REPORT ON THE HOLOTHURIOIDEA. 
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Thy one gibber {Stolus), Selenka, 1867; Semper, 1868. 
Deposits like those in Thyonc ga/mmdta , — oval button-like plates with about four 
holes ; and reticulate cups. The pieces of the calcareous ring are firruly united. 
Habitat . — Panama (Selenka). 
Thyone oheni, Bell, 1884. 
Excepting terminal plates in the pedicels, no deposits. Pedicels closely packed. 
Habitat . — Port Jackson (Bell). 
IV. Calcareous ring composed of five radial pieces alone. 
Thyone chilensis, Semper, 1868. 
Deposits — spinous rods, sometimes pierced with a few holes. Tentacles of nearly 
equal size. 
Habitat . — Chili (Semper). 
The following species are more or less incompletely known and need re- 
examination : — 
Thyone 'pulcherrima [Pentamera), Ayres, 1854 ; Semper, 1868. 
Habitat . — South Carolina (Ayres, Stunpson), North Carolina (Verrill), from South 
Carolina to Vineyard Sound (Verrill), Fort Macon (Coues and Yarrow). 
Judging from the description of Ayres, the pedicels are confined to the ambulacra, 
forming three well-defined double rows. Semper says that they are present, 
though rarely, even on the interambulacra. Anus armed with five teeth. Cal- 
careous ring composed of ten pieces, the radial with a posterior bifurcate pro- 
longation. Deposits in numerous, inseparable, perforated layers, their true shape 
not fully clear. It seems doubtful whether the species really belongs to this 
genus. 
Thyone muricata {Tr achy thy one), Studer, 1877. 
Habitat . — Kerguelen (Studer). 
This species is a true Thyone, though its pedicels run out from conical papill*. Anus 
with five teeth. Deposits — oval or triangular plates, perforated with several larger 
and some smaller holes ; they are closely crowded. 
