HOLOTHTJRIOIDEA OF THE INDIAN OCEAN. 49 



NOTES ON THE HOLOTHURIOIDEA OF THE 

 INDIAN OCEAN. 



By Joseph Pearson. 

 (With ten Plates.) 



1.— THE GENUS HOLOTHURIA. 



THE following notes on the littoral Holothurioidea of the 

 Indian Ocean have been brought together during the 

 preparation of a monograph on the subject. Zoogeographically 

 the Indian Ocean cannot be separated from the tropical 

 portion of the Pacific, since with few exceptions the species of 

 littoral Holothurians of this region have a wide distribution 

 extending from the east coast of Africa to the eastern portion 

 of the Pacific. The majority of the Holothurians of Ceylon, 

 for instance, occur throughout the tropical waters of the 

 Indo-Pacific region, and are found on the east coast of Africa 

 from Suez to the Cape of Good Hope, the coast of Asia from 

 the northern end of the Red Sea to the islands of Japan, 

 the East Indies, the north coast of Australia, the Pacific 

 Islands, and in some cases the western coast of South America. 

 On the grounds of not having sufficient material from the 

 Pacific Ocean, and also in order to confine the work within 

 reasonable Hmits, it has been decided to include only those 

 Holothurians found in the waters which lie between latitudes 

 30° N. and 30° S. and longitudes 30° E. and 130° E. 



The proposed monograph will be based i;pon collections 

 examined and described by the present writer during the past 

 few years. I refer to the collections made by Professor 

 Herdman, F.R.S., in Ceylon, by Messrs. Simpson and 

 Rudmose Brown in the Mergui Archipelago, by Mi'. Simpson in 

 Portuguese East Africa, and to the collection of Holothurians 

 in the Colombo Museum. To these have been added the 

 Holothurians sent by Professor Stanley Gardiner, F.R.S., 

 H ~ 6(5)13 



