HOLOTHURIOIDEA OF THE INDIAN OCEAN. 51 



Holothuria scabra, Jager. 

 Holothuria spinifera, Theel. 

 Holothuria ocellata, Jager. 

 Holothuria martensii, Semper. 

 Holothuria albiventer, Semper. 



Genus HOLOTHURIA. Linn. 1758. 



Bohadschia, Jager 1833. 

 Trepang, Jager 1833 {partim). 

 Sporadipus, Brandt 1835. 

 Cystipus, Haacke 1880. 



Usually 20 peltate tentacles, exceptionally more or less. 

 Ambulacral appendages pedicels alone, papillae alone or with 

 both (pedicels on the trivium and papillae on the bivium). 

 Ambulacral appendages generally scattered, very rarely dis- 

 posed in rows. As a rule the trivium is not clearly separated 

 from the bivium. Thie anus is devoid of calcareous teeth. 

 There is a single bundle of genital tubes on the left side of the 

 dorsal mesentery. Tentacular ampullae present. The cal- 

 careous ring without posterior prolongations and without long 

 retractor muscles, stone canals often numerous ; respiratory 

 trees well developed, the left branch being intimately connected 

 with a rete mirabile. Cuvierian organs often present. 



Holothuria hamata, n. sp. 



(Plate v.; Plate VI., fig. 2.) 



Two examples from Suez Bay, 5-9 fathoms, dredged by 

 Mr. Cyril Crossland. 



One of the specimens was narcotized in alcoholic sea water 

 before preservation, and has retained more or less the propor- 

 tions of the living animal. It is 225 mm. long and 54 mm. 

 broad. The other specimen was put immediately with strong 

 spirit and is greatly contracted. 



External Characters. — After several years' immersion in 

 strong spirit the animals have lost all colour, and are of a 

 uniform yellowish-brown, slightly darker on the bivium than 

 on the trivium. I have the advantage of some manuscript 



