1554 CRUSTACEA. 



Menippe Rurophii ; East Indies ; Rio Janeiro and the West Indies. 



Chlorodius exaratus ; Pacific Islands ; East Indies ; West Indies. 



Lysiosquilla scabricaudis j Indian Ocean ; West Indies ; Brazil ; South Carolina. 



From the survey already made, it is apparent, that the three grand 

 divisions of the seas and coasts adopted in the preceding table, have 

 very few species in common, and they correspond to a natural geo- 

 graphical arrangement. They constitute three kingdoms, to which 

 two should be added, one for the Arctic Seas, and the other for the 

 Antarctic. These kingdoms are : — 



I. The Occidental Kingdom, embracing the Atlantic and Pacific 

 coasts of America to the frigid region, or some point in the subfrigid 

 region. 



II. The European Kingdom, extending from Cape Horn (or Cape 

 Agulhas) to the Shetlands inclusive, and embracing the adjoining 

 islands. 



III. The Oriental Kingdom, including the east coast of Africa, the 

 south and east of Asia, and the islands of the Indian and Pacific 

 Ocean, exclusive of the American continent. 



IV. The Arctic Kingdom, including Norway, Iceland, Greenland, 

 the Alascha Archipelago, and adjoining parts of the coasts of America 

 and Kamtschatka, with other Arctic lands. 



V. The Ant-arctic Kingdom, embracing Fuegia, the Falklands, 

 Southern New Zealand, and the lands or islands of the Antarctic Seas. 



Each of the first three kingdoms are naturally divided into three 

 subkingdoms : a north, a middle, and a south, corresponding severally 

 to the North Temperate, Torrid, and South Temperate zones of sea- 

 temperature. The importance of these divisions will be a subject of 

 further remark beyond. 



The summary of the results in the preceding table, presents some 

 striking facts. 



We observe, first, that there is a ratio of 1 : 1*5 between the 

 Maioids of the A and C divisions (that is between those of the Occi- 

 dental and Oriental seas, as just explained), while the ratio is about 

 1 : 4£ for the Cancroids. So also, while the ratio of the A and B 

 divisions together (Occidental and European) to C (Oriental) is for 

 the Maioids, nearly 1 : 1, it is for the Cancroids, 1 : 3. Here is a 

 wide difference between the Occidental and Oriental seas as regards 

 these groups. This last ratio is for the Corystoids nearly that for the 

 Maioids, or more exactly, 1 : 075 ; and for the Grapsoids it is 1:2; 



