HOLOTHURTOIDEA OF THE INDIAN OCEAN. 177 



long in the contracted condition, and i« light yellow in colour. 

 The pedicels on the triviuni are crowded together and form a 

 kind of sole, as described by Theel. The dorsal papillee are 

 not so numerous or so large. There are slight elevations at 

 each side of the body, which may be due to the contraction 

 of the specimen, or they may be similar projections to those 

 described in Argiodia maculata. There are twenty tentacles. 



Internal Structure. — The calcareous ring is similar to that 

 of Argiodia maculata. There is one large Polian vesicle, but 

 no stone canal can be seen. Theel records the presence of a 

 single stone canal. There are no Cuvierian organs present, 

 although they were present m Theel's type specimen. 



Spicules. — These consist of tables and knobbed buttons. 

 The tables are 55 ^ in diameter and about the same height. The 

 buttons, which are about 80 [i. long, have four or five pairs of 

 holes, and in the centre bear three or four knobs. 



General Distribution. — Madeha, Red Sea. A rare form, with 

 a curious distribution. 



Remarks.— Only m one respect does this species differ from 

 A. maculata, and that is in the nature of the buttons. Apart 

 from this character the two species appear to be identical. 

 I cannot admit with Theel and Bedford the possibility of this 

 species being identical with A. parvula, as the buttons are 

 different, and the calcareous rings of the two species are 

 dissimilar. 



Argiodia parvula (Selenka). 



(PI. XXVIII., ag. 4.) 



Mulleria parvula, Selenka 1867 (22) ; Lampert 1885 (10) ; 

 Theel 1886 (26). 



Actinopyga parvula, Bedford 1898 (1) ; Fisher 1907 (5). 



There are several specimens from Prof. Gardiner's Maldive 

 collection and one specimen from the Dubhn Museum obtained 

 from the Seychelles. 



External Characters. — This appears to be a very small 

 species, and I cannot find any record of a specimen over 50 mm. 

 in length. The largest specimen I have examined is only 



