240 THE VOYAGE OF H.M.S. CHALLENGER. 



Of the so-called species associated together by ornitliologists under the genus 

 Eudy2^tes, I have examined two, Eudyptes chrysocome and Eudyptes chrysolophus. Of 

 these two species, Eudyi^tes chrysocome presents three varieties, which are met with at the 

 island of Tristan d'Acunha, the Falkland Isles, and Kerguelen Island respectively. 

 That Eudyptes chrysolophus ought to be regarded as a species distinct from Eudypjtes 

 chrysocome is not doubted by any ornithologist, but an examination of the entire 

 anatomy both of Eudyptes chrysolophus and oi Eudyjotes chrysocome appears to me rather 

 to lend support to the view that they are simply two well-marked varieties of one and the 

 same species of EudyjJtes. The decision of this point must depend on the relative value 

 attached by various ornithologists to difference in size and similarity of anatomical 

 structure as elements in the determination of species as distinguished from variety. 



The genus Aptenodytes includes the two species which I have examined, — Apteno- 

 dytes longirostris, and Ap>tenodytes tceniatus. The last named has been accepted by ornitho- 

 logists as a type of another genus, Pygosceles ; but I see no reason on anatomical grounds 

 why it should not be included along with Aptenodytes longirostris as another species of 

 one and the same genus. 



I regret that I have not had an opportunity of dissecting a specimen belonging to 

 the genus Dasyramphxis of Gray, and am therefore unable to refer that genus to its 

 proper place with reference to the other birds which I have examined. 



Lastly, in respect of their affinities the Penguins appear to be more closely allied to 

 the Palmipede than to any other group of birds, but the numerous important deviations 

 which they present from every one of the various groups included within that very hetero- 

 geneous assemblage appear to show that the Spheniscida^ must have diverged at an early 

 period from the primitive a\'ian stem from which both groups were derived, and the con- 

 necting links having been lost, it seems at present hopeless to attempt to establish 

 the exact affinities of the Penguins to other birds At first sight, indeed, it appears that 

 the nearest allies of the so-called wingless birds of the southern are to be found in the 

 wingless birds of the northern hemisphere, but the researches of Prof. Owen^ on the 

 osteology of the Great Auk {Aha impennis), abundantly show that the two groups 

 have but little in common. We are compelled therefore to postpone the accurate determin- 

 ation of the affinities of the Spheniscidaj till the progress of Palaeontology shall have 

 made us acquainted with the intermediate forms which connect the Spheniscidse with the 

 primitive avian stem from which both they and the other Palmipedes were originally 

 derived. 



1 Description of the skeleton of the Great Auk or Garfowl {Alca impennis). Trans. Zool. Soc, vol v. p. 317. 



