CALYPTOCRINIDZ. 335 
Remarks. — Hucalyptocrinus was originally described by Goldfuss as hav- 
ing no stem; and Phillips, who discovered another species with the stem 
attached, proposed for this the genus Hypanthocrinus. Angelin and Zittel, 
who accepted Phillips’ genus, describe its base as less deeply funnel-shaped, 
the anal tube as extending beyond the tips of the arms, and the partition 
walls enclosing the arms as being constructed principally of one piece. 
Neither one of these characters is constant, and we cannot regard the two 
forms as distinct generically. That the anal tube rises above the arms is of 
very little structural value, if we admit that the neck-like prolongation 
from the disk represents a part of that tube. The earlier writers describe 
the radials as basals. Roemer discovered the true base in 1843, but he 
supposed it was quinque-partite, and so did de Koninck and Le Hon, Hall in 
1863 found that it consisted of but four plates, and this was confirmed by 
subsequent authors. 
Eucalyptocrinus is a most perplexing genus, owing to the peculiar struc- 
ture of its ventral part, which was apparently not correctly understood by 
Hall. He described the partition walls as interbrachials ; while in fact they are 
not separate plates, but the outer processes from the plates of the disk and 
tube, respectively, a sort of compound structure for which we adopt the name 
“partition walls.” The twenty plates forming the lower ring of the disk we 
regard as large interambulacral plates meeting over the ambulacra; but as 
to the relations of the plates of the second ring we are somewhat in doubt. 
We have suggested in Revision, Part IIL, p. 132, that they probably repre- 
sented four of the orals, and that the fifth was pushed upward, and consti- 
tutes a part of the anal tube. This seems not improbable if we consider that 
the posterior oral in all Paleozoic Crinoids is pushed more or less out of 
place by the anus; and it may be expected that this was the case to a high 
degree in a genus in which the anal tube is large and strictly central. 
Miller's Hucalyptocrinus ellipticus is too young a specimen to determine its 
specific relations. A similar specimen from Rochester, N. Y., is figured by us 
on Plate LXXXIIL., Fig. 7. 
Eucalyptocrinus tennessee, FE. Phillipsi, E. conicus, E. nashville, E. extensus, 
E. gibbosus, E. levis, and E. Goldfussi, all of Troost, are mere catalogue names. 
EF. armosus McChesney is a Siphonocrinus, and EF. cornutus, EF. excavatus, 
both described by Hall, and 2. ramifer of Roemer, have been referred by us 
to Callicrinus. 
