C. Wachsmuth—Structure of Paleozote Orinoids. 189 
being comparatively of large size, have generally but two pri- 
mary arms, and consequently for each ray but one radial dome 
plate which is here placed at some distance from the arm bases. 
tinguishing many genera. In Agaricocrinus, all apical and 
plates to the subradials (the two smaller plates, separated by 
the anus forming together one large one), which on the other 
hand were undoubtedly the first developed parts of the dorsal 
side, and the parts which are the most highly developed in the 
Cystideans. 
zoic Crinoids that are known. There are some few genera, as 
for instance Hucalyptocrinus, with a very peculiar superstructure 
at the ventral side, whose affinities I have not been able to de- 
termine. There is the genus Calceocrinus which differs so widely 
from all other known Crinoids by its distinct bilateral symme- 
try and unique structure, that it forms evidently a very dis- 
tinct group pe itself. There may be still others, differing in 
