214 
THE YOYAHE OF H.M.S. CHALLENGEE. 
Madagascar (Ludwig), Djedda, Eed Sea and Indian Ocean (Ludwig), Querimba, 
Eed Sea (Semper), Ualan (Bra,ndt), (?) Eadack Islands (Chamisso and Eysen- 
hardt). Sandwich Islands and Society Islands (Selenka), Philippine Islands, 
Navigator Islands, Fiji Islands, Nicobar Islands, Amboina, Batchian, Molucca 
Islands (Semper), Macassar, Timor, Padang, and Pulo Tibul (Ludwig), Havana, 
Jamaica, and Tahiti (Ludwig), Darros Island (Bell). 
(Mus. Holm.) Several specimens from Tonga, Fiji Islands, and Penope. As a rule 
the specimens are supported by tables, which have the small annular disk smooth, 
but I even found, not unfrequently in the very same specimen, disks with spines 
on the margin. 
Holothuria atra, var. amhoinensis. Holothuria atra, Selenka, 1867. Holoihuria 
amhoinensis, Semper, 1868. 
Habitat. — Am boina (Selenka), Puerto Cabello in Venezuela (Ludwig), Mozambique 
(Bell). 
This form is scarcely distinct from the preceding species, from which it differs mainly 
in the fact that the annular disk bears spines ; but even Holothuria atra has 
sometimes such spines. 
(Mus. Holm.) One specimen, 350 mm. long, from Tonga exactly resembles 
Holothuria coluber of Semper in external appearance. Colour almost black ; 
tentacles, pedicels, and papillae light yellowish-brown. Four slender Polian 
vesicles and a single madreporic canal with elongate bipartite tubercle. Calcareous 
ring of the usual shape and size. Disks of the tables slightly better developed 
than in Selenka’s Holothuria atra, and with larger spines on the margin ; the 
spire with eight to twelve teeth at the top. 
Holothuria puUa, Selenka, 1867; Ludwig, 1881. Cl) Holothuria (svihgenus Microthele) 
. CBthiops, Brandt, 1835. 
Habitat. — Amboina (Selenka), Ualan (Brandt), (?) Ugi Australia, and (?) Mozambique 
(Bell). 
Almost completely like Holothuria atra; differs from it by possessing Cuvierian 
tubes, a character of very subordinate importance considering the well-known 
fact that individuals of the very same species vary greatly in this respect. 
Holothuria grisea, Selenka, 1867. 
Habitat. — Hayti (Selenka), Surinam and Eio Janeiro (Semper), St. Thomd and Eolas 
(Greeff), Brazil (Ludwig). 
Differs from Holothuria atra principally in the fact that the fenestrated plates are 
collected in circles in the hitegument. 
(Mus. Holm.) One specimen from Brazil. Length, 135 mm. Tentacles, 
twenty-one, the ventral slightly smaller. Ventral pedicels more densely 
crowded than the dorsal papillae, which are placed on low warts. Colour in 
