BEES OF THE FAMILY ANDRENIDAE— TIMBERLAKE 413 



less raised and less tectiform than in atoposoma. Wings more 

 glassy hyaline, with the fine, short, dark-colored discal setae 

 much sparser than in atoposoma, especially in the submarginal 

 and discoidal cells. Genital armature very nearly identical in the 

 two species. Length 9.5-11 mm. ; anterior wing 7.4-7.8 mm. 



Types. — U.S.N.M. No. 28559. Holotype (female) and allotype, 

 Panamint Valley, Inyo County, Calif., April 1891 (A. Koebele). 



Paratypes : In the collection of the Citrus Experiment Station : 

 1 female, Palm Springs, March 10, 1935; 2 males, 1 female, 

 Andreas Canyon, near Palm Springs, March 24, 1932; 7 males, 

 1 female, Palm Canyon, Borego Valley, San Diego County, March 

 29, 1936; 1 female, 4 miles south of Victorville, June 4, 1938 

 (Timberlake) ; 8 males, 4 females, Tahquitz Canyon, near Palm 

 Springs, March 24, 1936 (C. M. Dammers) ; and 1 female. Pic- 

 ture Rocks, Pima County, Ariz., May 6, 1935 (A. J. Basinger). 

 In the Bohart collection: 4 males, 1 female, Tahquitz Canyon, 

 near Palm Springs, April 16, 1938 (R. M. and G. E. Bohart) ; 

 1 male, Westgard Pass Plateau, Inyo Mountains May 27, 1937 

 (L. D. Phillips) ; and 1 male, Mazourka Canyon, Inyo Mountains, 

 May 25, 1937 (N. W. Frazier). In collection of the University 

 of California at Berkeley: 1 female, 2 miles east of Cathedral 

 City, April 10, 1936; 2 males. Box Canyon, Riverside County, 

 April 4, 1937; and 1 male, Palm Canyon, Borego Valley, San 

 Diego County, March 29, 1936 (E. G. Linsley). 



This bee visits the flowers of Larrea divaricata, from which 

 the female collects pollen. 



MEGANDRENA (ANCYLANDRENA) KOEBELEI, new species 



This differs from the two other species of Ancylandrena in 

 having the basal half of mandibles and large mark on clypeus 

 creamy white, the blister on base of mandibles very large, and 

 a large patch of brown hair present on the mesoscutum. 



Male. — Black, the basal half of mandibles, clypeus except 

 broadly at sides and on anterior margin, and triangular lateral 

 marks ending acutely above level of antennae, creamy white. 

 Apex of mandibles, flagellum beneath, tubercles, tegulae, meta- 

 pleura, sides of propodeum, legs and venter dark ferruginous; 

 the sternum and mesopleura less reddened. Apical margin of 

 tergites broadly subhyaline. Pubescence white, long, fine, silky, 

 and rather dense, mainly concealing surface of face and 

 mesonotum, and only a little less dense on other parts. Hair of 

 vertex, that on apex of tegulae, and a large quadrate patch on 

 posterior half of mesoscutum, brown. Hair on the basal half of 

 tergites 2 to 5 fuscous or black, contrasting with the white hair 



