SEALS. 215 
remarkable degree. Such marked diversity of teeth and skull cannot 
be meaningless, yet, except in the case of Ogmorhinus, no observer 
has as yet laid special stress upon any corresponding divergences 
of habits or life-history. 
Owing to the unfortunate death of Mr. Hansen, and the loss of 
his zoological notes, the Southern Cross expedition has not had for 
one of its results any striking enrichment of our knowledge of the 
habits and life-history of the Antarctic Phocide, No MS. of any 
sort dealing with this subject has been placed in my hands, but 
Mr. Borchgrevink occasionally mentions seals in a paper read before 
the Royal Geographical Society. These, wherever they deal with 
a particular species, are alluded to under the heading of that 
species. The more important general notes tell us that seals were 
scarce in the pack, increasing in numbers, however, as the ship pro- 
ceeded southwards. As to the moult of the seals Mr. Borchgre- 
vink remarks (p. 382), “The moulting starts on the back, in a 
straight line from nose to tail.” . 
As regards migratory movements, if any, on the part of the seals, 
we have practically no evidence of their existence. Mr. Borchgre- 
vink’s remarks certainly do not lend any support to the existence of 
any extensive migration. Any observations bearing on this subject 
would be of much value. 
Dentition.—The teeth of the Phocide are remarkable for the 
extreme variety which they display in the various genera. In most 
cases dental characters present the most distinct features of animals 
which are externally very similar. In the skin, as seen in museums, 
Leptonychotes and Lobodon are, but for their colour, difficult to sepa- 
rate; nothing could be more distinct than the forms of their respec- 
tive teeth. It is evident that, whereas the needs of existence do not 
tend towards any very great variety of bodily shape, the food of the 
Phocide, or the method of securing it, may be so varied as to have 
induced the evolution of so many quite distinct types of dentition, 
the production of which postulates great plasticity of the teeth. The 
result is that the Phocide have already, by their teeth, shown them- 
selves to be on the road to division into groups corresponding with 
some of those of the terrestrial mammalia. Thus, while Oymorhinus, 
with its sinuous body and saw-like teeth, represents the most specialised 
form of Pinniped carnivore on a large scale, Ommatophoca, Erignathus 
and Cystophora represent more general feeders, while the smaller 
carnivora are respresented by Phoca hispida and P. vitulina—resem- 
blances which seem to suggest all sorts of possibilities in dual evolu- 
