food-plant, conditions of life, are in this case ignored. Again, we all know how deceptive a thing colour is: what is green to one man may be blue or red to another. Ornithologists and lepidopterists have invented thousands of new “species” on account of some different colour in a feather or in a wing-spot. But many cases are known in Coccid study where, even on the same twig, amongst perhaps a hundred individuals, five different “species” could be so made because there may be five variations in colour. Again, in the case of climate and food-plant: if we were to imagine that an insect in a tropical country on, say, a palm, must necessarily be for that reason a different species from one in a temperate country on a Fagus, it would be the simplest thing in the world to bring up the number of Coccid species to that of the Hymenoptera, ransacking every dictionary in every language to find names for them. A friend of mine once wrote that he could not agree to make two Planchonice identical “because they lived on such widely-separated orders of plants as Coronilla and Bambusa.” But there are dozens of Coccids which are multivorous if not omnivorous: for example—Aspidiotus nerii, A. aurantii, Mytilaspis pomorum, Ctenochiton viridis, Lecanium hesperidum, Planchonia fimbriata, several Dactylopii, Icerya purchasi, &c. You cannot predicate that an insect living on one plant will not live equally well on another, or in another locality. Taking, therefore, these four points—size, colour, locality or climate, and food-plant—I would very seriously deprecate the notion that any of them (I will go so far as to say that all of them) should be sufficient to induce the erection of a new species. Convenience demands that they should be all mentioned in a description, as a guide to other students or as information to the public, so that anybody could know where at least to search for particular insects. Beyond that I look on them as of little or no value.

The following pages contain notes concerning many species already reported from various parts of the world, and also descriptions of more than twenty insects which, after full consideration, seem to be new. Some, such as the Australian form of Eriococcus buxi, or the Sandwich Island form of Chionaspis biclavis, I have set down as merely varieties of the original types. The others, although seeming to be quite distinct, do not present such extraordinary and interesting features as those reported in my former papers. But the discovery in Australia of representatives of the genus Ctenochiton (hitherto confined to New Zealand) seems to be not entirely unimportant in its bearing on the distribution of animal forms and the connection between the two countries.

With regard to Ceronema, the new genus which I am here proposing to establish, it may be remarked that, whilst the