Massy — The Holothurioidea of the Coasts of Ireland. 41 



Irish National Museum, and their spicula, though partly dissolved, and 

 their external appearance prove them to be the same species which is here 

 referred to B. Tizardi. It will be remembered that Bell (1892, A, p. 51) 

 expressed much doubt as to the correctness of Sladen's identification. 

 Ostergren (1902, p. 6) is of opinion that up to the present B. natans has only 

 been observed with certainty on the west coast of Norway from 60° to 69° 

 N. latitude. The specimens from the three hauls given above, as well as 

 those not preserved, were all entered in the log-books as " squashy red 

 Holothurians." In alcohol they are cream colour above and deep buff on 

 the ventral surface. Owing to their very slimy skin, they are frequently 

 thickly covered with grey sponge spicula, fish scales, &c. ; a mounted portion 

 of the perisome of one specimen displayed (mixed up with its own deposits) 

 a number of wheel-shaped deposits of Benthogone rosea, Koehler, which 

 happened to be abundant in the same haul. The spicula, as in the descrip- 

 tion of the type, consist of a cross, or, more rarely, a star, with enlarged ends 

 pierced with one or more holes. The enlarged ends are often connected so 

 as to form an annular disc. As in B. jxitagiatus, Fisher (1907, p. 689), 

 annular discs are very numerous on the ventral surface. Eight cross-beams 

 are usually present in the spire of the tables of the papillae. These tables 

 have the disc much reduced, and rarely annular, as far as examined, 'i'he 

 tables of the pedicels have an annular disc, and a short spire of two cross- 

 beams. They are further supported by slightly curved spinose rods and a 

 terminal plate, which is sometimes split up into a few small jagged plates. 

 As in B. patagiatus {op. cit., pp. 688-9), C-shaped spicula are very abundant 

 in the walls of the anus, and on the gonadial tubes, but appear to be absent 

 from the outer integument. B. bipartitus, Herouard (1912, p. 4), agrees with 

 the present specimens in the absence of external C-shaped spicula, but it 

 has pedicels along the entire median line of the ventral surface, whereas in 

 our specimens this part is always defined by a deep groove, in which no 

 pedicels were detected. B. reptans (Perrier, 1902, p. 352) resembles our 

 examples in the red colour of body and shape of deposits, but it has far 

 more dorsal papillae. Koehler describes the colour of B. Tizardi as grey, 

 and Perrier supposes that this description refers to the living animal, since 

 Koehler's other descriptions were based on such. Probably variations in 

 colour occur according to the conditions of environment, and a pale- coloured 

 form, coated with grey ooze and pearly fish scales, could only be described as 

 grey. 



Bidribution.—'Fa.ioe Channel, 530-555 fms. (Theel, 1882). Bay of Biscay, 

 355-710 fms. (Koehler, 1896). West coast of Morocco, Sahara, and Senegal 

 (Perrier, 1902). South Norway (Ostergren, 1902). Japan (Ohshima, 1915). 



