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



1. Eudyptes chrysocome, from Tristan d'Acunha/ 



2. chrysocome, from the Falkland Islands. 



3. chrysocome, from Kerguelen Island. 



4. chrysolophus, from Kerguelen Island. 



5. Sphenisciis demersus, from the Cape of Good Hope. 



6. magellanicus, from the Falkland Islands. 



7. mendicidus, from the Galapagos Islands. 



8. minor, from Australia. 



9. Pygosceles tceniatus, from Kerguelen Island. 



10. Aptenodytes longirostris, from Kerguelen Island, 

 besides heads, with the soft parts attached, of nearly every one of these species. 



In drawing up this Report two courses were open to me. Either I might confine 

 myself to a simple enumeration of the distinctive anatomical features of the Penguins as 

 compared with those of other birds, or, with the expenditure of considerably more time and 

 labour, I might give an exhaustive account of the anatomy of every member of the 

 group which was placed in my hands. The adoption of the first plan would certainly have 

 led to the production of a more readable memoir, and one adapted to the requirements of 

 those whose object is to arrive at cut and diy conclusions, without the labour of minute 

 investigation. 



On the other hand, it appeared, in view of the difiiculty of procuring fresh specimens 

 of so many species of Penguin, that it would be well to make the most of the material at 

 my command. To accomplish this, it would be necessary to carry out an exhaustive 

 anatomical examination of every species, and to compare the results obtained from the 

 dissection of one with those obtained from the dissection of all. If this plan were adopted, 

 I might hope to put on record a complete description of the anatomy of every species at 

 my disposal, and thus exhaust the subject so far as these were concerned, leaving it to 

 other anatomists to supplement my observations by the examination of species, examples 

 of which I did not possess. 



After due consideration I adopted the latter course, and in following it out have 

 selected Eudyptes chrysocome from Tristan d'Acunha as a standard with the anatomy of 

 which to compare that of other species. In every section I have in the first place 

 described the anatomy of that species, and thereafter appended the variations met 

 with in such others as I have had an opportunity of examining. In those cases in 

 which no variations are reported, it will be understood that such did not exist, and 

 that the anatomy of these forms is identical with that of the species selected as a 

 standard. In every instance I dissected the birds systematically, beginning with the 

 bones and ending with the nerves, and in every instance I have been careful to institute a 



' Professor Watson had for the purposes of this investigation : one adult specimen of Spiieniicus minor, presented 

 to the Expedition at Sydney by Dr. George Bonnet ; two adult specimers of Sph.;niscus mcndiculus, presented by 

 Professor Alexander Agassiz, and four or five adult specimens of each of the other species. — J. M. 



