ON THE SHETLAND CRUSTACEA, TUNICATA, ETC. 317 
Echinod. p. 301, pl. xi. fig. 56 5, and pl. iv. figs 14A & 14B; Sars, 
Middlehavets Littoral Fauna, p. 132, pl. ii. figs. 44-48; Oversigt af 
Norges Echinodermer, p. 101; Alder, Trans. Tyneside Nat. Field Club, 
vol. iv. p. 43, pl. ii. figs. 3, 4. Common, more particularly so in St. 
Magnus Bay. 
Cucumaria Hyndmanni (Thompson). Common in deep water. 
lactea (Forbes & Goodsir) =Ocnus lacteus, Forbes, British Starfishes, 
p. 231,=Cucumaria lactea, Von Diiben & Koren, Ofversigt af Skandi- 
nav. Echinod. p. 297, pl. xi. fig. 55, and pl. iv. figs. 3-7. Common. 
Thyonidium commune (Forbes & Goodsir)=Cucumaria commune, Forbes, 
British Starfishes, p. 217 (but not Thyonidium commune, Von Diiben & 
Koren, Ofversigt af Skandinay. Echinod. p. 305, pl. xi. fig. 51, and pl. iv. 
figs. 18-23). 
A single specimen in St. Magnus Bay, 1867. In this species there 
are spicules present in the skin, and those of the tentacles are of entirely 
different structure from those described and figured by Von Diiben and 
Koren in the Scandinavian species, for which I would propose the name 
Thyonidium Diibeni. In 7. commune the skin is covered with table- 
formed spicules, which have the lid round, or nearly round, with an un- 
usually even rim, and the perforations numerous, very small and round; 
the legs are four, connected at the foot, and each there divided. The 
tentacles, instead of being covered with spicula of considerable size, as in 
T. Diibeni, have only very small spicules imbedded in their substance, of 
the same character and nearly the same form as those of T’hyone fusus, 
but of still smaller size. 
— hyalinum (Forbes) = Cucumaria hyalina, Forbes, British Starfishes, 
p. 221, =Thyonidium pellucidum, Von Diiben & Koren, Ofversigt af 
Skandinay. Echinod. p. 303, pl. xi. fig. 57, and pl. iv. figs. 15-17 (but 
not Holothuria pellucida, Vahl, Zool. Dan. pl. exxxv., which is Chirodota 
pellucida, Sars, Oversigt af Norges Echinod. p. 124, pls. xiv.—xvi., = Chi- 
rodota levis, Liitken, Gronl. Echinod. p. 16). Not rare on the Haaf; 
also in St. Magnus Bay, and the Whalsey Haddock-ground. 
Thyone fusus (Miller) = Holothuria fusus, Miller, Zool. Dan. pl. x. figs. 5, 6, 
= Holothuria papillosa, Abildgaard, Zool. Dan. pl. eviii. fig. 5, = Thyone 
papillosa, Forbes, British Starfishes, p. 233, =Zhyone fusus, Von Ditben 
& Koren, Ofversigt af Skandinay. Echinod. p. 308, pl. xi. fig. 52, and 
pl. v. figs. 42-48. 
Far from common ; Whalsey Skerries Haddock-ground, and St. Mag- 
nus Bay. 
raphanus, Von Diiben & Koren, Ofversigt af Skandinav. Echinod. p. 311, 
pl. xi. figs. 58, 59, and pl. v. figs. 49-55; Sars, Oversigt af Norges 
Echinod. p. 112. 
Common in deep water. 
elegans, n. sp. Length 1-2 inches. Body smooth; skin thin, very de- 
licate, totally devoid of all calcareous imbedded spicula ; feet numerous, 
but not crowded, scattered all over the body, their sides without spicula, 
but a large round spiculum at the extremity. This spiculum has 
round perforations in the centre, exterior to these a circle of large ra- 
diating wedge-shaped openings, the spaces between them very narrow ; 
and exterior to these again, and close within the edge, a few small per- 
forations, the length of which is in the opposite direction to that of the 
radiating openings, each of them forming a minute segment of a semi- 
circle. Tentacula 10 (8 long and 2 very short), completely clothed in a 
