"In the two families, which constitute this highly interesting group, is fortunately preserved a type of _Lepidoptera_ whose existence could never have been inferred from a study of other forms. Without a knowledge of these two families the true origin of the order could never have been more than a matter of more or less probable conjecture. The _Micropterygidæ_ are the primeval ancestors of all the Lepidoptera, indicating their origin from the _Trichoptera_ so nearly that one or two more discoveries might make it hard to draw any line of demarcation. The _Hepialidæ_ are an offshoot from the _Micropterygidæ_ (with considerable extinction of intermediate forms), constituting a separate line of development quite unconnected with any other _Lepidoptera_; if, as is possible, this separate stem may have ever given rise to other branches forming distinct families, all trace of their existence seems to have been lost. "Imago with fore-wings and hind-wings more or less semi-oval, termen and dorsum forming a nearly uniform curve. "Larva with few hairs, with 10 to 16 prolegs, or apodal, living concealed. "Pupa in _Hepialidæ_ with segments 7 to 11 and in male 12, in _Micropterygidæ_ with all segments free."--(Meyrick.) In this work the _Hepialidæ_ alone are dealt with, the _Micropterygidæ_ being reserved {128}for a future work. It may, however, again be mentioned that the last-named family contains amongst its New Zealand representatives _Palæomicra chalcophanes_, a species which more closely approximates in structure to a Neuropterous insect than does any other member of the _Lepidoptera_. This insect is consequently regarded by Mr. Meyrick as the most ancient species of the order yet known. The survival of _Palæomicra_ in New Zealand is quite in accord with the existence of such forms as _Apteryx_ and _Dinornis_ amongst the birds, the tuatara lizard (_Sphenodon_) amongst reptiles, and _Peripatus_ amongst _Myriapoda_, archaic forms which have been preserved in this country through its long isolation from continental areas, and the resulting absence of more recent competing forms. Family 1.--HEPIALIDÆ. "Head rough. Ocelli absent. Tongue obsolete. Maxillary palpi obsolete. Tibiæ without spurs. Fore-wings with all main veins and costa connected by bars near base, 1_b_ furcate, forked parting vein strong." (Plate I., figs. 22, 23, 24, 28, 29.)