ECHINODERMATA — CLARK. 563 



Calcareous ring remarkably wide, with conspicuous anterior pro- 

 jections and posterior radial prolongations ; entire length of 

 radial piece more than 5 mm.; posterior prolongation, 2 mm., 

 notched for nearly its whole length. Polian vessel, stone-canal,' 

 and respiratory trees not observed. Calcareous deposits in body- 

 wall very abundant, making the surface rough to the touch ; 

 these deposits are rather stout tables (PI. Iviii, figs. 22-26) with 

 more or less irregular disc (often -25 mm, in diameter) and high, 

 rough, pointed spire, made up of three rods; disc usually with 

 two or three principal holes, and one or more irregular or incom- 

 pletely closed ones on or near margin ; spire with seven or eight 

 cross-bars; in caudal appendage, tables (PI. Iviii, figs. 27-30) much 

 smaller and more regular, with five — ten perforations in disc, each 

 end of which is drawn out into a short, smooth, blunt rod, and a 

 low triangular spire with only three or four cross-bars. Most of 

 the tables in the body are more or less discoloured, apparently a 

 step towards being transformed into phosphatic bodies, which are 

 excessively numerous, and deeply coloured. Oral disc and 

 caudal appendage very light grey ; body almost uniform, deep 

 purplish-red, showing under a lens a fine variegation with light 

 grey lines and dots. 



Three specimens from Station 46. Ofi" Jibbon, 50-66 fathoms ; 

 nmd and abattoir refuse. 



It is certainly remarkable that Molpadids were taken only at 

 this one Station, where perhaps the " abattoir refuse " may prove 

 .a source of food-supply to these mud-loving and mud-eating 

 animals. But it is even more remarkable that the six specimens 

 taken should be divided equally between two quite distinct 

 species, neither of which has been described hitherto. There 

 appears to be no doubt of their distinctness, for none of the 

 specimens shows the least tendency towards intergrading charac- 

 ters. The difterence between the two .species in their calcareous 

 rings is almost as striking as the difference in their calcareous 

 deposits. While both species approach the common Pacific species 

 intermedia in their general appearance, the calcareous tables are 

 so different from those of that species that they cannot be con- 

 sidered very closely allied to it. 



The discovery of these two new species necessitates the modifi- 

 cation of the key to the .species of Molpadia, published early last 

 year*^ and subsequently altered*" to admit a new species from 

 .Japan. The first part of this key will now read as follows : — 



*5Clark— Apodous Holothurians, 1908, p. 158. 

 46Clark— Bull. Mus. Comp. Zool., 11., 1908, p. 311. 



