80 SPOLIA ZEYLANICA. 



Distribution. — A very common form in the Indo-Pacific 

 tropical and sub-tropical littoral waters. 



Remarks. — This species is related to H. fusco-rubra and 

 H. curiosa. 



HoLOTHURiA MACULATA (Brandt). 

 (Plate XI., fig. 18.) 



Sporadipus (Acolpos) maculata, Brandt 1835 (8). 

 Holothuria arenicola, Semper 1868 (38) ; Theel 1886 (42) ; 



Sliiiter 1887 (39) ; Fisher 1907 (11). 

 Holothuria maculata, Ludwig 1881 (25), 1883 (27), 1887 



(28), 1888 (30), 1897 (32) ; Lampert-1885 (19), 1895 



(21) ; Bedford 1898 (2), 1899 (3) ; Sluiter 1901 (41) ; 



Clark 1902 (10) ; Koningsberger 1904 (18) ; Koehler 



& Vaney 1908 (17). 



There are numerous specimens of this species in the 

 collections under examination. 



External Characters. — The ground colour of the body is 

 yellowish-white or pinkish-white ; on the trivium there are a 

 few scattered small broAvn spots. On the bivium there are 

 two rows of dark brown patches, varying from six to fifteen 

 in each row in different specimens. Occasionally these 

 markings are absent altogether. There are twenty small 

 tentacles. The ambvilacral appendages are similar all over 

 the body,, and are apparently true pedicels, as they have well- 

 developed sucking discs. These appendages are irregularly 

 scattered, and appear to be equally abundant on the trivium 

 and bivium. The anus is pentagonal and is surrounded by 

 five groups of papillae. 



Internal Structmre. — The calcareous ring is well developed. 

 There is generally a single small Polian vesicle and small 

 stone canal present. In a specimen examined by Theel there 

 were two Polian vesicles and a bundle of three stone canals on 

 the right side of the dorsal mesentery. No Cuvierian organs 

 are present in any of the specimens examined by me, but 

 their presence has been recorded by previous writers. The 



