Bd. VI: 8) THE CRINOIDEA. S 



articulations a little thickened; the terminal joints are coarsely spinous on their dorsal 

 side (PI. II, Fig. 4; textfig. 3 c). 



Sacculi few and very inconspicuous, irregularly arranged. 



The ambulacral grooves are heavily plated, with regularly arranged side- and 

 coverplates, the side plates being much the larger; when closed they form a roof 

 over the ambulacral furrow, the cover plates interlacing (PI. Ill, Figs, i, 3 — 4; text- 

 fig. 4); the latter lie at an angle with the side plates. Also on the pinnules the side 

 and cover plates are well developed, continuing until the end of the furrow. There 

 are 4 — 5 side plates to each pinnula joint (PI. II, Fig. 4). 



The mouth is central. Anal tube very conspicuous, near the oral corner of the 

 interradius; the edge of the opening generally distinctly lobed. 



The perisome with numerous, thick plates, which form a close pavement between 

 the armbases (PI. II, Fig. i), while farther up the sides of the disk they are more 

 sparse. On the ventral side of the disk they are especially 

 prominent in the anal interradius and on the basal part 

 of the anal cone (PL I. Fig. i). Among these there is 

 generally one very conspicuous plate, about twice or more 

 the size of the other plates. There can be no doubt that 

 this is the anal plate, which accordingly persists through- 

 out life in this form.' Also in the oral corner of each 

 interradius a fairly conspicuous plate may be found, which 

 evidently represents the oral; it is, however, not quite 

 constant, the orals being thus less perfectly retained than F'S- 5- -"^ piece of the ventral 



side of the intestine of Xotocri- 

 the anal plate. »,„ wn/Zx, showing the folds. ' ,. 



Most of the specimens are reddish coloured at the 

 base of the centrodorsal ; the cirri are white, the arms straw-coloured. There is no 

 information as to the color in life. 



This is a very robust species of a fair size, as may be seen from the figures on 

 PI. I, which are all in natural size. It was dredged in one locality only, 64 20' S. 

 56' 38' W., 150 m. (station 5); 15 specimens. 



The anatomy of this species is of more than general interest, aftbrding some 

 features which are quite unique among Crinoids, so far as known. 



The walls of the intestine are greatly folded, a complete labyrinth of folds ap- 

 pearing on removal of the skin of the ventral side of the disk (Fig. 5); the folds are 

 not confined to the ventral side, although more strongly developed here. A reticulate 



' It is purposely that I write -anal plate», not »radianal«, because I do not feel quite convinced of 

 the homology of the anal plate of Comatulids with the radianal of older Crinoids, as maintained by A, H. 

 Cl.\rk. But 1 cannot enter on a discussion of this question here. 



