448 THE DEPTHS OF THE SEA. [CHAP. TX. 
calcareous lamin:e, clinging to small pieces of shell, 
grains of sand—anything which may improve the 
anchorage of the crinoid in the soft mud which is 
nearly universal at great depths. 
In Lhizocrinus the basal series of plates of the 
cup are not distinguishable. They are masked in 
a closed ring at the top of the stem; and whether 
the ring be composed of the fused basals alone, or 
of an upper stem-joint with the basals within it 
forming a ‘rosette,’ as in the calyx of Antedon, is 
a question which can only be solved by a careful 
tracing of successive stages of development. The 
first radials are likewise fused, and form the upper 
wider portion of the funnel-shaped calyx. The first 
radials are deeply excavated above for the insertion 
of the muscles and ligaments which unite them to 
the second radials by a true (or moveable) joint. 
One of the most remarkable points in connection 
with this species is, that the first radials—the first 
joints of the arm—are variable in number, some 
examples having four rays, some five, some six, and 
a very small number seven, in the following pro- 
portions. Out of seventy-five specimens examined 
by Sars, there were— 
with arms. 
— 
Or H= 
29 3? 
or) 
» 
3 ”9 ” 
» 
» 
ad ” 9 
This variability in so important a character, par- 
ticularly when associated with so great a prepon- 
derance in bulk of the vegetative over the more 
specially animal parts of the organism, must un- 
doubtedly be accepted as indicating a deterioration 
