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 continents. 



Fig. 1. Lipeurus quadrimacvlatus, 



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 straggling to take place. Had there been a common oc- 

 currence of certain genera upon gulls or petrels and upon penguins, then straggling might be 

 suspected. But these particular genera, Goniodes and Goniocotes, are not found upon gulls or 

 petrels, or upon any other marine birds except penguins. And although only one or two 

 species have been described from these last hosts, I have in my own collection other unde- 

 scribed forms taken from Australian penguins, the only parasites I have taken from these birds 

 belonging to these genera, so that the penguin habitat cannot be questioned. 



In default of any better explanation. I submit that these facts of distribution point to the 

 Sphenisciformes having an ancestral stock in common with the Tinami formes, Galli formes, 

 and Columbiformes. It would follow from this that the penguins have undergone a compara- 

 tively recent and rapid specialisation to an aquatic life, and are not such an ancient ami 

 lowdy group as they have generally been considered. A suggestion such as this might pos- 

 sibly enable the morphologist to attack the problem in a new light. It could, of course, only 

 be a suggestion. Bird phylogeny must be established upon definite morphological grounds. But 

 if a study of the parasites gave us a reasonable series of indications of relationship, it seems 

 probable that the morphologist, on a re-examination of his types, would be able to separate 

 those characters of phyletic value from those which are useless from this point of view, and 

 would be able to place our knowledge of bird relationships upon a surer footing. 



