146 CATALOGUE OF THE ECHINODEKMATA OF 



are excessively small, the longest being barely T oVo of an inch 

 in length. Fig. 18 represents a portion of a sucker tip, which 

 is a flat plate of a circular form about toW of an inch in dia- 

 meter. It will be seen the edge of the spicule figured is irregu- 

 lar in outline, the deposit having run into a number of pointed 

 projections differing in this respect from the body spicules. 



Genus. THYONE, {Okm.) 



Thyone fusus, Mutter. Common Thyone. PL II., figs. 19-40. 

 Holothuria fusus, Muller. Zool. Dan. PI. X., figs. 5, 6. 

 Thyone papillosa, Forbes. Brit. Starfishes (1841), p. 233. 



Cullercoats, from the boats, not uncommon, J. A. 



This is by far the commonest species on our coast, several 

 specimens having been taken on the various stations where col- 

 lecting has been pursued, it may be considered to occur all along 

 our shores in deep water, usually on a rough bottom. It is a 

 well marked form, not readily mistaken for any other species 

 found with us. Its spicules also are usually readily distinguish- 

 able ; figs. 30-39 representing those found in the skin of the 

 body; 19-29 those from the suckers; 40 the plate from a sucker 

 tip. The length of the body spicules is about totto- to -roVo- of 

 an inch; those from the suckers about -reVo- long by xoVtj to 

 two broad ; the diameter of the sucker disc (fig. 22) totto-- 



Thyone eaphanus (Diiben and Koren). PL III., figs. 22-30. 



Thyone raphanus, Diiben and Koren, EchL, p. 311. 

 PL V., figs. 49-55 ; and PL XL, fig. 58. 



Thyone raphanus, Thompson. Ann. Nat. Hist., 1847. 

 Vol. XX., p. 176. 



Rather rare on the Northumberland and Durham coasts, G. H. 



Our captures of this species have been limited to three or four 

 specimens, all of moderate dimensions. The spicules are of a 

 very distinct character, consisting of large flat plates of irregular 

 outline, perforated by a varying number of circular or slightly 



