NO. 2264. BEES IN THE NATIONAL MUSEUM. 3—COCKERELL. 215 



MEGACHILE ALBITARSIS Cresson. 



Mexico (Baker collection, 1785). A male M. rhodopus Cockerell 

 carries the same number. 



MEGACHILE LATIMANUS Say. 



Mexico (Baker collection, 2320). Both sexes. This is identical 

 with the Eocky Mountain species which I have regarded as latl- 

 rnanus; it is possible that the true species of Say is separable, but I 

 have not the materials on which to reach a decision. 



MEGACHILE NIGROMIXTA, new species. 



Male. — Length about 8 mm., anterior wing G.5; black, includiug 

 the legs (anterior tarsi simple), the long slender flageiium obscurely 

 brownish beneath ; head broader than thorax ; face and front covered 

 with long yellowish-white hair, the upper part of clypeus also w^ith 

 very long black hairs, largely mixed with the others, and not forming 

 a definite fringe; vertex with inconspicuous long dark hairs and 

 sparse short pale ones; vertex broad, closely punctured, but glisten- 

 ing; thorax above well punctured, but somewhat shining; hair of 

 thorax pale, mixed with black above, especially on scutellum, and a 

 patch of black hair on middle of pleura; tegulae black; wings dilute 

 fuliginous, the costal region darker, shining violaceous; legs with 

 pale hair, yellowish on inner side of tarsi ; anterior coxae flattened 

 and shining in front, with stout spines ; middle and hind femora and 

 hind tibiae stout; abdomen shining, segments 1 to 4 with pale ochre- 

 ous hair-bands at sides only ; disk of second segment with long black 

 hair; fifth segment with an entire band; sixth above covered with 

 ochreous hair, the keel obtusely bilobed; venter with two entire hair- 

 bands. 



Mexico (type), from Baker collection (1785). Also one from 

 Guatemala (Baker collection, 1783). Superficially like M. gua- 

 lanensis Cockerell, but easily separated by the much larger head, 

 darker wings, and bilobed end of abdomen. 



Type.—C^t. No. 21684, U.S.N.M. 



MEGACHILE KNABI, new species. 



Male. — Length about 10 mm. ; anterior wing 6.8 ; black, moder- 

 ately robust, antennae slender, and simple; face and front covered 

 with shining white hair, and cheeks below with a stiff dense fringe 

 of the same; mandibles broadly triangularly expanded below, the 

 margins of expanded part conspicuously hairy, the inner slope with 

 ii dense pale yellowish fringe; vertex with strong, very dense punc- 

 tures, mesothorax and scutellum with the same; thorax with white 

 hair, thin dorsally, not mixed with black ; base of metathoracic area 

 rugulose; tegulae black; wings dusky, especially toward apex; legs 

 with pale hair; anterior coxae with rather short spines; anterior 



