A New Cystocrinoidean Species. — Sardeson, 
273 
The following diagram may represent crudely the sug- 
gested relationships : 
C/u4.tocrinozdEo.n cin £estor, A 
Ca-ttoerinus 
An eSSt)- a. Z tyT>e S 
I 
Strophe erinwa 
"Porocrinus 
hiioni,a.locrimiS 
Cciro-ljocrinu.$ 
•^f, J i, rs, az . 
MonoeyeJioa A. 
Dicuclica, 
MonoeyeliaaB. 
(^^■).^s. r-f. 
Regarding the stem of Strophocrinus, there is nothing 
peculiar in its five column segments. It admits Neumayr's 
interpretation that this structure is pre-crinoidean, while it does 
not seem to justify the great emphasis that has been placed by 
authorities on Crinoidea, on the relation of the sutures and 
furrows of the column to the infrabasals and "basals." The 
relation may be here interpreted as follows : In the first place, 
basals and infrabasals are referable to hexagonal form. The 
anterior basal (fig. 12, pi. xii) is hexagonal, but approaches 
a pentagon in dimension ; ac= ab =radius of hexagon. The 
lower two sides dd are conspicuously shortened, hence the 
pentagonal form. A quadrangular anterior infrabasal, fig. 13, 
has a similar relation to a hexagon ; ac ^ ab radius of hexagon, 
and the lower part of the quadrangle has bb be, which coin- 
cides in proportion with bb-be in fig. 12. Compared to a 
hexagon and to a pentagonal basal, this infrabasal is a third 
stage in reduction. If we view the infrabasals as modified 
pentagonal or hexagonal plates, then we must account for 
