His genus Apis he also divides into two sections, * and * *; the first is subdivided into two families, a and b (our genera Panurgus and Nomada); and the second is divided into five subsections, a, b, c, d, e; a and b constitute families (our genera Melecta and Epeolus). The subsection c is divided into two parts, 1 and 2, the first containing the two divisions α and β, each comprising a family (our genera Cœlioxys and Stelis); and the second is divided into the four families, α, β, γ, δ, (α being the modern Megachile; β, Anthidium; γ, Chelostoma and Heriades conjunctively, and δ is our Osmia). The subsection d has two subdivisions, 1 and 2, the first being a family (our Eucera); and the second is divided into the two families α and β (α comprising our Saropoda, Anthophora, and Ceratina), and the family β, consisting of the genus Xylocopa, then supposed to be indigenous, but whose native occurrence has not been substantiated.
The fifth subsection, e, is split into two divisions, 1 and 2, each containing a family (1 is our Apis, and 2, our Bombus).
In this last of his families Mr. Kirby had already noticed, with the same sagacity with which he had previously conjectured the cuckoo-like habits of some of the solitary bees, the distinctive structure of some of the species, which incapacitated them from providing the sustenance of their own young, and which thus reduced them to the same category; but he left the idea in its supposititious condition, being too modest to use it as a mark of separation, but which Newman, on our side of the Channel, and St. Fargeau on the other side, subsequently, and both nearly about the same time, but with the advantage in favour of Newman, distinguished, and separated generically, respectively by the names of Apathus and Psithyrus; the former, having the priority, is adopted, according to the rights of precedence in nomenclature.
The above description of Mr. Kirby’s system will perhaps be difficult to understand, unless I append the naked scheme itself, which is as follows:—
MELITTA.
Mr. Kirby could scarcely have considered that there were more than two series of equivalents in this scheme, the first being the great division into the two genera; and the second, the final division, where his analysis terminated in his families, which, with some further slight subdivision, as shown above, constitute our present genera. The synthetical combinations which the arrangement presents, as we ascend from his families, result from an almost arbitrary selection of characters and certainly are not equivalents. The whole method is very perplexing; for, to cite an insect for the purpose of making a communication, it would have to be preceded by its whole array of subdivisions. Thus Megachile Willughbiella, which is now so compendiously noticed by the binomial system, would have to be quoted as Apis * * c, 2, a, Willughbiella, and so with the rest.
Although I have strongly applauded the ‘Monographia Apum Angliæ,’ as an excellent treatise wherever I have had an opportunity, the praise is to be applied to the correct care with which both the family descriptions and the specific descriptions are elaborated; whilst Mr. Kirby’s timidity in fearing to depart from the course of his masters, Linnæus and Fabricius, by establishing a multitude of genera unrecognized by their authority, although every one of his families is pertinently a well-constituted genus, is much to be deplored. He has thus lost the fame of naming the offspring, of which, although legitimately the parent, he was not the sponsor. But he has won the higher renown, as I have elsewhere remarked, of his work being a canon of entomological perfection.
Notwithstanding that this very elaborate, and, to some extent, artificial method is based upon a plurality of characters, and apparently upon such as most readily presented themselves to substantiate the feasibility of subdivision indicated by habit, it is very remarkable in having brought the series into more satisfactory sequence than that presented by Latreille and his modifiers. Panurgus here holds its permanent post as the connecting link between the Apidæ and Andrenidæ, pointed out by nature in its close resemblance to Dasypoda. But this genus, however, establishes for itself a stronger affinity to the Apidæ, exclusively of that presented by the folding of the tongue in repose, in its presenting immediately the large development of the labial palpi which is peculiarly characteristic of this subfamily.
All the cuckoo-bees then follow in order; these are succeeded by the true Dasygasters; after which come Latreille’s Scopulipedes; and the series is wound up by Apis and Bombus.