Studies of North American Bees 3 



in the female. Hence Melanostclis Ashmead is to be regarded as 

 a synon3^m of Chelynia Provancher, the latter name having ten 

 years priority, and the group is here recognized as a subgenus. 

 The Nearctic species having the second type of venation have been 

 commonly referred to the genus Stelis. This genus was described 

 by Panzer in 1806 (Kritische Revision der Iiisectenfaune Deutch- 

 lands, II, p. 246), and the only included species was vS". atterima, 

 which is thus necessarily the type. But vS". atterima, as well as 

 several Palaearctic species, have the mesoscutellum bearing lateral 

 teeth behind, which are lacking in our Nearctic species, even 

 when possessing the second type of venation, hence the two are 

 probably not subgenerically identical. Robertson has proposed 

 the genus Microstelis, with 6". lateralis as the type, and this name 

 might well be employed as a subgeneric group for the Nearctic 

 species normally having the second recurrent nervure opposite or 

 beyond the second transverse cubital nervure. 



The subfamily Anthidiinae is composed within our limits of the 

 bees of the genera Anthidiiim and Dianthidium. Anthidium was 

 proposed by Fabricius in 1804 {Systema Piesatorum, p. 364) and 

 in 1810 Latreille designated A. manicatum (L.), the first species 

 included under the genus by Fabricius, as the type (Considerations 

 generales siir I'ordre naturel des crustaces, arachnides et insectes, 

 p. 439). Dianthidium was originally proposed by Cockerell as a 

 subgenus of Anthidium (Annals and Magazine of Natural His- 

 tory, series 7, V, pp. 412-413), but it soon became evident that 

 the group was well worthy of generic standing. Its type is 

 D. sayi, which is a name proposed by Cockerell for the Megachile 

 interrupta of Say, 1824, referred to Anthidium in 1854 by F. 

 Smith where it became a homonym of A. interruptum of Fabricius, 

 1804, and for the A. curvatum of Cresson and subsequent authors 

 up to 1907 (not A. curvatum Smith, 1854). In addition to their 

 structural differences, the nesting habits of Anthidium and Dian- 

 thidium are very different, the species of the former genus nest- 

 ing in burrows and lining the nest with cottony material, while 

 those of the latter genus make resinous nests on rocks, sides of 

 cliffs, etc. 



Heteranthidium Ckll. (Entomological Nezvs, XV, p. 292) was 



