356 THE CANADIAN ENTOMOLOGIST. 



head greyish-white, pale fuscous on middle of face; hair of thorax 

 white, with a creamy tint above, and no dark hair intermixed; 

 tegulae piceous, with a greenish spot in front; wings dusky hyaline, 

 reddish, distance from base of first s.m. to insertion of first r.n. as 

 great as length of first t.c; b.n. going just basad of t.m.; legs red- 

 dish black, not at all metallic, with pale pubescence, reddish on 

 inner side of tarsi; abdomen closely but rather shallowly punctured, 

 the punctures going nearly to the margins of the segments; sub- 

 lateral region with quite long black hair; ventral scopa black. The 

 clypeal margin is entire, and the mandibles are 3-dentate; the area 

 of metathorax is densely granular basally, but more shining 

 apically. 



Hah. — Nova Scotia (Ent. Club), 44-12. I have been much 

 perplexed to decide whether this could be the female belonging to 

 the male from Nova Scotia described as O. simillima by Smith. 

 This may indeed be the case, but the type of simillima must be 

 considered to be the female, which may not be conspecific with the 

 male. Smith says that the female simillima is so like the European 

 O. caenilescens that it is difficult to distinguish; but novaescotiae 

 is easily separated from caerulescens by the broader, less deeply 

 punctured abdomen, without white marginal fringes or bands. 

 In our fauna it is 0. purpurea Cresson, which closely resembles 

 caerulescens.^ In my brief notes on Smith's types, I observed 

 that according to Robertson's tables the female type of simillima 

 w^as an Osmias. str., while the male was a Monilosmia. Dr. Grae- 

 nicher has, however, obtained at Milwaukee, Wisconsin, what he 

 regards as true simillima, and has both sexes from the nest. The 

 male of this species is a Monilosmia, but the female h as a black 

 ventral scopa and clypeus with entire margin, quite contrary to 

 Robertson's definition of Monilosmia. The Milwaukee females 

 are larger than novaescotiae, with a dark greenish abdomen, and 

 the hind margins of the segments more broadly smooth. They 

 are very unlike 0. caerulescens. They have the hair on inner side 

 of middle tibiae black; in novaescotiae it is pale, with a reddish tint. 

 The b.n. goes more broad of the t.m. than in novaescotiae. There 

 is no doubt, I think, that the Milwaukee ''simillima' is distinct 

 from novaescotiae, but I find that except for the smaller amount of 

 dark hair on the head (a variable character) it is scarcely or not 

 to be separated from the western 0. densa Cresson. This probably 

 explains why we have never been able to find a male for densa] 



*Can it be that 0. purpurea is cœrulescens ? From the British Museum I 

 have a female marked North America, 40, 4-2, 484, and it is quite impossible to 

 distinguish it from European cœrulescens, while, at the same time, it agrees 

 with Cresson's description of purpurea. It has the shiny mstathoracic area of 

 cœrulescens, which Smith expressly says is wanting in simillima. 



