PREFACEH TO VOLUME II. 
Tue chief part of the present volume is Dr. Wilson’s beautifully illustrated report 
on the Birds and Mammals, giving his personal experiences during the Expedition, 
as well as the results of subsequent study of the collections. This Expedition was 
the first to discover a nesting colony of the Emperor Penguin. 
All the other collections of vertebrates made during the Expedition are here 
reported on, with the exception of the embryos of seals and the pelagic fishes, 
which will be dealt with later. The investigation into the development of the feathers 
of the penguin raises several points of great morphological significance. The collection 
of fishes is small, but interesting. 
The discovery of two new species of Cephalodiscus, the presence of which in the 
collection was first noticed by Prot. Ray Lankester, has been made the basis of an 
important contribution to our knowledge of the small group to which it belongs. 
All the Mollusca collected by the ‘ Discovery,’ except the “‘ Pteropoda,” are reported 
on; the Brachiopoda were but poorly represented. As Dr. Calman’s reports on two 
divisions of Crustacea have been a very long time in type, it was decided to publish 
them as soon as possible. Several reports have already been printed for the third 
volume, which will probably appear early next year. 
FE. Jerrrey Bett. 
December 3, 1906. 
