HOLOTHURIOIDEA OF THE IJSfDIAN OCEAN. 71 



on the other hand, the pink colour was confined to a narrow 

 strip on the middle of the trivium. The sides were graj^ and 

 the middle of the bivium was black. Nevertheless there was 

 no difficulty in distinguishing these dark-coloured specimens 

 from Holothuria atra. On no occasion have I found any 

 variation in the nature of the tables in the skin. I consider 

 this species a good one, showing small but constant 

 variations from H. atra. 



Holothuria monacaria (Lesson). 



(Plate X., fig. 13.) 



Psolus monacaria, Lesson 1830 (22) ; Jager 1833 (14). 

 Holothuria flammea, Quoy & Gaimard 1833 (36). 

 Holothuria fusco-punctata, Quoy & Gaimard 1833 (36). 

 Holothuria fasciola, Quoy & Gaimard 1833 (36). 

 Stichopus flammeus, Brandt 1835 (8). 

 Stichopus gyrifer, Selenka 1867 (37). 

 Labidodemas leucospilus, Haacke 1880 (12). 

 Holothuria monacaria, Lampert 1885 (19), 1889 (20), 1896 



(21) ; Theel 1886 (42) ; Sluiter 1887 (39), 1901 (41) ; 



Ludwig 1887 (29), 1888 (30), 1899 (32) ; Koehler 1895 



(15), (16) ; Bedford 1898 (2), 1899 (3) ; Pearson 1903 



(33), 1910 (34) ; Fisher 1907 (11). 



This species is well represented in the various collections 

 under examination. 



External Characters. — A well-marked form. There are 

 papiUae on the bivium and pedicels on the trivium. The 

 ground colour on the back is auburn, that on the trivium 

 brown. The pedicels and papillae are canary -yellow, and each 

 one is surrounded by a light circular patch. Sometimes these 

 light areas join up longitudinally so as to give a longitudinally 

 striped appearance. The pedicels are slightly more crowded 

 than the papillae. Generally the pedicels are arranged in 

 three double rows, but in some living specimens I have 

 examined there was no such arrangement. The papillae are 

 arranged in about six more or less regular rows rumiing along 



