228 LITTORAL DISTRICTS. 



Cidaris metularia, Parasalenia gratiosa, 



Phyllacantbus dubia, Echinostrephua molare, 



Phyllacantbus veriicillata, Hipponoe variegaia, 



Diadema setosum, Toxopneustes pileolus, 



Echinothrix turcarum, Clypeaster scutilbrmis, 



Echinothrix calamaris, Laganum depressum, 



Echinothrix Desorii, Echinoniius cyclostomus, 



Hetorocentrotus maniniillatus, Maretia planulata, 



Colobocentrotus atratus, Brissus carinatus, 



Echinometra lucunter, Metalia sternalis, 



Echinoraetra oblonga, Metalia maculosa. 



There is a set of species which range as far in longitude, but do not ex- 

 tend as far north in latitude, having thus far not yet been found extending 

 to any considerable degree north of the equator, and being absent in the 

 Sandwich Islands and the Bonin Islands, though they arc found as far cast 

 as the Low Islands in the South Pacific, ami have also the same general 

 southern limits as the preceding species. They are : — 



Phyllacantbus baculosa, Fibularia volva, 



Phyllacantbus imperialis, Clypeaster hutnilis, 



Stomopneustes variolarie, Peronclla rostraia, 



Ilcterocentrotus trignnarius, Nucleolites recens. 

 Salmacis DoBSumieri, 



Indo-African District | PI A). 



The species which are eminently characteristic of the East Coast of Africa 

 and of the Indo-African District (PI. A) are few; they extend as far as the 

 West Coast of Australia, to the East Indian Archipelago, and even to the 

 southern part of Japan. These are Echinodiscus auritus. E. laevis and 

 biforis, Echinolampas oviformis, Salmacis sulcata and bicolor. With the 

 exception of Schizaster gibberulus, Moira stygia, and Mellita erythrea, 

 the Red Sea is inhabited by the species of the Indian Ocean and of the 

 Indo-Pacific Belt. 



Metalia maculosa, Toxopneustes pileolus. and Echinanthus testudinarius ex- 

 tend as far as the West Coast of Central America. 



East Indian District (PI B). 



The species belonging strictly to this district, some of which extend as far 

 south and east as the Feejee Islands and New Caledonia, westward to the 

 Persian Gulf, and northward to the southern coast of Japan, are : — 



