REPORT ON THE CRINOIDEA. 365 



of about forty joiuts, some of which (after the short and wide ones at the base) are 

 longer than broad. The dorsal edge of the middle joints Ls slightly serrate, but the later 

 ones become almost smooth. Interarticular pores end about the ninth node. 



Basals pentagonal and forming a closed ring, but very convex in the centre, so as to 

 appear like rhomboidal knobs resting on the interradial ridges of the stem. Radials six, 

 very convex, the second and fourth syzygies. Rays well separated laterally, and divide 

 four times. Arms twelve or more to the ray, slightly serrate in the medio-dorsal line, 

 especially in the lower divisions. Primaries of six or eight (rarely ten) joints ; second- 

 aries of eight to fourteen palmars ; tertiaries of sixteen to twenty-eight joints. The 

 rliird joint after each axillary is a syzygy, and the next syzygy in the free arms is 

 anywhere between the tenth and twenty-fourth joints ; after which the syzygies follow at 

 intervals of five to fourteen joints. 



The radial pinnules, especially the first one, mostly have wide and massive basal 

 joints with thickened edges ; but the middle joints are more compressed and the terminal 

 ones slender. The distichal pinnules are also stout and composed of large joints ; but 

 the following ones consist of compressed and more elongated joints, the first two of which 

 are considerably wider than the rest until some little way beyond the last axillary. 



The disk is covered with numerous small plates, which are mucli smaller and more 

 closely set in the anal interradius than elsewhere. Brachial amljulacra above the arm- 

 grooves, and protected by irregular plates from which the covering plates and large 

 pointed side plates are developed on the pinnules. 



Colour — of a uniform dusky purple when fresh (Moseley); greyish-white in 

 spirit. 



Locality. — Station 170a, July 14, 1874 ; near the Kermadec Islands; lat. 29° 45' S., 

 long. 178° 11' W.; 630 fathoms; volcanic mud; bottom temperature, 39°"5 F. 



Remarks. — Three examples of this elegant little species seem to have been obtained 

 by the Challenger. One of them is cj^uite young (PL LI. fig. 1), while the other two were 

 in a much mutilated condition. The dissected calyx figured on PI. L. figs. 5-18 appears 

 to belong to the fragment represented on fig. 1 of the same Plate. It is certainly not 

 the same as that of which the disk is shown in fig. 2. This last and a few detached arms 

 have served as the basis of the foregoing description. The only species with which 

 Metacrinus nodosus is liable to l)e confused is the little Metacrinusi costatus from ofl" the 

 Meangis Islands (Station 214). For Metacrinus loyvilUi, which also has six radials and 

 about the same number of internodal joints, is altogether much larger and more robust. 

 But it has a smaller number of arms than either Metacrinus costatus or Metacrimis 

 nodostts. The difi"erence between these two last lies chiefly in the characters of the stem, 

 both of them having twelve or more arms on the ray, o-ndng to the presence of axdlaries 

 on the outermost of each set of four tertiary arms, as well as on some of the inner ones 

 occasionally. The pinnules are generally similar in the two types, and the peculiar 



