or 
« 
RHODOCRINID_E. Z 
bo 
from five to seven “long pendulous cilia”? bearing delicate pinnules. The 
pinnulated “ cilia” they afterwards refer with a query to arms. 
Hall in 1860, without making any comparison with Goniasteroidocrinus, 
described under the new name Zrematocrinus, a number of species from the 
Subcarboniferous, of undoubted generic identity with Lyon’s species. He 
also regarded the upper appendages as arms, but doubted if they could have 
performed the functions of arms. He further suggested that probably the 
“foramina” above the secondary radials served for the protrusion of “ fleshy 
> 
arms or tentacles.” However, a year or two later he described his 7remato- 
crinus spinigerus with “ summit arms” and “ true arms.” 
In 1865, Rofe, who apparently was not acquainted with the writings 
of Lyon and Hall, while discussing certain morphological questions, asserted 
that Phillips’ species of Gidbertsocrmus “are undoubtedly Rhodocriu.’ He 
also stated that Rhodocrinus differs from most of the other Crinoids “in the 
form of the arms and in the position of the ovarian apertures,” and that 
“the arms have no grooves on the upper side, but are cylindrical, with a 
tubular canal through the axis, and the ovarian openings placed immediately 
under the base of the arms.” In reply to Billings’ supposition that the 
upper appendages might possibly be spines, he said: “ their articulated struc- 
ture, and the passage through the axis forbid the idea of their being 
spines.” 
Meek and Worthen, in 1866,* discriminated between Gilbertsocrinus and 
Gowasteroidocrinus ; making the latter a section of the former.  Gilbertsocri- 
nus was said by them to have the “ pseudo-ambulacral appendages” located 
directly over the interdistichal spaces, and Gonasteroidocrinus over the inter- 
radial ones; and they stated that these structures are not arms, that they 
“differ essentially from all appendages of the body in any known Crinoid, 
and seem to bear somewhat the same relations to the body, that the side 
branches of the column of Pentacrinus and many Palseozoic Crinoids do to the 
column itself.” The “true arms,” they say, connect with the calyx at 
the lower openings, which Hall described ~as foramina in Tvrematocrinus. 
They gave a description and good figures both of the true arms and the 
appendages, 
Grenfell, in 1875, defined Gilbertsoerinus as follows: “ Basals five; sub- 
radials five ; radials three ; brachials several, generally irregular ;_ the 
second brachial channelled at top, and leading into an orifice which com- 
Geol. Rep. Illinois, Vol. II., pp. 219-22). 
