The greater number of our species were described by Maskell in the “Transactions of the New Zealand Institute between the years 1878–1898,” in which period he added over 100 new species to our list: Green (Pro. Linn. Soc. N.S.W. 1900) has described some others; and in the same Journal (1882–1898) I dealt with the gall-making coccids belonging to the sub-family BRACHYSCELINAE. In 1894 Maskell issued a “Synoptical List of the Coccidae reported from Australia and the Pacific Islands,” in which 180 species were credited to Australia. To this Maskell added later a number of new forms; and Fuller others from Western Australia (Trans. Ent. Soc. London 1899). In Mrs. Fernald’s “Catalogue of the Coccidae of the World” (Hatch Experiment Station Bulletin 88, 1903) over 328 species are listed, from this country, but there are a considerable number of doubtful species among them. The COCCIDAE have been divided into a number of sub-families: I follow Green (Coccidae of Ceylon, 1896), though Mrs. Fernald in following Cockerell reverses the families and starts with the mealy bugs; I also retain most of the well-known generic names unless there is a very valid reason for discarding them, which does not appear to be the case in many of Cockerell’s amendments. The Sub-family DIASPINAE are known as armoured scales and embrace most of the forms which cover themselves with stout horny shields (puparia). When adult the female is almost legless, with rudimentary antennae, and incapable of movement. The members of the Genus _Aspidiotus_ form round scales, and among them are some of our worst orchard pests. The introduced species _Aspidiotus auranti_, the Red scale of citrus trees, is now found on many garden shrubs. The puparium of the adult female is dull reddish yellow with the centre lighter coloured, and the twigs, leaves and fruit of neglected trees are often covered with these scales in all stages of growth. _A. perniciosus_, the notorious San José Scale, that attacks deciduous fruit-trees in the same manner, is a dull brown circular scale; its original home is somewhat doubtful, and though it was first recorded as a pest in California, is said to have come from China. The scales are much darker than those of the red scale, and infest the branches and twigs so thickly that they destroy the bark, and whenever they attach themselves to the fruit produce a red spot. _A. hederi_ (better known under the name of _A. nerii_), is a pure white scale with a yellow centre; it has a world-wide range, and its range extends far out into our western scrubs, sometimes covering the whole of a large tree. _A. rossi_ is a very distinct, round, black scale, partial to _Euonymus_ in the garden, and to grass trees in the bush. _A. ficus_ is often known as the “Round Scale” from its size and regular shape; it is deep chocolate brown in colour, common upon palms, and is sometimes found upon oranges coming from the Pacific Islands.