Miscellaneous. 71 
Those which have taken up their abode at the Cape of Good Hope 
have never been able to come up along the eastern coast of the con- 
tinent, on account of the Mozambique current, which drove them 
back incessantly towards the south. It is this that explains why 
the eared seals are wanting in all the Atlantic Ocean north of the 
Falkland Islands, as well as in the whole western region of the 
Indian Ocean. Thus there remains only the eastern part of this 
latter ocean ; and it is evidently by this route that the migration 
under consideration was accomplished. Having arrived, as already 
stated, on the southern shores of Australia, the Otaries have come 
up gradually on the western coast of that continent, which they 
still inhabit at the present day. In the north they have arrived as 
far as Melville Island, off the coasts of Port Essington, where at 
least two species of this family are to be found. 
We know that a secondary current, the direction of which is de- 
termined by that of the monsoon, puts the Indian Ocean in commu- 
nication with the Chinese Sea. From April until October, exactly at 
the time when the eared seals come up towards the north, this current 
is directed towards the north-east and flows into the ereat basin of 
the Pacific. This current must have singularly facilitated the migra- 
tions of the Otaries, which have been performed through the 
passages of the Molucca Sea, or by the much broader and deeper. 
course of the Straits of Macassar. Once in the Chinese Sea, these 
animals gained the coast of Japan; thence, with the help of the 
great current of Tessan (the Kur-Sivo, or “black river,’ of the 
Japanese), they make the tour of the North Pacific Ocean, following 
the shores of Kamtschatka, of the Aleutian Islands, and North 
America, arriving finally at the south of California, which is the 
extreme limit of this vast circuit. 
The proof of this migration is furnished us by the genus Zalophus, 
which still occurs on both sides of the equator—namely at Melville 
Island, on the coasts of Japan, on those of California, and through- 
out the northern part of the Pacific Ocean. 
Considerations of the same kind may apply to the dispersion of 
the true seals, which are almost exclusively quartered in the northern 
hemisphere. 
Thus a species of the genus Pelagius (or Monachus) has recently 
been met with in the West-Indian Sea. Now hitherto this genus 
has been considered peculiar to the Mediterranean ; but we know 
that the monk-seal (Pelagius monachus), the only species formerly 
known, has passed through the Straits of Gibraltar ; it occurs on the 
north-west coast of Africa, and as far as Madeira and the Canary 
Islands. It is probable that some individuals of this species, having 
been seized on these coasts by the equatorial current which com- 
pletes the circuit of the Gulf-stream, have been carried to the west 
as far as the West-Indian Sea, where they have constituted a new 
form (Pelagius tropicalis, Gill). 
The geographical distribution of the sea-elephants (Macrorhinus), 
is more difficult to understand. It is the only true seal (comparable 
in this respect to Zalophus) which is found equally on both sides of 
