MUSEUM OF COMPARATIVE ZOOLOGY, 75 
the Fishes, Crustacea, Worms, Mollusks, Echinoderms, and Polyps, we 
brought up familiar West Indian types or east coast forms, together 
with quite a number of forms whose wide geographical distribution was 
already known, and is now extended to the Eastern Pacific. This was 
naturally to be expected from the fact that the district we explored 
is practically a new field, nothing having been done except what the 
& Albatross” herself has accomplished along the west coast of North 
and South America, The “Challenger,” as will be remembered, came 
from Japan to the Sandwich Islands, and from there south across to 
Juan Fernandez, leaving, as it were, a huge field of which we attacked 
the middle wedge. As far as we can judge at present, it seems very 
evident that, even in deep water, there is on the west coast of Central 
America a considerable fauna which finds its parallel in the West Indies, 
and recalls later Cretaceous times, when the Caribbean Sea was practi- 
cally a bay of the Pacific, —a deep-sea fauna showing relationship 
on the one side to Atlantic and West Indian types, and on the 
other pointing to the eastward extension of western Pacific types of wide 
geographical range, which mix with the strictly deep-sea Panamic ones. 
The western and eastern Pacific fauna, while as a whole presenting very 
marked features in common, yet also present striking differences, ‘The 
vast extent of territory over which some of the marine types extend, 
through all the tropical part of the Pacific, may readily be explained 
from the course of the great western Equatorial Current and the east- 
ern counter currrent, which cannot fail to act as general distributers in 
space for the extension of a vast number of marine Vertebrates and 
Invertebrates. A similar extensive geographical range from north to 
south has also been observed in the distribution of some of the Mol- 
lusks, Echini, and Starfishes, which extend all the way from the south- 
ern extremity of South America to the Panamic region. The course of 
the northerly current setting along the west coast of South America 
must of course act as a distributer of the marine fauna of that region. 
There are, indeed, a number of genera in the deep water, and to some 
extent also in the shallower depths, which show far greater affinity with 
the Pacific than with the Atlantic fauna. Of course, further explora- 
tions may show that some of these genera are simply genera of a wider 
geographical distribution ; but I think a sufficiently large proportion of 
the deep-sea fauna will still attest the former connection of the Pacific 
and the Atlantic. 
In the first part of our cruise I was somewhat disappointed in the rich- 
ness of the deep-sea fauna in the Panamie district. It certainly does not 
