C. Wachsmuth—Structure of Paleozoie Crinotds. 117 
vided the food could be brought in contact with it. The large 
cilia on the inner wall of the alimentary canal, which Dr. Car- 
penter describes as being capable of producing such a power- 
ful indraught to the region of the mouth, afford, it seems to 
me, also a very satisfactory explanation ‘of the mode by which 
the transmission of food was effected in Paleozoic Crinoids. 
How much more powerful must have been the effects of these 
cilia in individuals, in which mouth and furrow were arched 
over and in which the current was unobstructed from without. 
Considering, further, that probably the covered parts of the 
food channels themselves were fringed with cilia of similar 
fanctions, it could have been of but little moment how remote: 
from the mouth the food entered. We find another most strik- 
ing example in confirmation of this supposition in Hypomene 
Sarsi Lovén, a recent Cystidian, indicating in analogy with re- 
cent nature that Crinoids had the mouth sometimes internal. 
’rof. Lovén found in the covered parts of its channels micro- 
scopic Crustacea, larval bivalyes, and other remains of the food 
of the animal, apparently taken through the open parts of the 
channels. Applying this observation to Paleozoic Crinoids it 
seems very probable that their food was taken up along the 
open parts of the arms or pinnule, and conveyed through the 
closed parts to the concealed mouth. 
Dr. Ludvig Schultze, in his excellent “ Monograph on the 
and compares these with the covered food grooves in Hypo- 
mene Sarsi, expressing the opinion, that the galleries under- 
tom and thus transformed into ducts, were food passages. 
_ Meek & Worthen describe and figure in the Illinois Geolog- 
teal Report, vol. v, from my former collection, now in the Mu- 
um of Comparative Zoology at Cambridge, several specimens 
of well-preserved digestive organs, and also an Actinocrinus pro- 
oseidialis, in which a skeleton of tubular canals proceeds from 
4 point below the central axis of the vault, to the arms. There 
are in that specimen five main tubes which bifurcate midway 
toward the arm bases, each division bifureating again, sending 
4 branch to each one of the twenty arms of that species. The 
