Cockerell, Theodore D. A. (Theodore Dru Alison), 1866-1948.Sumner, Ruth.Lutz, Frank Eugene, 1879-1943.2005-10-062005-10-061931http://hdl.handle.net/2246/303715 p. : ill. ; 24 cm.Includes bibliographical references.pt. 3. The genus Hylaeus (Prosopis).1384857 bytesapplication/pdfen-USQL1 .A436 no.490, 1931Hylaeus -- Rocky MountainsBees -- Rocky MountainsInsects -- Rocky Mountainstext