1884.] PROF. F. J. BKLL ON HOLOTHURIA NIGRA. 373 



of Natural History,' vol. xv. (1845). In a note on Irish Echino- 

 dermata, read to the Dublin Natural-History Society, Prof. Kinahan 

 mentions by name " Cucumaria niger, Couch," 1 as having been 

 taken on the west coast of Ireland (Natural History Rev. vol. vi. 

 p. 369) ; in the succeeding year (cf. op. cit. vol. vii. p. 394) Mr. 

 Foot has a brief note on the habits of what he calls " H. niger." 



Finally, Prof. Moseley has under his care a specimen in the Uni- 

 versity Museum at Oxford, which bears the name of Ilolothuria 

 nigra, and is said to have come from the Scilly Islands. 



The collection of the British Museum contains five specimens 

 which appear to me to be referable to the species figured by Peach 

 but never yet so described as to be, with certainty, recognized by 

 the systematic zoologist. 



The specific characters by which it may be distinguished appear to 

 be : — Suckers almost entirely'confined to the trivial surface ; tentacles 

 twenty; body elongated ; integument very soft. Colour (in spirit) more 

 or less completely black ; in life the lower surface and " the thorn- 

 like appendage on the back" are stated to be of a light green colour. 

 Body-wall rather thick. Calcareous spicules rare ; the only forms 

 observed were perforated with four large holes, somewhat as in 

 Thyone fusus (cf. Diiben and Koren, Vetensk. Akad. Handlingar, 

 1844, pi. v. fig. 42). The oesophageal annularia of moderate size; 

 radials and interradials subequal, longest along their middle line, 

 which forms a well-marked, rather broad keel. Polian vesicle large. 

 The Cuvierian organs packed into a large compact mass. 



Measurements : — 



Length 120 110 105 



Greatest breadth . . 3/ 4 40 



The following observations may be made on the just enunciated 

 specific characters. Though the creature has been called "Nigger " 

 by the fisherman, and nigra, by the naturalist, it does, as Peach tells 

 us, vary in colour, being " all shades, from sienna to rose-colour 

 and delicate pink." The suckers do not, in spirit-specimens, appear 

 to be arranged in definite rows. They are rather thickly scattered 

 over the whole of the trivial surface ; at any rate, Peach is in error 

 in considering that this creature is remarkable for the possession of 

 four rows of suckers. From Peach's illustration it would appear 

 that the dorsal papilla}, and especially those at. the sides of the body, 

 are much more prominent in living than in preserved specimens. 



In the description of the pharyngeal ossicles I have adopted the 

 nomenclature proposed by Prof. Moseley, in his description of a 

 remarkable Holothurian pharynx a ; here annularia only, and no 

 pharyngealia, are developed. The scarcity of calcareous spicules was 

 to be expected as soon as one knew that " on exposure to air they 

 lose their tenacity and crumble to pieces ; " but, on the other hand, 



1 The addition of the name of Couch must be an error ; I find no reference 

 to the species in the ' Cornish Fauna.' 



2 Q. J. M. S. xxiv. (1884) p. 255. 



