1887.] FROM THE ANDAMAN ISLANDS. 145 



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

 to be at once clistin2;viished by the absence of the remarkably modi- 

 fied turciform spicules. On the whole, it stands nearest to H. scahra, 

 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 specimens 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 associated as H. mar- 

 morata ; the complete absence of a circular disposition of the 

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

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

 their affinity with H. martnorata. 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 and 

 widely distributed species which grows to a great size. 



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



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

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

 which are larger and nioie closely j^acked anteriorly than posteriorly ; 

 five or more small papilke around the anus. 



Suckers on central surface 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 PoHan vesicle. Genital tubes short and 

 numerous. Apparently no Cuvierian organs. The only calcareous 

 deposits are in 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. 



Eigs. 1-3. Moira stygia, X li. 



Fig. 1. With spines, and from the side. 



2. Test deiuided, to show tlie arrangement of the plates. 



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



4. Spicules of Haplodactyla andamanensis. 



5. Spicule of Psciidocucumis acicula. 



6. Spicules of Holothuria albida. 



7. Spicules oi Holothuria cadclli. 



8. Spicules oi Holoihtiria papillata. 

 Figs. 4-8 X 500. 



Proc. Zool. Soc— 1887, No. X. 10 



