72 



MATiTJAL OF THE MOLLTJSCA. 



of Africa to Easter Island in the Pacific, embracing three-fifths 

 of the circumference of the globe and 45° of latitude. This 

 great region might, indeed, be subdivided into a number .of 

 smaller provinces, each having a particular association of species 

 and some peculiar shells, such as the Eed Sea, the Persian Gulf, 

 Madagascar, &c. ; but a considerable number of species are 

 found throughout the province, and their general character is 

 the same.* Mr. Cuming obtained more than 100 species of 

 shells from the eastern coast of Africa, identical vsdth those 

 collected by himself at the Philippines, and in the eastern coral 

 islands of the Pacific, f This is pre-eminently the region of 

 coral reefs, and of such shell-fish as affect their shelter. The 

 number of species inhabiting it must amount to several thou- 

 sands. The Philippine Islands have afforded the greatest 

 variety, but their apparent superiority is due, in a measure, to 

 the researches of Mr. Cuming ; no other portion of the province 

 has been so thoroughly explored 4 



Amongst the genera most characteristic of the Indo-Pacific, 

 those marked (*) are wholly wanting on the coasts of the At- 

 lantic, but half of them occur fossil in the older tertiaries of 

 Europe. Those in italics are also found on the west coast of 

 America. 



The strictly littoral species vary on each great line of coast : 

 for example, Littorina intermedia and Tedaria pagodus occur on 



* See Mrs. Somerville's Physical Geography, ii. p. 233. 



t Journal Geol. Soc. 1846, vol. ii. p. 268. 



X Mr. Cuming collected 2,500 species of sea-shells at the Philippines, and estimatea 

 the total number at 1,000 more. The genera most developed are Conus, 120 sp. ; 

 Pleurotoma, Ida ; Mitra, 250; Odumbella, 40; Cypraa, 50 ; Natica, 50; Chiton, 30; 

 Tellina, 50. 



