1S(34.] 21 



luarsin of the ses-ments above smooth and shining ; the two basal seo;- 

 nients above clothed with whitish pubescence, that on the basal segment 

 longest; the third, fourth and fifth segments clothed with black pubes- 

 cence ; apical margin of the sixth segment broadly rounded, strongly 

 reflexed. obsoletely notched in the middle and fringed with long whit- 

 ish pubescence, also a thin patch of long pale pubescence on the disk 

 of this segment; apical segment very slightly and obtusely emarginate 

 ;it tip. Length 5f lines. 



Hah. — New York, Virginia. Three % specimens. Coll. Entom. Soc. 

 Philadelphia, and Mr. E. Norton. 



Readily distinguished by the joints of the intermediate tarsi being 

 subtriaugular and broadly dilated. 



ii. 0. hudsonica. n. sp. 



Male. — Head black, finely and densely punctured, clothed with long 

 ochraceous pubescence which is dense on the face; antennae black, 

 nearly as long as the thorax. Thorax black, finely and densely punc- 

 tured, thickly clothed with long ochraceous pubescence, which is paler 

 and more sparing beneath ; tegulas black, clothed with ochraceous pu- 

 bescence. Wings subhyaline, the marginal cell and the apical margins 

 clouded; nervures black. Legs black, thinly clothed with ochraceous 

 pubescence ; apical joints of the tarsi rufous. Abdomen elongate, 

 clavate. much narrowed towards the base and incurved at the apex ; 

 black, shining, densely and minutely punctured, the apical margin of 

 the segments above smooth and shining ; basal segment above clothed 

 with ochraceous pubescence, the remaining segments with black pubes- 

 cence, that on the two apical segments mixed with fuscous and ochra- 

 ceous ; apical margin of the sixth segment broadly rounded, reflexed, 

 obtusely notched on the middle and sulcate on the disk ; apical seg- 

 ment slightly emarginate at tip ; the margin of the second segment 

 beneath is produced into a large semicircular flattened plate. Length 

 5 lines. 



Hah. — Hudson's Bay Territory. One specimen. Coll. Mr. E. Norton. 



Resembles 0. latitarsia in its general form, but quite distinct. These 

 two species, especially the former, have much the appearance of certain 

 males of Megacliile, e. g. M melano^ihsea Smith, but the maxillary 

 jtalpi are 4-j(iinted. 



