FOREIGN GENERA OF BEES. 103 



attention, for it is opposed to the economy of nature 

 that there should exist any without functions of essential 

 usefulness, making them important elements in her har- 

 monious order and necessary to her due course, irre- 

 spective of the instruction to be derived from the study 

 of the manifold varieties of structure, which unquestion- 

 ably point to distinguishing peculiarities of habits. 



In the true bees the division of the Dasygasters presents 

 the fewest differing generic forms : the Nudipedes and 

 Scopullpedes exhibit more numerous varieties, the pre- 

 ponderance being in favour of the pollen-collecting bees 

 (the latter), although the cuckoo bees (the Nudipedes) 

 are very abundant, and taken en masse, are certainly the 

 handsomest. If it be absolutely the case that there are 

 no parasites amongst the Andrenida, this subfamily will 

 add very largely to the exotic pollinigerous majority, 

 which thereby becomes extensively subservient to the 

 fruition of the vegetable kingdom. 



Those bees which are exclusively inter- or sub -tropical, 

 seem furnished with larger capacities for fulfilling the 

 special mission to which the family is appointed. Their 

 pollinigerous and honey-collecting organs are peculiarly 

 adapted both to the structure and luxuriance of the 

 superb vegetation of those regions, and to which they 

 seem distinctly limited. But that they are not con- 

 sidered equivalent to the entire demand of the profuse 

 bloom everywhere abounding, may be concluded from 

 the tropical range and distribution of many of our 

 northern forms. Thus, whilst the flora of those climates 

 is strictly circumscribed in its diffusion, its fauna, dis- 

 tinctly in the class of insects, and especially in the family 

 of bees, is very considerably less limited in extension. 



The exotic genera of bees which are peculiarly notice- 



