ON THE SHETLAND CRUSTACEA,, TUNICATA, ETC. 317 



Echinod. p. 301, pi. xi. fig. 56 b, and pi. iv. figs 14 A & 14 B; Sars, 

 Middlehavets Littoral Fauna, p. 132, pi. ii. figs. 44-48 ; Oversigt af 

 Norges Ecliinodermer, p. 101 ; Alder, Trans. Tyneside Nat. Field Club, 

 vol. iv. p. 43, pi. ii. figs. 3, 4. Common, more particularly so in St. 

 Magnus Bay. 



Cucumana Hyndmanni (Thompson). Common in deep water. 



lactea (Forbes & Goodsir) = Ocnus lacteus, Forbes. British Starfishes, 



p. 2'3L, = Cucumaria lactea, Von Diiben & Koren, Ofversigt af Skandi- 

 nav. Echinod. p. 297, pi. xi. fig. 55, and pi. iv. figs. 3-7. Common. 



Thyonidium commune (Forbes & Goodsir) = Cucumaria commune, Forbes, 

 British Starfishes, p. 217 (but not Thyonidium commune, Yon Diiben & 

 Koren, Ofversigt af Skandinav. Echinod. p. 305, pi. xi. fig. 51, and pi. 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 

 Koreii in the Scandinavian species, for which 1 would propose the name 

 Thyonidium Dubeni. In T. 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. Dubeni, have only very small spicules imbedded in their substance, of 

 the same character and nearly the same form as those of Thyone fusus, 

 but of still smaller size. 



hyalinum (Forbes) = Cucumaria hycdina, Forbes, British Starfishes, 



p. 221, = Thyonidium pellucidum, Von Diiben & Koren, Ofversigt af 

 Skandinav. Echinod. p. 303, pi. xi. fig. 57, and pi. iv. figs. 15-17 (but 

 not Holothuria pellucidci, Vahl, Zool. Dan. pi. cxxxv., which is Chirodota 

 pellucida, Sars, Oversigt af Norges Echinod. p. 124, pis. xiv.-xvi., = Chi- 

 rodota Icevis, Liitken, Gronl. Echinod. p. 16). Not rare on the Haaf ; 

 also in St. Magnus Bay, and the Whalsey Haddock -ground. 



Thy one fusus (Miiller) = Holothuria fusus, Miiller, Zool. Dan. pi. x. figs. 5, 6, 

 = Holothuria papillosa, Abildgaard, Zool. Dan. pi. cviii. fig. 5, = Thy one 

 papillosa, Forbes, British Starfishes, p. 233, = T hy one fusus, Von Diiben 

 & Koren, Ofversigt af Skandinav. Echinod. p. 308, pi. xi. fig. 52, and 

 pi. v. figs. 42-48. 



Far from common ; Whalsey Skerries Haddock-ground, and St. Mag- 

 nus Bay. 



raphanus, Von Diiben & Koren, Ofversigt af S.kandinav. Echinod. p. 311, 



pi. xi. figs. 58, 59, and pi. 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 



