FOREIGN GENERA OF BEES. 105 



Xijlocopa. Of the habits of the former we know nothin 



o> 



but those of the latter we are intimately acquainted 

 with, through the elaborate descriptions given by Reau- 

 mur and the Rev. L. Guilding, the latter of whom made 

 his observations upon a species found in the island of St. 

 Vincent's, in the West Indies. This last genus exhibits 

 in some of its species the giants among the bees, and one 

 is especially so, a native of India, the Xylocopa laiipes, 

 which is an inch and a quarter long, and more than three 

 inches in the expansion of its black, acute wings ; and it is 

 also noticeable from the anterior tarsus in the male being 

 greatly dilated and white, the bee itself being intensely 

 black, and which in this same sex has enormous eyes 

 united at the vertex, as in the male Apis, or drone. In 

 this genus, as in many other genera of bees, there is often 

 a great discrepancy in the appearance of the sexes, they 

 being so totally dissimilar that no scientific skill has 

 hitherto been able to discover a clue for uniting toge- 

 ther correctly, by scientific process merely, the sexes of a 

 species; thence the numbers of the species in such ge- 

 nera are unduly augmented beyond their natural limits, 

 from the fact of observation having neglected to associate 

 the legitimate partners. 



In some of our native genera this same difficulty 

 existed, which, however, is gradually diminishing as the 

 authentic sexes are slowly discovered. 



Exotic bees exhibit also a peculiarity I had occasion 

 to observe before, in reference to our own bees, amounting 

 perhaps to a law, viz the more highly-coloured condition 

 of the parasite, for we find all the parasitical bees of those 

 latitudes, usually gorgeously arrayed in metallic splen- 

 dour, as instanced in Aglae, Mesonychia, Mesocheira, 

 etc., and Melissoda (my Ischnocera, in Lardner), is re- 



