234 REVIEWS 
then being supported partly by the basals and partly by the infraradial; 
and that in Carabocrinus, Botryocrinus, and allied forms the said ossi- 
cle has sunk to a line with the radials. Mr. Bather evidently has con- 
founded here plates which are morphologically quite distinct. In the 
above genera the plate under consideration is represented only by Den- 
drocrinus, Carabocrinus, and Botrycrinus. The piece to which refer- 
ence is made in Iocrinus, Heterocrinus and Hybocrinus is a plate of 
the vental sac, as is conclusively proven by Dendrocrinus, otherwise it 
must be admitted that the plate would be represented twice in the same 
specimen, by the true anal plate which rests upon the basals, and by 
the tube plate (of locrinus) which is supported by the supraradial. The 
anal area of Dendrocrinus is like that of Poteriocrinus, only that the 
superradial of the former does not move away from the inferradial, as 
it does in the latter. This is not necessary in a form like Dendro- 
_ crinus in which the arm-facets occupy a comparatively small part of the 
radials and leave ample space for the support of the tube. ‘In the 
Poteriocrinide, however, in which the upper surface of the radials is 
taken up completely by the costals, the foundation of the tube is not 
adequate to the width and the deficiency is manifestly made up by a 
shifting of the superradial and the introduction of another plate for 
the support of the tube. 
In the anal interradius, as it appears in the various families of the 
Camerata, a close agreement is found between the anal plate (x) and 
the tube plates of the Fistulata on one side, and the anal plate and 
interradials on the other. Admitting this, a more satisfactory expla- 
nation of the anal plates of the Fistulata is reached than that given 
by Mr. Bather whose views do not cover the Camerata ; besides being 
based upon premises which appear tobe entirely hypothetical. If it 
were true that Bather’s plate x of Iocrinus passed down in later forms 
from above the superradial to the basals, it would certainly require a 
partial revolution of the whole tube; but this is clearly disproved by 
the structure itself, which throughout its full length is composed of 
hexangular pieces, regularly arranged in longitudinal rows. Bather 
also regards the anals of the Camerata as morphologically distinct from 
those of the Fistulata, while there actually seems to be good grounds 
for believing that the plate x of the latter is homologous with the first 
anal in the Camerata, and also with the anal which for a time occurs in 
the larva of the Comatule ; but that the Camerata have no radi-anal 
for the simple reason that they have no compound radials. The anals 
