HOLOTHURIOrDEA OF THE INDIAN OCEAN. 183 



brown. A . lecanora, on the other hand, is Hghter on the trivium 

 and has a light patch around the anus. The spicules of both 

 forms are exactly alike, but in A. lecanora they are stated by 

 most writers to be arranged in little groups. I have not had 

 access to a large series of these two species, so that I am not 

 in a position to give an opinion on the value of these two 

 distinguishing characters. Perhaps the most striking is the 

 light circular area around the anus, and this would appear 

 to be constant. In a Japanese specimen of A. lecanora I 

 have been unable to satisfy myself that there is any distinct 

 arrangement of the spicules into groups. Any investigator 

 . who has the opportunity of examining a large series of these 

 two forms would do well to go into the question of colour and 

 spicular differences. 



General Distribution . — Indo -Pacific . 



AcTiNOPYGA ECHiNiTEs (Jager). 

 (PI. XXIX., fig. 7.) 



Miilleria echinites, Jager 1833 (7) ; Selenka 1867 (22) ; 

 Semper 1868 (23) ; Ludwig 1882 (14), 1887 (15), 

 1899 (17) ; Lampert 1885 (10), 1895 (12) ; Theel 

 1886 (26) ; Whitelegge 1897 (28), 1903 (29) ; Sluiter 

 1901 (25) ; Pearson 1910 (20). 



Actinopyga echinites, Bedford 1898 (1). 



A fairly common form in the Indo-Pacific region. It is 

 well represented in most of the collections at my disposal. 



External Characters. — A large robust form frequently attain- 

 ing a size of over 250 mm., though generally less than this in 

 preserved specimens. The body is much stouter in the 

 middle than in most Holothurians, and the greatest width may 

 be nearly half the total length. The body is sUghtly curved 

 and becomes narrower at each end. The mouth is ventral and 

 is surrounded by a distinct rim formed of papillae. The anus 

 is sHghtly dorsal and is sm-rounded by five teeth, which often 

 have an iiTegular surface. There are twenty dark brown 



