618 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.5 



species possessing analogues which may have reached the islands directly 

 from the Caribbean via the Panama Portal, recent seasonal transportation 

 of larval stages by the Nino Current is indicated. 



(4) The 11 Galapagos species common to the Gulf of California- 

 Lower California region alone are evidence of the infiltration of a north 

 temperate fauna, with the transportation of larval stages by the California 

 Current and the Equatorial Countercurrent indicated. 



(5) The 5 Galapagos species common to the coast of Chile or Peru 

 alone are evidence of a lesser infiltration of the Subantarctic fauna, with 

 the Peruvian Coastal Current indicated as the means of transportation of 

 such species as have arrived. 



(6) The 5 Indo-Pacific species and 2 species with close Indo-Pacific 

 ties found in the Galapagos Islands indicate the transportation of larval 

 forms from trans-Pacific islands by the Equatorial Countercurrent. 



(7) The relation of the Galapagos fauna to the Indo-Pacific is better 

 indicated by genera, of which there are 10 common to both regions and to 

 none other, than by species, of which there are but 5. 



(8) Not only have species and genera originating elsewhere made 

 large contributions to the Galapagos fauna, but species, and even genera, 

 originating in the Galapagos Islands have made a smaller, but none the less 

 significant, contribution to the brachyuran faunas of the mainland and of 

 adjacent islands. 



(9) The absence from the Galapagos of the families Goneplacidae and 

 Gecarcinidae, and of the Sesarminae section of Grapsidae, is in keeping 

 with the volcanic theory of origin of the archipelago as proposed by 

 Darwin (1845), rather than with the subsidence theory proposed by 

 Baur (1891). 



