TRANSACTIONS OF THE SECTIONS. 77 
Relations and differences.—This genus, which has been named after the zealous 
amateur who alone has brought the specimens to light, is related to the genera 
Cyathocrinus (Miller), Taxocrinus (Phill.), and Forbestocrinus (Kon.). The charac- 
ters which mark their differences are easy to distinguish. 
The Cyathocrinus has normally only four subradial plates, while the Woodocrinus 
has five, andthe Zaxocrinus, as well as the Forbesiocrinus, have none. Besides, the 
principal rays of the two last genera are composed of more than two radial plates. 
The known species of this genus are Woodocrinus macrodactylus, Woodocrinus 
expansus, Woodocrinus goniodactylus, and Woodocrinus dichodactylus. 
1. Woopocrinus Macropactytus.—As this species has been fully described in a 
notice on a new genus of Crinoids, read by M. de Koninck, February 1854, before the 
Academy of Belgium, it will not be necessary to enter into its details. We would 
here only add, that it is by far the mest common; the thin limestone bed of a very 
limited area, in which this genus has alone been found, having as yet furnished but 
very few specimens of the other three species, while its flags are covered with the stems, 
arms, and calyces of the W. macrodactylus, twisted over each other, knotted, inter- 
laced in almost inextricable confusion, and in such numbers as show that the ocean 
where they lived was not less full of life, because its denizens were so special, than 
those seas which have furnished to the naturalist genera much more numerous. 
It may be further added, that the above beds have furnished as yet no other fossil 
except the Woodocrinus and a few teeth of Petalodus Hastingsia and acuminatus 
(Agass.). 
2. Woopocrinus Expansus.—The calyx of this species is composed of plates which 
bear a close resemblance to those of Woodocrinus macrodactylus; their position is 
exactly the same, and by their union they form a vase-like cup; but the diameter of 
these plates is greater, and they appear to be thicker and stronger than those of W. 
macrodactylus. 
The basal plates are small, and the height of the exterior part is not equal to its 
breadth. The articulated surface of the base is very broad, and forms with the 
exterior surface, an angle almost equal to a right angle. The subradial plates are 
equal in length and breadth. The length of the first radial pieces is not equal to 
their breadth. Their thickness appears to be considerable. The second radial pieces 
are axillary and very short, though as broad as the first; from each springs two 
arms, one of which is generally composed of three to four and the other of four or 
five brachial pieces, which generally have a length three times that of their breadth. 
Each arm gives origin to two primary brachial rays, composed of nine and five 
brachial joints. The first is divided into two secondary rays, one bifurcating again 
once or twice before it attains its greatest length. ‘The other, composed of about fifty 
brachial joints, remains single. The second divides also into two secondary rays, one 
bifurcating, the other single. The joints of these rays are almost semi-cylindrical, 
with their breadth and length nearly equal, and alternately a little thicker on each 
opposite side. The pinnules to which they give origin are exactly similar to those of 
Woodocrinus macrodactylus. The number of the ultimate rays of this crinoid is 80 to 
100, and the total length of the arms is three times that of the calyx. The anal 
region, the form of which can be but imperfectly distinguished, and that only in a 
single specimen, appears to be composed of fewer plates than that of Woodocrinus 
macrodactylus; but these plates are broader and thicker than those of the above species, 
though their general disposition is the same. The dome imperfectly marked, and 
that in but two specimens, appears to have been large, and composed of a great num- 
ber of hexagonal united to pentagonal plates, having their surface ornamented with 
stars in relief, not unlike the dog-toothed ornament of early English architecture. 
The proboscis of this species has not yet been found. The stem, in its general form, 
and the form of its articulations, resembles that of the W. macrodactylus, but it is 
usually larger and a little thicker. 
Relations and differences.— Woodocrinus expansus differs from W. macrodactylus 
their flexible stems permitted their arms to rise and fall with the tide, and that when dead they 
broke off, and the floating bodies were cast on the beach; which would account for the con- 
fusion with which they seem thrown together, and for the absence of any fixed base to the 
stems, 
