rich yellow; when it grows old, especially the male, exchanges these brilliant colours for a cinereous hue, which circumstance misled Fabricius to give it as a distinct species, under the name of A. Senilis. But not only yellow and red, but even black and white hairs are apt to change their colours through age. All these circumstances make it a matter of some importance to be able to distinguish a recent insect from one that has been long disclosed. This may often be done by inspecting the state of its wings, for in the latter, especially in males, they are usually lacerate at the apex; the body, too, has frequently a good deal of its hair rubbed off. It will not be without use to know into what the predominant colours fade; yellow will usually first turn pale, and then cinereous; red will turn through tawny to yellow, and sometimes to cinereous; white will turn to pale, and sometimes to tawny; and black will now and then turn white. But this is not all the difficulty with which the describer of the Bombinatrices has to struggle; the males in general resemble the females sufficiently to be known as such; but there are several so unlike them as to be easily mistaken for different species; and I am by no means certain that I have not, in more instances than one, described the sexes under different names. Till all can be traced to their nidi, this is not easily to be avoided."
We shall now proceed to give examples of the two genera Bombus and Apatlius.
