Records of Bees. 449 



faintly brownish Ijeneath, but quite dark ; legs not metallic ; 

 abdomen narrower and less shininfj ; marginal cell longer and 

 narrower apicallj. Tiie head is rather large ; there are dark 

 hairs about tl e ocelli ; the thorax is wholly without dark 

 hair. There is a dark stain at the apex of the marginal cell. 

 Notch in sixth abdominal segment strong. 



In the Florissant table it runs to 0. faceta, but diflfers in 

 the antennge, &c. Compared with 0. Wheelert, the abdomen 

 is duller and the sixth segment differently shaped. The 

 clypeus is practically black; in Wheeleri it is lalue-grfen. 

 In the Boulder County table, 0. enena runs to aprilina, from 

 which it differs in the form of the abdomen, the colour of the 

 pubescence, &c. 



I Jul). Florissant, Colorado, June 23, 1907 {S. A. Ruhwer). 



Osmia vaUicola, sp. n. 



^ . — Length about 8 mm. 



(Superficially similar to O. mertensire, but smaller, with the 

 flagellum wholly dark, the apical tooth of mandibles longer, 

 the head and thorax greenish blue ; the vertex, front, and 

 thorax above with scattered very long black hairs ; upper 

 part of pleura with the hair black; marginal cell longer; 

 second submarginal cell very long. The legs are strongly 

 metallic ; the abdomen is very shiny, and of the same tint 

 as that of mertenslce ; sixth segment rather feebly notched ; 

 venter and tarsi normal. 



In the Florissant table runs to 3, and runs out because of 

 hair of pleura half black and half light. In the Boulder 

 County table it runs to 0. propinqua, hut the flagellum is 

 not moniliforni, and there are many other differences. 

 {0. propinqiia does occur at Florissant, both sexes having 

 been taken by Mr. Rohwer from flowers of iSali.c brachy- 

 carpa, June 11, 1907.) 



JIab. Florissant, Colorado, at flowers of Eibes vaUicola^ 

 June 11, 1907 {S. A. Rohioer). 



Osmia nigrifrons, Cresson, 1878. 



Three females at flowers of Senecio tridenticulatus, Floris- 

 sant, Colo., June 14, 1907 {S. A. Rohioer). 



Osmia Wheeleri, Ckll., 1906. 



One male at flowers of Castilleia integra, Florissant, ( 'olo., 

 June 23, 1907 (S. A. Rohioer). 



Osmia Jlorissavticola, Ckll., 1906. 



Two females at flowers of AragaUiis Lamberti (sens, lat.), 

 Florissant, Colo., June 1907 (7'. V. A. Cockerel!). 



