pipistrellus hesperus_ (H. Allen) of western North America, _Pipistrellus veracrucis_ (Ward) from Veracruz, Mexico, and _Pipistrellus cinnamomeus_ Miller from Tabasco, Mexico. In the past three years, specimens have been obtained in Veracruz (by Dalquest) of each of the southern species. One of these, _P. cinnamomeus_, previously was known from a single specimen; the other, _P. veracrucis_, was known only from six specimens which now are lost or misplaced. The results of our study of these recently acquired Mexican specimens constitute our principal contribution in this paper; we have done little more with the material from the United States and Canada than to codify the findings of other mammalogists with respect to the systematic status and geographic distribution. Study of the available specimens reveals that there are only two species, _Pipistrellus hesperus_ and _Pipistrellus subflavus_; _Pipistrellus veracrucis_ proves to be only a subspecies (geographic race) of _P. subflavus_, and _Pipistrellus cinnamomeus_ proves to be a species of another genus, _Myotis_ (see Hall and Dalquest, page 583 of this volume). Genus +Pipistrellus+ Kaup