128 GENERA OF HYMENOPTERA. 



workers. By some systematists the latter family is restricted to the 

 social species only. 



In the larva state all the species feed on |>ollen or honey stored up 

 by the parent, the parasitic species, cuckoo-like, consuming the food 

 provided for the legitimate inhabitant of the nest. 



In tabulating the genera belonging to this series use has been made 

 of external characters when possible, simply because they are more 

 easily seen, and although the arrangement is far from being a natural 

 one, a« will be observed by the way in which the genera of the two 

 families are intermixed in the tables, yet it will be found a nmch 

 easier mode of identification than if the more natural, though often 

 invisible characters, founded upon the modification of the mouth 

 parts, were used. These latter are generally retracted and hidden 

 in cabinet specimens, and unhess drawn out and arranged before be- 

 coming dried, are troublesome to get at, and moreover cannot be dis- 

 tinctly seen without the aid of a lens of more than ordinary power. 



From the fact that the characters separating the two families of 

 this series are taken from the form of the tongue, and that no exter- 

 nal characters have been found that will distinguish them, the genera 

 belonging to both must necessarily intermix in the following table : 



Table of Genera. 



Anterior wings with three submargiiial cells •>. 



Anterior wings with two submarginal cells 19. 



2. — Posterior tibiae without apical spurs: cj-esha' approximate above in % : 

 marginal cell very long, almost reaciung the apex of the wing; 



maxillary palpi l-jointed ; sexes 'J, 9 ^ Apis Linn. 



Posterior tibiae with apical spurs ; tip of marginal cell remote from the apex 



of the wing 3. 



3.— First recurrent nervure quite or nearly uniting with the first transvei-se- 



cubital nervure Megacilissa Smith. 



First recurrent nervure received by the second submarginal cell near its 

 middle or l)eyond the middle, rarely uniting with the second trans- 



vei-se cubital nervure 4. 



4. — BMrst discoidal cell much longer than the marginal cell 5. 



First discoidal cell not as long or scjircely longer than the marginal cell.. H. 

 .5. — Marginal cell short, not half the length of the first discoidal, and not or 

 scarcely extending beyond the apex of the third submarginal cell. 

 Scutellum bitiiberculate; maxillary jialpi 5-jointed ; claws of the four pos- 

 terior tarsi dilated ; abdomen generally with spots or interruptetl 



bands of pale,* depressed, scale-like pubescence Melecta Latr. 



Scutellum bi.spinose; maxillary palpi 6-jointed ; tarsjil claws not dilated; 



^^ abdomen without pale spots Boiubomelecta Patton. 



Marginal cell at lea.st half the length of the first discoidal, and extending 

 more or less beyond the third submarginal cell 6. 



