764 Mr. T. D. A. Cockerell — Descrij)tions and 



Osmia clarescens, sp. n. 



$ . — Length about 9 mm. 



Steel-blue, with white hair, mixed with long black hairs 

 on face, vertex, and dorsum of thorax ; hair of pleura and 

 sides of metathorax entirely white. Legs very blue, inner 

 side of tarsi with dark chocolate hair. Mandibles tridentate, 

 but the inner tooth is broad and truncate and sometimes 

 looks like two ; clypeus normal ; tegulse largely blue. 

 Wings strongly dusky ; b. n. meeting t.-m. ; apical part of 

 abdomen above with a good deal of black hair ; ventral scopa 

 black, but glittering white hair at sides of abdomen. 



^ . — Length about 7^ mm. 



Similar to the female, except in the usual sexual characters ; 

 bright steel-blue, legs very blue ; pubescence white, but 

 mixed with long black hairs on face, vertex, and dorsum of 

 thorax ; hair of clypeus silky white, but on each side are 

 some long black hairs ; flagellum black ; middle tarsi 

 simple ; hind basitarsi toothed. Apical part of abdomen 

 with some black hairs among the light ; sixth segment feebly 

 notched, seventh bidentate ; first ventral shallowly emar- 

 ginate, third ventral with long white hair in the emargina- 

 tion, conspicuous when not hidden by the overlapping second 

 segment. 



Hab. Claremont, California [Baker] ; 28 ? , 3 c? • The 

 type is a female. 



The female greatly resembles that of O. color aclella, Ckll., 

 but is easily separated by the black hair of head and thorax 

 above. It may also be compared with O. phacelice, Ckll., 

 from which it is known by the larger size and blue legs, and 

 with O. melanotricha, Lov. & Ckll., from which it is known 

 by the blue legs and black hair of thorax above. The male 

 is extremely like 0. vallicola, Ckll., but differs at once in 

 the mandibles, which are rather strongly curved near the 

 end, with a short apical tooth (little curved and with a long 

 apical tooth in vallicola), and the long black hairs at sides of 

 clypeus are wholly wanting in vallicola. It also closely 

 resembles O. wheeleri, Ckll., but differs by the black hairs at 

 sides of clypeus and the conspicuous short white hair on 

 inner side of hind tibise. 



Osmia basilissa, sp. n. 



$ . — Length 9 mm. or slightly more. 



Robust ; magnificent deep purple, including the legs, with 

 coarse entirely black pubescence ; mandibles with two large 

 outer teeth and a binodular short and broad inner one ; 



