136 GENERA OP' HYMENOPTERA. 



genera, togethei* witli Emplior, Eniechnia, Habropoda, Anihophora 

 and Cli^odon, have been made the subject of an interesting paper by 

 Mr. Patton, entitled, "Generic Arrangement of the Bees allied to 

 Meli.^mdes and Anihophora (Bull. v. U. 8. Geo. Surv. 1879)," in wliicli 

 the characters are given at length. 



The genus Xylocopa, commonly known as " Carpenter Bees," from 

 their habit of boring tunnels in posts, rails, etc., in which to nidificate, 

 contain some of the largest species of the family. 



The genera Bomhm and Apis are too well known to need any ref- 

 erence here to their structural chai'acters. They differ from all other 

 l)ees in their social habit.s, being composed of males, females and 

 workers. The species of Bombufi, or " humble-bees" construct their 

 nests generally under ground in meadows, pastures, etc., and form 

 societies of more or less extent ; their union, however, lasts only until 

 the cold weather destroys all Imt a few impregnated fenuiles, who 

 survive to found fresh colonies the following sjiring. 



Apatkus is a parasitic genus of bees which inhabit the nests of the 

 Bombi. " What office," says Smith, " these bees ])erf()rm in the 

 economy of the nest has not been discovered ; they live on the most 

 friendly terms with the industrious part of the conununity, and it is 

 probable that upon them devolves some important office, the nature 

 of which it would I)e very interesting to discover." The genus dif- 

 fers from Bombns principally in the absence of the corbicula on the 

 posterior legs of the 9 , the tibite in both sexes being outwardly con- 

 vex and densely clothed with short hairs. 



The genus Apk contains the common "Hive-Bee," melUfica, which 

 is C()smo})olitan, and upon which volumes have been written, yet 

 many interesting points in their economy still remain undetermined. 

 " We can scarcely estimate," says Smith " tlie value the i)roducts of 

 tlie iiive must have been to man in ancient times; but when we re- 

 member that honey must have formed the staple commodity wliich 

 our forefathers applied to all the uses for which sugar is now sub- 

 stituted, and at the same time recollect even the present value of the 

 wax, we shall arrive at a considerable estimate of the beneffts de- 

 rived from these industrious insects." 



