HOLOTHUEIOIDEA OF THE INDIAN OCEAN. 175 



has a uniform brown colour. Some specimens from Durban 

 Museum have a similar colour. 



The illustrations and descriptions of this species found in 

 the literature of the subject do not emphasize sufficiently the 

 appearance of the animal. This is undoubtedly due to the 

 fact that most, if not all, previous descriptions have been 

 made from preserved material. Undoubtedly the most 

 characteristic feature of this species is the series of prominent 

 lateral protuberances and the small dorsal wart-like out- 

 growths, and in all the preserved material at my disposal I 

 have been able to make these out only with the greatest 

 difficulty. In some specimens they appear to be entirely 

 absent. Whether there is any considerable amount of 

 variation in this respect I cannot say. In the only living 

 specimen I have been able to examine the lateral prominences 

 are well developed, as shown in PL XXVI. After this 

 particular specimen was preserved- the elevations were only 

 imperfectly seen, and the small dorsal tubercles disappeared 

 altogether * 



A livmg specimen taken on the Ceylon pearl banks measured 

 350 mm. long and 150 mm. in greatest breadth. There were 

 five large protuberances on each side of the body at the junction 

 of the bivium and trivium. These elevations stood out about 

 16 mm. beyond the general contour of the body. On each 

 radius of the bivium was a row of smaller tubercles, about a 

 dozen in each row. The ambulacral appendages consisted 

 of small papillae irregularly scattered on the bivium and 

 larger and more numerous pedicels on the trivium. In some 

 specimens, obviously due to contraction, there is a clear 

 distmction between the trivium and the rest of the body, as 

 the ventral surface forms a distinct sole. The colour during 

 life was uniform auburn-brown on the bivmm and a slightly 

 lighter colour below. 



* Since writing the above I have obtained another specimen of this 

 species from the Ceylon pearl banks. It had the typical yellow and 

 black blotches referred to above, and the lateral projections were not 

 well marked. It is probable, therefore, that the well-defined projections 

 shown in PI. XXVII. are not typical of the species. The figure is retained 

 as it was drawn from life, and it may be regarded as an unusual example 

 of the species, both as regards colour and the size of the lateral 

 projections. 



