In one case only have I found any irregularity. The eighth whorl has its two regular
cirri like the sixth, together with an additional one which therefore comes to be on the


REPORT ON THE CRINOIDEA. 320


same side of the stem as the third cirrus in the seventh whorl. But the ninth whorl has
only two cirri instead of three; and is the beginning of a new cycle; for the tenth whorl
is not.like the sixth with only two cirri, but resembles the irregular eighth one with
three. In the same way the eleventh whorl is like the ninth and not the seventh,
and so on.
