Wachsmuth aud Springer—Paleocrinoidea. 377 
tively more developed. This is somewhat remarkable, as 
Lupachycrinus is one of the latest known forms of the Palzo- 
crinoidea, and, apparently even within the limits of this genus, 
or contemporaneously with it, we find all the gradations, from 
the most extravagantly developed anal side to its simplest. 
forms. Aside from the irregular symmetry, which evidently 
Tepresents a retrogression, the species show in all respects that 
they belong to one of the highest types of the group, and par- 
Ucularly in their mode of articulation they are fully up to the 
urassic Neocrinidea. . 
Eupachyerinus, but has been very properly separated by Dr. 
White under the name Cerdocrinus (Contributions to Paleeon- 
ual disappearance of this plate in the growing animal is 
tepresented paleontologically by the modifications which take 
oplocrinus. We further hold that the 
Special anal plate in Hybocrinus is the first step toward a 
plated tube which in that genus is reduced to its minimum size, 
consisting of only a single plate. The diminuitive tube pos- 
Sessed in its crenulated, rhomb-like structure an organization 
Similar to that of the later genera in their large porous sac 
composed of numerous plates, and it is probable that both 
structures performed the same functions, and these may have 
been identical with those of the rhombs in the Cystidea. 
