Thus in _Eucera_ and _Melecta_ there are but five joints; in _Osmia_ and _Saropoda_, four; in _Chelostoma_ and _Cœlioxys_, three; in _Anthidium_ and _Megachile_, etc., two; and in _Epeolus_ and _Apis_ but one. In this collocation no incidental peculiarity beyond diversity is apparent, for in the first instance a parasite and a bee not parasitical are associated; and in the last, a parasite is associated with the bee which has the most elaborate economy, and the most largely developed instinct of all known insects. Nor are, in any case, those parasites associated by these means with their own sitos, or insect upon which they are parasitical. Thus encouragement attends the beginner at the very outset of his study; and the prospect of a wide field for discoveries, in many directions, lies open to him, to excite his curiosity and to stimulate his industry to the pursuit of higher aims than the mere accumulation of species. ------------------------------------------------------------------------ CHAPTER X. THE SCIENTIFIC ARRANGEMENT AND DESCRIPTION OF THE GENERA, WITH LISTS OF OUR NATIVE SPECIES AND AN ACCOUNT OF THE HABITS AND ECONOMY OF THE INSECTS, WITH INCIDENTAL OBSERVATIONS SUGGESTED BY THE SUBJECT. I NOW proceed to the treatment and description of the genera severally, and the enumeration of the species in due scientific consecutive order. The generic names adopted are those of the first describers of the genera; but the generic characters given by them could not be employed, they having been usually framed to suit special purposes. All the generic characters introduced into this work are therefore quite original, and have been made from a very careful autoptical examination of the insects themselves. The synonymy added to the lists of species is limited to the species described in Mr. Kirby’s work, where he is not the first describer, or to those of such other English works wherein the species may have been described in ignorance of its previous registration. The observations appended, wherein the habits of the insects are described, will be found to embrace discursive subjects suggested by the matter in hand, and here a dry didactic style has been purposely avoided, as in the majority of cases they record the personal experiences or notions of and hints from an old practical entomologist. CLASS INSECTA METABOLIA, _Leach_. Order =HYMENOPTERA=, _Linnæus_. DIVISION _ACULEATA_, Leach. Antennæ in male with 13 joints, in female with 12. Abdomen in male with 7 segments, in female with 6. FAMILY MELLICOLLIGERÆ (Honey collectors), _Shuck_. Subfamily 1. ANDRENIDES (Subnormal Bees), _Leach_. _Syn._ Genus MELITTA, _Kirby_. _The maxillary palpi always six-jointed._ Section 1. _With lacerate paraglossæ._