AMERICAN HYMENOPTERA. 289 



THE BEES OF NEW MEXICO. 



BY T. D. A. COCKERELL. 



More species of bees are known from New Mexico than from any 

 other State or Territory. This is not to be explained merely as the 

 result of diligent collecting, — indeed the work done does not nearly 

 cover the ground, and whole regions, and doubtless dozens of species, 

 remain unknown. The vast area — difficult to appreciate unless one 

 has travelled over it — and the combination of desert, mountain and 

 valley afford such a variety of conditions that we have in fact not 

 one fauna, but several ; and any statements about New Mexico, with- 

 out further details, become comparatively meaningless. If proof is 

 wanted, that in spite of all that has been done, abundant riches 

 remain, it is afforded by the results of the xVcademy of Natural Sci- 

 ences expedition to Alamogordo and the Sacramento Mountains 

 several years ago. I went over most of the bees collected by Mr. 

 Viereck, when he visited me at Las Vegas, and was interested to 

 see many new species, even several of the genus Perdita, which had 

 been my especial study. Unfortunately, much of this material still 

 remains undescribed or unreported, and I am unable to incorporate 

 all the important data it would afford. There is no doubt that bees, 

 from the number of species, the ease with which they are collected, 

 and the restricted distribution of many, afford excellent material 

 for defining zoological regions and life zones. That they have not , 

 been used to any extent for such purposes must be explained by the 

 inadequacy of existing collections and records, and especially the 

 difficulty of determining the species. The difficulties of determina- 

 tion are not especially the fault of those who have described these 

 insects, but necessarily result from the extraordinary wealth of still 

 undescribed species. An insect may appear to be so and-so, but it 

 is necessary to examine it with great care, as it may present some 

 peculiarity, in some part of its anatomy, showing it to be a hitherto 

 unknown form. Thus it will not be safe to trust to supei'ficial ap- 

 pearances until the fauna has been much more thoroughly worked up. 



In the following enumeration of New Mexico bees, I have divided 

 the species of each genus into groups according to their zonal distri- 



TEANS. AM. ENT. SOC. XXXII. (37) OCI OBEK. 1900. 



