376 Wachsmuth and Springer—Paleocrinoidea. 
In Joerinus (fig. 4), the arrangement is somewhat like that 
of Hoplocrinus. The right posterior radial is almost as small 
as in that genus, but in place of occupying the corner only, it 
extends over the whole width of the azygous plate, from which 
it is separated by a horizontal suture. There is no special anal 
plate, the ventral tube rests upon the left sloping side of the 
radial, and as the tube has no connection with the azygous 
plate, we suggest that possibly the radial may embrace an 
undivided anal pi 
In the preéminently Sub-carboniferous genus Poteriocrmus 
(fig. 8), we find an azygous plate, but this is pushed out still 
more from beneath the radial than in Homocrinus,; its form 
is pentagonal, owing to an additional plate, which rests upon 
its upper truneate side. This plate, which is hexagonal and 
best known as the third anal piece, is actually a plate of the 
ventral tube incorporated within the calyx. ‘The anal plate, 
which is smaller than in the two preceding genera, is hexa- 
gonal, and alternately arranged with the azygous plate and the 
plate above. 
In the typical Lipachycrinus (fig. 9), the case is almost the 
same as in Poteriocrinus, only the azygous plate is compara 
* In Revision I, pp. 65-75, we considered the combined right posterior radial 
and the azygous plate in Dendrocrinus, which in their position and proportions 
—- the right posterior radial in Cyathocrinus, to be a compound radial ree 
erinus, Homocrinus, and in the Cyathocrinidse generally, was a modified radial, 
and also that the anal tube, possibly, had been developed from an arm. Upoo 
these points we were evidently in error. : 
