HOLOTHURIOIDBA OF THE INDIAN OCEAN. 77 



HOLOTHURIA FUSCO-RUBRA, Theel. 

 (Plate XI., fig. 16.) 



Holothuria fusco-rubra, Theel 1886 (42); Sluiter 1901 (41); 

 Fisher 1907 (11). 



A few specimens are found in the collections under exami- 

 nation. 



External Characters. — Body is robust, and is covered with 

 numerous well-formed pedicels on the trivium and less 

 numerous papillae on the bivium. There are five groups of 

 papiUse around the anus. There are twenty tentacles. The 

 body is purphsh-brown in alcohol. This colour is seen in the 

 sections of the integument which it is customary to prepare 

 for the microscopical examination of the spicules. 



Internal Structure. — In the specimen examined by me the 

 calcareous ring is slightly different from that figured by Theel. 

 There are two PoUan vesicles and a single stone canal. The 

 left respiratory tree is more bulky than the right, but does 

 not extend so far forward. Theel and Fisher stated that the 

 species possesses Cuvierian organs, but they are not present 

 in the specimen under examination. 



Spicules. — These consist of tables and buttons. The disc 

 tables vary in size according to the state of their development. 

 The largest tables are 55 ^J. in diameter, and have four central 

 holes and a ring of smaller peripheral holes. The edge of the 

 disc is spiny. The tables are reduced or absent. Frequently 

 the disc is reduced and possesses no peripheral holes, and then 

 has the appearance of the reduced disc of H. j^ardalis. The 

 buttons are irregular. In their most regular form they have 

 three pairs of holes and are about 65 [>• long. Frequently some 

 of the holes are missing, and these asymmetrical forms are 

 the commonest. The pedicels are supported by long irregular 

 buttons having several pairs of holes. The papillae are sup- 

 ported by irregular branched rods. 



Distribution. — Indo-Pacific. Xot very common. 



