Several other species probably exist, with which I have not happened to meet.

The principal distinctions between Memythrus and Ægeria are, that the antennæ in the former are not longer than the thorax; in the latter they are much longer; in the males of the former genus they are decidedly pectinated, in those of the latter but obscurely ciliated; in the former the anterior wings are always opaque, in the latter always hyaline.

Natural Divisions to which the Sphinx Vespiformis
of Linnæus is referable.

First Primary Group ANIMALIA.
First Kingdom ANNULOSA.
Central Sub-kingdom INSECTA.
First Class LEPIDOPTERA.
Central Sub-class PHALÆNA.
Second Natural Order COSSI.
Second Family ÆGERIIDÆ.
Second Genus MEMYTHRUS.
First Species VESPIFORMIS.

FINIS.

R. CLAY, PRINTER, BREAD-STREET-HILL.

DIRECTIONS FOR PLACING THE DIAGRAMS.

1. The Classes of Insecta to face page 21.

2. The Sub-classes of Lepidoptera to face page 31.

3. The Natural Order of Cossi to face page 52.