. The Australian zoologist. Zoology; Zoology; Zoology. 10 THE MALLOPHAGA AS A POSSIBLE CLDE TO BIRD PHYLOGENY. the adult increases in extent and becomes folded on itself in a remarkable manner, forming a V-shaped cleft, the relation of which is again more easily seen from the figure. It is hardly possible to come to any other conclusion than that these three species have been derived from a common ancestor. And we find them on hosts which admittedly have had a common origin, and which are now widely separated upon three distinct Fig. 1. Lipeurusquadrimacvlatus, Fig. 2. Degeeriella
. The Australian zoologist. Zoology; Zoology; Zoology. 10 THE MALLOPHAGA AS A POSSIBLE CLDE TO BIRD PHYLOGENY. the adult increases in extent and becomes folded on itself in a remarkable manner, forming a V-shaped cleft, the relation of which is again more easily seen from the figure. It is hardly possible to come to any other conclusion than that these three species have been derived from a common ancestor. And we find them on hosts which admittedly have had a common origin, and which are now widely separated upon three distinct Fig. 1. Lipeurusquadrimacvlatus, Fig. 2. Degeeriella asymmetnca. Fig 3. Lipeurus asymmeiricus—nfter Puiget. Next we may profitably expand the facts given by Kellogg in the paragraph last quoted p. 7). Upon tinamous and gallinaceous birds, two genera, Goniodes and Goniocotes are most commonly represented. We also find these two genera commonly upon pigeons; and a species of Goniocotes has been found upon Opisthocomus. The four bird groups here mentioned are, by some systematists, considered as closely related, and this relation is definitely supported by the distribution of parasites. But one more order of birds is concerned in the distribution of these two genera of parasites, and that is the Sphenisciformes, a fact that is noted without comment by Kellogg (1913, p. 141). No bird systematist has ever suggested any possible relation between the penguins and any of the other four bird-groups mentioned. Yet two mallo- phagan genera, characteristic of and otherwise confined to these four groups, are also found upon penguins. If the hypothesis that the five groups had origin in common be not admitted, how is the occurrence of these particular parasites on penguins to be explained? Penguins are marine, the other four groups terrestrial. I can scarcely conceive any circumstance by which pen- guins, with their Antarctic marine distribution, could come into sufficiently close relation with any of these other birds to allow of direct st
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