368 THE VOYAGE OF H.M.S. CHALLENGER. 
The following pinnules gradually decrease in size and their jomts become more flattened, 
the two lowest retaining a certain amount of preponderance, being often much broader 
than their successors. Beyond the distichal axillary, however, this is almost entirely 
lost, the pinnules tapering gradually and symmetrically from the basal joints, which are 
not specially distinguished in any way. 
The disk (so far as it is visible) is covered with numerous small plates which are not, 
however, set perfectly close to one another. Brachial ambulacra but little above the 
arm-grooves, and bordered by somewhat forked plates from which the large side plates 
of the pinnule-ambulacra are soon developed. 
Colour in spirit, greyish-white, with a tinge of brown at the tips of the cirri, arms, 
and pinnules. 
Locality.—Station 209, January 22, 1875; lat. 10° 14’ N., long. 123° 54’ E.; 
95 fathoms; blue mud; bottom temperature, 71° F. One specimen. 
Remarks.—This species is readily distinguished from the three preceding ones in the 
same group by the greater length of the internodes in the stem. Their component 
joints (Pl. LIL. fig. 3) are altogether different from the lobate joints of Metacrinus costatus 
(Pl. XLIX. fig. 4) and of Metacrinus nodosus (Pl. LI. fig. 10), having the same 
pentagonal form and horizontal ridges as Metacrinus wyvillii (Pl. XLVI. fig. 4). 
The nodal and infra-nodal joints, however, are entirely different from those of this 
type, in which the infra-nodals are distinctly incised by the cirrus-sockets, so that 
their syzygial surface is lobate (Pl. XLVII. fig. 3) and not pentagonal as in Metacrinus 
interruptus. Another character in which this species differs very markedly from the three 
previously considered is the small size of the basal jomts on the palmar and lower 
brachial pinnules. 
The type to which on the whole Metacrinus interruptus appears to be most closely 
allied is the as yet undescribed specimen dredged by the “Vega” at a depth of 65 
fathoms in the Bay of Yedo. By the kind permission of Prof. 8. Lovén, who was good 
enough to send me some fragments of its stem, and also to allow my friend Mr. W. Percy 
Sladen to examine it on my behalf, I am able to say that it appears to be totally different 
from Metacrinus interruptus. The stem-joints that I have seen have a smaller diameter 
and a greater height both relatively and absolutely than those of that species; and they 
are not provided with horizontal ridges, but only with faint tubercles at the angles, and 
still less distinct ones at the sides. In the character of the nodal joints, however, and in 
the absence of any extension of the cirrus-socket down on to the infra-nodals, the two 
types are very closely similar, as they are in the length of the internodes. There seem 
to be several other points of difference between Metacrinus interruptus and the “ Vega” 
specimen, such, for example, as the length of the primary arms and the characters of the 
pinnules. These will doubtless be explained more fully when the “ Vega” Crinoids are 
described - and I have therefore done no more than assign to the Japanese form a place 
