XVII 
DISTRIBUTION OF THE SHELLS 
417 
from islands in the central parts of the Pacific occurring here, 
deserves notice, for not one single sea-shell is known to be 
common to the islands of that ocean and to the west coast of 
America. The space of open sea running north and south off 
the west coast separates two quite distinct conchological 
provinces ; but at the Galapagos Archipelago we have a halting- 
place, where many new forms have been created, and whither 
these two great conchological provinces have each sent several 
colonists. The American province has also sent here representa¬ 
tive species ; for there is a Galapageian species of Monoceros, 
a genus only found on the west coast of America ; and there 
are Galapageian species of Fissurella and Cancellaria, genera 
common on the west coast, but not found (as I am informed by 
Mr. Cuming) in the central islands of the Pacific. On the 
other hand, there are Galapageian species of Oniscia and Stylifer, 
genera common to the West Indies and to the Chinese and 
Indian seas, but not found either on the west coast of America 
or in the central Pacific. I may here add, that after the com¬ 
parison by Messrs. Cuming and Hinds of about 2000 shells 
from the eastern and western coasts of America, only one single 
shell was found in common, namely the Purpura patula, which 
inhabits the West Indies, the coast of Panama, and the Galapagos. 
We have, therefore, in this quarter of the world, three great 
conchological sea-provinces, quite distinct, though surprisingly 
near each other, being separated by long north and south spaces 
either of land or of open sea. 
I took great pains in collecting the insects, but, excepting 
Tierra del Fuego, I never saw in this respect so poor a country. 
Even in the upper and damp region I procured very few, 
excepting some minute Diptera and Hymenoptera, mostly of 
common mundane forms. As before remarked, the insects, for 
a tropical region, are of very small size and dull colours. Of 
beetles I collected twenty-five species (excluding a Dermestes 
and Corynetes imported wherever a ship touches) ; of these, two 
belong to the Harpalidae, two to the Hydrophilidae, nine to three 
families of the Heteromera, and the remaining twelve to as many 
different families. This circumstance of insects (and I may add 
plants), where few in number, belonging to many different families, 
is, I believe, very general. Mr. Waterhouse, who has published 1 
1 Ann. and Mag. of Nat. Hist. vol. xvi. p. 19. 
2 E 
