IV. DISTRIBUTION. 



The limits here assigned to the Pacific Region extend from the South Pole 

 along the meridian of Cape Horn to Cape Horn and along the west coast of the 

 American continent to Cape Prince of Wales. From here across Bering Strait 

 to Cape Deshnef and along the east coast of the Eurasian continent to Cape 

 Buhis by Singapore. Thence across the Strait of Malacca to the north coast 

 of Sumatra, along the eastern coast of Sumatra across the Sunda Strait to the 

 north coast of Java and the group of islands east of it, and across the other 

 straits separating these islands, to the northeast coast of Timor. From here 

 across the Arafura Sea to Bathurst Island and along its north coast across 

 Dundas Strait to the Coburg Peninsula of northern Australia. Thence along 

 the north and east coasts of Australia, across Bass Strait, and along the east 

 coast of Tasmania to the South Cape and farther, along the meridian of this 

 Cape, to the South Pole. 



If the Geodidae of the Pacific are compared with those of other regions it is 

 seen that, although several of the Pacific species are similar to species found out- 

 side the Pacific, not a single one of the former is really identical with any of the 

 latter. 



With the genera, however, it is different. Of the seven genera five are 

 represented both in the Pacific and ultra-Pacific regions, only two, Pachy- 

 matisma and Geodinella, being confined to one or the other, Pachymatisma to 

 the ultra-Pacific and Geodinella to the Pacific region. Of the five genera 

 common to both regions two, Caminella and Sidonops, are about equally dis- 

 tributed in the two regions; two, Caminus and Isops, are represented by a 

 larger number of species in the ultra-Pacific region than in the Pacific ; and one, 

 Geodia, is richer in Pacific than in ultra-Pacific species. 



The total numbers of the species of the seven genera and the absolute and 

 percentage numbers of their Pacific species are tabulated below. 



254 



