the fore wings separate, and the median spurs of the posterior tibiae usually present, whilst the other has always two or more veins stalked, and the said spurs always absent, there can be no doubt that the Hesperiadæ are the most ancestral family. Their very simple neuration closely resembles that of the Thyrididæ, but is not found elsewhere in the higher groups, and there is no discordance in other structural characters; moreover, the tendency to show pale semi-hyaline spots in the fore wings, and the development of specific colour-characters on the lower surface of the hind wings, are marked points of superficial resemblance. Similarly knobbed antennae occurring in the higher Caradrinina (Agaristidæ) have been thought to indicate relationship to the Papilionina; but there the frenulum is always strong and persistent, and the required simple type of neuration is never found. Hence we must suppose that the Thyrididæ are the true starting-point of the group.
The Lasiocampina comprise five families of no great extent altogether. In these the frenulum either is or tends to be absent, and vein 8 of the hind wings is frequently approximated to 7 beyond the cell, the group being always separable from the Caradrinina by one or other of these characters. In the Pterothysanidæ, Lasiocampidæ, and Endromididæ the frenulum is constantly absent; in the Drepanidæ and Callidulidæ it is sometimes present, though tending towards obsolescence, and these two families, which are apparently collateral developments, must be the more primitive. They approach the Thyrididæ, and the Callidulidæ also appear to show near collateral relationship to the Papilionina, for which, except that the antennae are not knobbed, they might sometimes be mistaken even by an expert.
The Notodontina include all those families of the higher Lepidoptera in which vein 5 of the fore wings, instead of being approximated at its origin to 4, is parallel with it, or even sometimes more approximated to 6, thus appearing to form an independent vein from the cell, instead of a branch of the vein which forms the lower margin of the cell. There is no reason to suspect that this modification has arisen more than once, the whole of these families agreeing well together in all other respects. The Eupterotidæ, mostly large insects which, both in the imago and larva states, have considerable relationship to the Lasiocampidæ,
