56 SPOLIA ZEYLANICA 



up as many as fifty specimens after five minutes' dredging 

 from a small boat. On the western side of the Island it is 

 apparently very rare, as I have not found a single specimen 

 during a two-months' trawling and dredging expedition in 

 the shallow-water region to the north of Colombo. Professor 

 Herdman obtained only a single specimen during his visit in 

 1902. 



HoLOTHURiA ARGUS (Jager). 

 (Plate VII., fig. 5.) 



Bohadschia argus, Jager 1833 (14) ; Bell 1889 (7). 



Holothuria argus, Semper 1868 (38) ; Ludwig 1882 (26) ; 

 Lampert 1885 (19), 1889 (20) ; Theel 1886 (42) ; 

 Bell 1887 (6) ; Koehler 1895 (15) ; Sluiter 1901 (41). 



One specimen from Ternate (Frankfurt Museum), 140 X 

 65 mm. 



One specimen from Amboina (Geneva Museum), 295 X 

 70 mm. 



External Characters. — Colour, yellowish-brown below and 

 slightly darker above. The upper surface is characterized by 

 the presence of numerous well-defined circles varying in 

 diameter from 1 to 12 mm. In some cases several of these 

 areas are joined up together, thus forming an irregular patch. 

 The centre of each circle is occiipied by a pedicel, the base of 

 which is coloured dark brown ; towards the circumference the 

 integument gradually changes from yellow to dark brown ; 

 outside the circumference there is a light yellow area which 

 gradually merges into the brown colour of the general 

 integument. In addition to the pedicel in the centre of the 

 circle, there are other ambulacral appendages irregularly 

 arranged within the circle as well as on the general surface of 

 the bod3^ 



The ambulacral appendages consist of pedicels. Those on 

 the trivium have much better developed terminal discs. The 

 pedicels are irregularly scattered and are extremely numerous, 

 especially on the trivium. Some of the ambulacral appendages 

 on the bivium are devoid of sucking discs and terminal 

 plates. 



