178 THE VOYAGE OF H.M.S. CHALLENGER. 



tuberosa and its Pentacrinoid were found associated at Station 210 with Antedon distincta. 

 But these facts afford us no grounds for asserting that Antedon rosacea and Antedon 

 phalangium, Antedon porrecta and Antedon midtispina, Antedon tuberosa and Antedon 

 distincta are respectively identical types. 



Thus then it appears to me that neither of Fischer's reasons for believing in the 

 specific identity of Antedon tenella and Antedon prolixa has any probative value ; and 

 I see no necessity, therefore, for reducing Antedon prolixa, Sladen, to the rank of a 

 synonym as Fischer has done. (See the footnotes on p. 175.) 



One example of the Pentacrinoid larva of Antedon tenella was dredged by the " Porcu- 

 pine " in the Faeroe Channel. It is a trifle more advanced than that represented by Sars 

 in figs. 9 and 11 on Tab. V. of his classical " Memoires." The arms are longer, with no 

 pinnule below the eighth joint. There is, however, but one cirrus, which seems to be the 

 only one as yet developed, though it is of considerable size, reaching up to the level of 

 the radial axillaries on the opposite side of the larva to that shown in the figure (PI. XIY. 

 fig. 4). The stem is attached by a slight calcareous expansion at about its thirty-fifth 

 joint to one of the rays of a Rhabdammina abyssorum ; and it then passes on to form 

 two other spreading attachments, with radicular branches sprouting from them over a 

 portion of a tubular Hydroid. 



Two of the " Triton " specimens of Antedon tenella from the Fseroe Channel were 

 infested by Myzostoma carpenteri, the only species of Myzostoma yet found in association 

 with this Comatulid. 



4. Antedon exigua, n. sp. (PI. XXXII. figs. 1-4). 

 Specific formula — A.-r. 



Centro-dorsal hemispherical, almost covered by some fifty cirri of about twenty joints. 

 The lowest of these are much longer than wide, but the distal joints are short and 

 compressed. 



First radials nearly or quite invisible ; the second short, almost concealed in the 

 middle line by the blunt hinder angles of the axillaries. These are broadly rhombic, 

 with a sharp clavicular process, and extend laterally beyond the second radials. The 

 surfaces of both joints fall away laterally from their medio-dorsal line. Ten arms ; the 

 first brachials with very long outer sides but a short centre and inner sides, the proximal 

 ends of which just meet their fellows above the clavicular. They are raised in the median 

 line to meet the sharp hinder angles of the large quadrate second brachials. Arm-joints 

 oblong till the second syzygy, with more or less distinct, alternating, backward processes ; 

 the following joints subtriangular, gradually becoming obliquely quadrate. Syzygies in 

 the third, eighth, and twelfth brachials, and then at intervals of two joints. 



