HENRY J. FRANKLIN. 185 



cell much narrowed towards the marginal, receiving the first recurrent 

 nervure about the middle ; the third cubital narrowed towards the 

 marginal, receiving the second recurrent nervure near its apex. Scu- 

 tellum semicircular, rounded off posteriorly and not projecting strongly 

 over the median segment. Hind metatarsi of the female more or less 

 strongly dilated, Hind tibiae with two apical spurs. Claws bifid. 

 Abdomen robust in form, truncate at base and convex above, pointed 

 at apex in females and rounded in males. The females provided with 

 a strong sting. 



Tables of Genera. 

 Females. 



Hind tibiae convex and well covered with hair without ; each side of 

 the apical portion of the hypopygium with a noticeable eleva- 

 tion or carina Psitliyrus. 



Hind tibise flat or concave and, for the most part, bare on their outer 

 sides, their fore and hind borders fringed with long hairs 

 forming pollen baskets ; apical ventral abdominal segment 

 without lateral elevations BonibliS. 



Males. 



Volsella and squama of genitalia membranous ; face always densely 

 covered with black pile with which there is usually no ad- 

 mixture of yellow hairs ; outer surface of hind tibiae, in most 

 species, well covered with pile throughout Psitliyrus. 



Volsella and squama of genitalia corneus ; a good share of the species 

 with face bearing a noticeable amount of yellow pile ; outer 

 surface of hind tibiae in most species more or less bare. 



Bonibus. 



Genus BOMBUS Latreille. 



Apis Linnaeus and other authors (in part) . 



Bombus Latreille, Hist. Nat. Crust, and Insect, IH, 1802, p. 385 (in 

 part) . 

 " Latreille, Hist, Nat. Fourmis, 1802, p. 436 (in part). 

 Fabricius, Syst. Piez., 1804, p. 342 (in part). 

 Bremus Panzer, Fauna Insect. German. VIII, 1805 (in part). 

 Bombus lUiger, Magaz. f. Insektenk., V, 1806, p. 158 (in part). 

 Bremus Jurine, Nouv. meth. class. Hymen. 1807, p. 259 (in part). 

 Bom.bus Leach, Brewster Edinb. Encycl., 1815, 4, Vol. 9, p. 1. 

 " Dahlbom, Bombi Scandin., 1832, p. 23, Div. I. 



Lepeletier, Ann. Soc. Ent. France, I, 1832, p. 366.. 

 " Westwood, Intr. Mod. Class. Insect. II, 1840, p. 280, 

 " Smith, Cat. Bees of Great Britain, 1855, p. 207. 



TRANS. AM. ENT. SOC, XXXVIII. (24) 



