124 Mr. T. D. A. Cockerell — Descriptions and 



thorax above light oclireoiis, witli black hair sparsely inter- 

 mixed on scutellutn and hind part of mesothorax ; tegulse 

 black. Wings clear in the middle, but with the hind margin 

 broadly and very distinctly inf'uscated ; a very dark streak 

 in upper part of marginal cell. Hair of legs black, dark 

 reddish on inner side of tarsi. Abdomen short and convex, 

 shining dark blue, with slight crimson or purple tints on 

 second and third segments : hair of tirst segment pale except 

 at extreme sides ; of second black at extreme base, at sides, 

 and apex, but long and pale on disk ; remaining segments 

 with black hair. 



In my table of Boulder County Osmia (Univ. of Colo. 

 Studies, ined.) this runs to 0. nigrifroiis and O. gaillardice^ 

 resembling the latter in superficial appearance (especially the 

 shining abdomen), but differing in the colour of the pubes- 

 cence, the clypeal pit, &c. The second r. n. joins the second 

 s.m. nearer its end in gmUardioi than in leonis. In gail- 

 lardice the little brushes of hair from beneath the clypeus are 

 yellow ; in leonis they are pure black. From nigrifrons the 

 new s])ecies is more easily separated; among other things the 

 ])unctures of the face are finer and smaller in nigrifrons than 

 in leonis. There is evident affinity with 0. juxta^ Cresson, 

 but the admixture of black hair on the thorax above and the 

 light hair on second abdominal segment, as well as the clypeal 

 ])it, should suffice to distinguish leonis from that insect. 



Hah. Campus of University of Colorado, Boulder, Colorado, 

 at flowers of Taraxacum taraxacum, May 8 {Edna Baker) . 



On the hair of the abdomen were some mites of the genus 

 2\'ichotarsus, which Mr. N. Banks says are T. osniiie, Duf., or 

 more probably a new species allied to it. 



Osmia integrella, sp. n. (possibly universitatis var.) 



^ . — Length 10 or 11 mm. 



Steel-blue, with the head and thorax above, the first abdo- 

 minal segment, and a strong tinge or suffusion on the apical 

 part of the other segments green ; hair long, the pale hair 

 white, not ochreous, no admixture of black hair on head and 

 thorax above, except that some black hair on upper part of 

 cheeks has a few outlying hairs on extreme sides of vertex ; 

 cheeks with hair white, but some black behind and above. 

 Antennae black, flagellum not moniliform ; clypeus normal; 

 pleura with white hair except on posterior margin, starting 

 Avith a patch just beneath wings, where it is black; extreme 

 sides of metathorax with black hair; tegulse green in front. 

 Wings little dusky. Legs black, not at all metallic, their 



