DISTRIBUTIOX OF THE SHELLS 41? 



from islands in the central parts of the Pacific occurring here, 

 deserves notice, for not one single sea -shell is knowTi to be 

 common to the islands of that ocean and to the west coast of 

 America. The space of open s^a running north and south ofi' 

 the west coast separates two quite distinct conchological 

 provinces ; but at the Galapagos Archif)elago we have a halting- 

 place, where man\- new forms have been created, and whither 

 these two great conchological provinces ha\e each sent several 

 colonists. The American province has also sent here representa- 

 tive species ; for there is a Galapageian sf)ecies of Monoceros. 

 a genus onlj- 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 tlie Pacific On the 

 other hand, there are Galapageian species of Oniscia and Stj'lifer, 

 genera common to tlie 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 eind western coasts oi America, onh" one single 

 shell was found in common, nameK- 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 

 Tlerra del Fuego. I never saw in this respect so jKKDr a countrj-. 

 Even in the upper and damp region I procured verj- few, 

 excepting some minute Diptera and Hj-menoptera, mostly of 

 common mundane forms. As before remarked, the insects, for 

 a tropical region, are of ver\- small size and dull colours. Of 

 beetles I collected t\vent}"-five species (excluding a Dermestes 

 and CorjTietes imported wherever a ship touches ; 01" these, two 

 belong to the Harpalidse, 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 ma\- add 

 plants" , where few in number, belonging to man\- different families, 

 is, I believe, verj- general. Mr. Waterhouse, who has published ' 



' Aon, aus -J/jj*. tf \j:. Hij:. rol. xvi. p. 19. 

 2 1£ 



