REPORT ON THE HOLOTHHRIOIDEA. 
219 
in its top. Buttons of tho usual shape with six holes. The dorsal pedicels 
alone have supporting rods which are spinous and tapered towards the ends. 
Habitat . — Sandwich Islands and Society Islands (Selenka), Philippine Islands, 
IMacKean’s Islands, Sunda Islands, Mozambique and Aden (Semper), Zanzil:)ar 
(Selenka), Java (Selenka, Ludwig), Navigator Islands (Semper, Ludwig), Nicobar 
Islands and Hong Kong (Ludwig), Darros Island (Bell), Ualan (Brandt), Bowen 
(Ludwig). 
(]\Ius. Holm.) Two specimens from Navigator Islands, one from Port Dennor and one 
from Peru. Moreover, the Godeffroy Museum has specimens from the following 
localities : Tahiti, Massua, Eooa, Fiji Islands, Rockhampton, and New Britain. 
In all these specimens the ambulacral appendages appear to be of nearly equal 
size on the dorsal and ventral surfaces ; but, at the same time, I always found 
the ventral ones cyhndrical, and the dorsal, on the contrary, more papilliform. 
The ventral have a well-developed terminal plate and bilaterally symmetrical, 
perforated supporting plates ; the dorsal have a rudimentary terminal plate and 
numerous simple spinous or slightly branched or even perforated rods. Besides, 
the ventral appendages are always more numerous than the dorsal. Thus 
the forms examined by me apparently present examples of dorsal appendages 
forming a transition between pedicels and true papillae, and show that it is rather 
difficiilt to draw a line of demarcation between them. That the forms I have 
seen really belong to this species is proved by the whole internal and external 
organisation. The colour varies from dark brown to light reddish-brown. A 
single Polian vesicle and madreporic canal are present. The genital tubes are 
slender, and slightly dichotomously branched. The strongly-developed Cuvierian 
tubes are of a violet or reddish-colour. The disks of the tables are sometimes 
not very well developed, sometimes round or angular, with a large central hole, 
and several peripheral ones, and their margin is often uneven. 
Ilolothuria laguna, Haacke, 1880; Ludwig, 1883. 
Habitat . — Mauritius (Haacke, Ludwig), Mozambique (Bell). 
(Mus. Holm.) One specimen from Mauritius presented by Professor Mdbius. From 
the description of Ludwig as well as from my own researches, I cannot find any 
other character distinguisliing this form from the true Holotlmria vagabunda, 
than the fact that it has “ papillte ” instead of pedicels on the back ; but even in 
the later species the dorsal appendages present a great resemblance to “ papillae,” 
and I am therefore much inclined to annul this species. A re-examination 
and comparison of both forms will therefore be necessary. 
Holothuria difficilis, Semper, 1868. Mulleria parvula, Haacke, 1880 (according to 
Ludwig, 1883). 
The dorsal papillae very thinly scattered. Ventral surface with pedicels. The disks 
of the tables well developed, with numerous peripheral holes, and the spire 
