12 PROCEEDINGS OF THE CALIFORNIA 
The following papers by Dr. J. G. Cooper were submitted: 
The Origin of Californian Land-Shells. 
BY J. G. COOPER, M. D. 
In previous articles I have given some observations on the Distribution and 
Variations of the Californian Banded Land-shells, which naturally lead to the 
consideration of their probable origin or past history. 
In the ‘‘ Bulletin of the Museum of Comparative Zodlogy,’’ (Cambridge, 
Mass., June, 1873, p. 202), Mr. W. G. Binney writes, ‘‘ the west alone is left 
to us from whence to trace the Pulmonate Fauna of the Pacific region, and 
there the secret of its origin lies buried under the Pacific Ocean.” 
Mr. Binney probably alluded to the supposed existence of a continent 
jn the South Pacific, embracing the mountain summits now forming the 
archipelago of Oceania, which became submerged, as Prof. Dana suggests, 
during the later tertiary period, while most of California was emerging from 
the ocean. 
But even if this were proved to have happened, the great distance of the 
nearest islands (the Hawaiian) from us, and the great depth of the ocean 
between, as well as north of them, besides the total dissimilarity of their 
living land-shells from ours, forbids any supposition of a former land connec- 
tion by which such animals could travel directly from one country to the other. 
A glance at a globe shows that the islands, besides being tropical and wholly 
south of lat. 23°, are as far from us as the Aleutian Islands, the Arctic Ocean, 
or Florida, and I propose to show that whatever migration to California has 
occurred, came from the direction of the regions named last. 
No confirmation is given to a derivation from the west, by the more probable 
former existence of an ‘‘Atlantis’’ connecting the two continents across the 
Atlantic, the few island remnants of which really contain several species of 
land-shells common to one or both sides. 
The great similarity of our banded groups to those of Europe has always 
been an argument for supposing them to have had a common origin. The 
same similarity is found in many others of our animals as well as plants, and 
is plainly connected with the well-known similarity of climates in the two 
countries. But as the known laws of nature do not permit us to consider 
climate as the cause of specific resemblances, we must look for some other 
way of accounting for them in this case. 
The fact that very similar species exist in Japan and the Amoor Valley, 
Siberia, contradicts, indeed, the theory of climatic causes, since we know that 
the climate of those regions is very similar to that of our Atlantic States, 
where no similar species exist. At the same time, their existence there sug™ 
gests the probable central point from which all originated. 
Going back in geological history to the supposed beginning of all living 
species, few, if any, of the terrestrial, can be traced farther back than the 
