wagtails thought it was time that their own rapacity should stop the course of these predacious insects. But to return, the female _Apathi_ then resort to the nests of the _Bombi_ whence they have issued, and lay themselves up in their winter dormitory. That this must take place speedily after impregnation is rendered almost conclusive by the fine state in which their pubescence appears in the spring, which would be tarnished did they loiter about visiting flowers previous to their return home. But the labours of the female and neuter _Bombi_ themselves are now over, and they would therefore find no store whereon to deposit their eggs. The parasitical allocation of these insects is as follows. _Apathus rupestris_ infests _Bombus lapidarius_; _A. vestalis_ the _B. terrestris_, and this forms an instance in which the parasite is not clothed in the colours of its sitos. But _A. Barbutellus_ has a wide range, for it frequents the nests of _B. pratorum_, _B. Derhamellus_, and _B. Skrimshiranus_. †† _Not parasitical._ _Collectors of pollen._ ‡ _Temporarily social._ Genus 26. BOMBUS, _Latreille_. (Plate XIV. figs. 3 and 4, and Plate XVI. figs. 1, 2, 3.) APIS ** _e_ 2, Kirby. _Gen. Char._: BODY densely hirsute. HEAD small, subglobose, not so wide as the thorax; the _vertex_ glabrous, with a longitudinal, short, deep channel, crossed in its centre by a deeper transverse one, wherein the _ocelli_ are disposed in a very slightly-curved line; _antennæ_ short, geniculated, and filiform; the _scape_ half as long as the flagellum, the first joint of which is globose, the second subclavate, the rest short and subequal, and the terminal one compressed laterally; _face_ flat, densely pubescent; _clypeus_ subtriangular, gibbous, its base truncated, and apex convexly lobated, or straight and margined; _labrum_ lunulate; _mandibles_ broad at the base, and obscurely tridentate; _cibarial apparatus_ moderate; _tongue_ twice the length of the labium, clothed with pubescence to within a brief distance of its apex, and terminating in a small knob; _paraglossæ_ about one-fourth the length of the tongue, coadunate at the base, and acuminate; _labial palpi_ three-fourths the length of the tongue, broad at the base, and tapering to the extremity of the acute apex of the second joint, which is about one-fifth the length of the first, the two terminal joints very short and articulated laterally just before the end of the second; _labium_ one-half the length of the tongue, broadest at its base, and acutely produced in the centre of its inosculation; _maxillæ_ as long as the tongue, subhastate and acuminate; _maxillary palpi_ two-jointed, short, sometimes equal, and slightly robust, or with the basal joint very robust, and its terminal joint twice as long and linear. THORAX globose, very hirsute, whence its divisions are inconspicuous; _scutellum_