The Flying Squirrel of North America (_Sciuropterus volucella_) is closely copied by the Flying Phalanger (_Petaurus breviceps_) of Australia. It will be readily seen that in no one of these cases can the likeness be of utility to either the “model” or the “copy.” False Batesian Mimicry among Birds There are many instances of this phenomenon among birds. The New Zealand Cuckoo (_Urodynamis tritensis_) shows a far closer resemblance to the American Sparrow-hawk (_Accipiter cooperi_) than to any New Zealand hawk, and in fact closely mimics this quite alien bird. The stormy petrel, a purely oceanic bird, closely resembles in size, colour, and style of flight the Indian Swift (_Cypselus affinis_), a purely inland creature; both are sooty black, with a conspicuous white patch on the lower back. The Pied Babbling Thrush (_Crateropus bicolor_) of Africa is singularly like the Pied Myna (_Græulipica melanoptera_) of Java, both being of about the same size, with white body and black wings and tail quills. This, we may add, is a very unusual colouration among small birds. The black-headed Oriole (_Oriolus melanocephalus_) of India is very similar in appearance to the common Troupial (_Icterus vulgaris_) of Brazil; indeed, the troupials, a purely American group, are so like the old world orioles in colour that they usurp their name in America. The little insectivorous Iora (_Ægithina tiphia_) of India strongly resembles in size and colour a Siskin (_Chrysomitris colambiana_) from South America, the males in both being black above and yellow below, while in the females the black is replaced by olive-green. Another Indian babbler (_Cephalopyrus flammiceps_), yellowish-green, with orange forehead, is closely copied by, or copies, the well-known Brazilian Saffron-finch (_Sycalis flaveola_). In Fergusson Island, near New Guinea, there is a ground pigeon (_Otidiphaps insularis_) which is black with chestnut wings, like several of the powerful ground cuckoos of the genus _Centropus_, but no species of these cuckoos so coloured appears to inhabit the island. In Africa there is a tit (_Parus leucopterus_) which has the same very unusual colouration as an East-Indian bulbul (_Micropus melanoleucus_), both being black with a white patch on the wing-coverts. These two birds are about the same size. As showing the purely coincidental character of such resemblances, we may mention that this same rare pattern occurs again in our Black Guillemot (_Uria grylle_) and in the Muscovy Duck (_Cairina moschata_). We have already quoted Gadow (p. 198) on “false mimicry” among snakes. He also gives, on p. 110 of _Through Southern Mexico_, an example of this phenomenon among amphibia. It is, he writes, “impossible to distinguish certain green tree-frogs of the African genus _Rappia_ from a _Hyla_, unless we cut them open. If they lived side by side, which they do not, this close resemblance would be extolled as an example of mimicry.”