HENRY J. FRANKLIN. 227 



no well developed stigma. Three closed cubital cells are 

 present and they are of nearly equal size. They lie between 

 the costal cell, the weak stigma and the radial cell in front 

 and the first and third discoidal and second apical cells be- 

 hind, the vein between these last and the cubital cells being 

 the cubital vein. A fourth, weakly developed, cubital cell is 

 present on the distal side of the third and is open externally. 

 The veins which separate the cubital cells from each other 

 are the transverse-cubital veins. The first cubital cell is widest 

 in the middle and is pointed at each end. It is, as a rule 

 slightly wider, from front to rear, in Psithyrus than it is in 

 Bombus. It is faintly divided in the middle by an apparently 

 rudimentary and usually incomplete veinlet. The second 

 cubital cell is bordered, in front, in part by the radial cell 

 and in part by the first cubital. It comes to a point imme- 

 diately behind the middle of the latter. The second trans- 

 verse-cubital vein is nearly straight, while the third is strongly 

 outcurved. The radial cell reaches considerably beyond the 

 third cubital.' Two of the three cells, immediately behind 

 the cubitals, are closed and are termed the first and third 

 discoidal cells, while toward the tip of the wing from the last 

 named is the unclosed second apical cell, which lies posterior 

 to the outer portion of the third cubital cell. Separating the 

 first and third discoidal cells and the second apical cell are 

 two recurrent veins, the first of which arises posteriorly from 

 the anterior outer angle of the second discoidal cell, which 

 lies posterior to the first discoidal cell, the second recurrent 

 vein arising from the sub-discoidal vein. The first recurrent 

 vein joins the cubital opposite the middle of the second cubi- 

 tal cell. The second recurrent vein joins the cubital at a point 

 somewhat proximad of the apex of the third cubital cell. 

 Behind the third discoidal cell is the first apical cell, the vein 

 that separates them being the sub-discoidal. The vein sepa- 

 rating the first and second discoidal cells is known as the dis- 

 coidal vein. The anterior-basal cell is very long and narrow 

 and is called the costal cell. It is separated from the very 

 long, but broader, 7nedian cell, which lies immediately behind 

 it, by the stib-costal Yein. With the possible exception of the 



TRANS. AM. ENT. SOC, XXXVIII. 



