144 RECENT UNSTALKED CRINOIDS 
decrease in length so that the last ten or eleven before 
the penultimate are twice as broad as long; the fourth 
and following segments have the distal dorsal edge pro- 
jecting slightly, this on the short terminal segments be- 
coming a prominent median carination with a convex crest 
ocenpying the entire dorsal surface of the segment. 
The ends of the basal rays are rather prominent as 
rounded triangular areas in the angles of the calyx; the 
radials are rather prominent; the median dorsal line, which 
is about as long as the lateral edge beyond the basal rays, 
makes but a very slight angle with the horizontal; the 
IBr, are four times as broad as long in the median line, 
the lateral edges being from one third to one half again 
as long as the median length; the lateral edges slope 
strongly inward, continuing in the same direction as the 
lateral upturned borders of the radials; the middle third 
of the proximal border is slightly convex; the distal border 
is deeply incised by a posterior rounded projection from 
the axillary; the distal halves of the lateral edges bear a 
prominent tubercular process; the axillaries are about as 
broad as long, the anterior sides making a right angle 
with each other, the anterior angle being slightly produced ; 
a strongly rounded posterior process extends backward to 
about the same distance below the line connecting the 
lateral angles as the apex of the anterior angle is above 
it; there is a prominent lateral tubercular process just 
below the lateral angles; the distal edges, like the lateral 
portion of the distal edge of the IBr,, have an exceed- 
ingly finely spinous border; the synarthrial tubercles are 
broadly rounded, but rather prominent. 
The ten arms are mm. long; the first brachial is 
short, three times as long exteriorly as interiorly, slightly 
longer in the median line than interiorly; the inner edges 
are in apposition; the outer edges are slightly concave; 
the distal inner angles have an indication of tubercles 
resembling those on the distal outer part of the side of 
the IBr,; these tubercles on the ossicles of the IBr series 
Notes from the Leyden Museum, Vol. XXXIV. 
