GEOGRAPHICAL DISTRIBUTION OF CRUSTACEA. 1583 



some hardier species that belong to the seas or have a wide range in 

 distribution. Sea-shore Crustacea are not in themselves migratory, 

 and are thus unlike many species offish. Even the swimming Por- 

 tunidae are not known voluntarily to change their latitudes with the 

 season. 



The following is a brief recapitulation of the more prominent facts 

 bearing on these points. 



1. The distribution of individuals of many species through twelve 

 thousand miles in the Torrid zone of the Oriental seas. 



2. The very sparing distribution of Oriental species in Occidental 

 seas. 



3. The almost total absence of Oriental species from the west coast 

 of America. 



4. The world-wide distribution within certain latitudes of the 

 species we have called cosmopolites. 



5. The occurrence of closely allied genera at the Hawaiian Islands 

 and in the Japan seas. 



6. The occurrence of the same subtorrid species at the Hawaiian 

 Islands and at Port Natal, South Africa, and not in the Torrid zone 

 intermediate, as Kraussia rugulosa and Galene natalensis. 



7. The occurrence of identical species in the Japan seas and at 

 Port Natal. 



8. The occurrence of the same species (Plagusia tomentosa) in 

 South Africa, New Zealand, and Valparaiso; and the occurrence of a 

 second species (Cancer Edwardsii (?) ) at New Zealand and Valpa- 

 raiso. 



9. The occurrence of closely allied species (as species of Ampho- 

 roidea and Ozius) in New South Wales and Chili. 



10. The occurrence of the same species in the Japan seas and the 

 Mediterranean, and of several identical genera. 



11. The occurrence of a large number of identical species in the 

 British seas and the Mediterranean ; and also in these seas and about 

 the Canary Islands. 



12. The occurrence of closely allied, if not identical, species (as of 

 Palsemon) in New Zealand and the British seas ; and also of certain 

 genera that are elsewhere peculiarly British, or common only to 

 Britain and America. 



13. An identity in certain species of Eastern and Western America. 



