1887.] FROM THK ANDAMAN ISLANDS. 145 



there are more than tlnee pairs of lioles ; from that species it is 

 to be at once distingnislieJ by the absence of the remarkably modi- 

 fied turciform spicules. On the whole, it stands nearest to //. scabra, 

 but is distinguished by its speckled and less dense integument, and 

 the absence of the median ventral groove. A specimen ICO millim. 

 long has the greatest circumference 40; one 140 milhm. is only 10 

 millim. round at the anus. 



Three smaller specinsens differ from the more matured, two by a 

 larger amount of orange in their coloration, and the third by the 

 greater stiffness of the skin. 



HOLOTHURIA MARMORATA. 



I have had great difficulty in coming to a definite conclusion as 

 to the name to be given to the specimens now assoriated as H. inar- 

 morata ; the complete absence of a circular disposition of the 

 pigmentation prevents their association with H. aryus ; on the other 

 hand, the comparatively small size of the oesophageal ring is against 

 their affinity with H. marniorata. I believe the fact of the matter 

 is that Dr. Theel is justified in his supposition that these two species 

 and some others are but varieties or various stages of a variable aud 

 widely distributed species which grows to a great size. 



HoLOTHURIA PAPILLATA. (Plate XVI. fig. 8.) 



Twenty tentacles. Body elongated, may be wider iu its hinder 

 than in its two anterior thirds ; prominent scattered dorsal papillge, 

 which are larger and more closely jiacked anteriorly than posteriorly ; 

 five or more small pajjillio around the anus. 



Sucliers on central suiface only, arranged in two irregular rows, 

 which unite posteriorly ; each sucker is placed on a yellowish papil- 

 liform process. Colour dark slate-grey above, lighter below. 



Body-wall thin, the parts of the oesophageal ring are small, the 

 ampullae long ; one large Polian vesicle. Genital tubes short and 

 numerous. Apparently no Cuvierian organs. The only calcareous 

 deposits are iu the form of stools (Plate XVI. fig. 8). 



Notwithstanding these numerous negative characters, the large 

 size and well-developed papillae must make this a very conspicuous 

 species. 



It may be 280, 320 long, and 60, 80 millim. broad. 



EXPLANATION OF PLATE XVI. 



Figs. 1-3. Moimstygia, X U. 



Fig. L A^'ith spines, and from the side. 



2. Test denuded, to show flie arrangement of the plates. 



3. Test from above, to sliovv the disposition of the ambulacra . 



4. Spicules of Haplodactijla avdamanensis. 

 6. Spicule of PgcudocM-utnis ackula. 



6. Spicules of Holothuria albida. 



7. Spicules oi Holothuria cadelli. 



8. Spicules oi Holothuria papillata. 

 Figs. 4-8 X 500. 



Proc. Zool. Soc— 1887, No. X. 10 



