724 ZOOLOGY INSECTS. 



103. MACROTERA ALBIPENNIS. 

 Perdita ? albipennis, CRESS., Traus. Am. Ent. Soc., i, 386. 



3 9 specimens; New Mexico; Dr. Oscar Loew. 



104. MONUMETHA BOREALIS. 

 Monuwctha borealis, CRESS., Proc. Ent. Soc. Phila., 18G4, 388. 



1 9 specimen; Eastern Nevada ; 1872; Dr. H. C. Yarrow. 



105. MONUMETHA ARGENTIFRONS. 

 Monnmetha argentifrons, CRESS., Proc. Ent. Soc. Phila., 1864, 387. 



1 (? specimen; Colorado; 1873; Dr. J. T. Rothrock. This is proba- 

 bly the i of borealis. 



106. OSMIA BUCEPHALA. 



Osmia bticephala, CRESS., Proc. Ent. Soc. Pliila., 1864, 17. 



1 9 specimen; Colorado; 1873; Dr. J. T. Rothrock. 



107. LITHURGUS APICALIS, sp. nov. 



9. Black; the face with a transverse ridge, with the sides elevated 

 into a prominent obtuse tubercle, and beneath a large, quadrate, flattened, 

 smooth, shining space, having a few large scattered punctures; at base 

 of antennae, down the sides of the face, and on the margin of the clypeus 

 covered with dense, whitish pubescence ; that on the latter intermixed with 

 fulvous; cheeks, sides of thorax and of metathorax, and postscutellum 

 clothed with long, whitish pubescence; thorax convex, densely and rather 

 coarsely rugose ; wings subhyaline ; legs clothed with a pale pubescence ; 

 that on tarsi beneath fulvous; abdomen depressed, much flattened and ex- 

 cavated at base, shining, finely and closely punctured on the sides, smooth 

 on the disk of the segments, the apical margins of which have a narrow 

 baud of white pubescence, generally interrupted medially; apical segment 

 above densely covered with a fulvo-fuscous pubescence; ventral scopa 

 dense and whitish. Length, 6-8 lines. 



2 9 specimens; Colorado, New Mexico ; Dr. H. C. Yarrow, C. E. Aiken. 

 This is closely allied to gibbosus, .Sm., also found in Colorado, but is readily 

 distinguished by the fulvous apex of the abdomen; in yibbosus, the apical 

 segment is black. 



