76 REPORT—1857. 
gested. These are the membranous tubes of a tentaculated worm, which inhabited a 
trumpet-shaped burrow, bent up at the lower end: this occurs at Bray abundantly in 
a Cambrian sea-beach. 3rd. Molluscan (?): markings precisely similar to those so 
called in the carboniferous slates. These are from Bray. The worm-tracks of Howth 
do not appear to be identical with those of Bray. All the fossils at this latter place 
would appear to have been deposited in shallow, quiet waters. 
On the Relation between the Cleavage of Minerals and the Cleavage of Rocks. 
By Professor Kine. 
On a Section across Slieve-na-Muck, Co. Tipperary. By J. O. Kevry. 
On the genus Woodocrinus. 
By Prof. L. de Kontnck, F.G.S.; and Epwarp Woon, F.G.S. 
In the year 1854, when the genus Woodocrinus was first described, a single species 
only had been discovered. 
Since then so much attention has been paid to these fossils, that we have succeeded 
in procuring three new species belonging to the same genus, the details of which 
appear to be by no means less interesting than those of the species which formed the 
type of the genus; and they offer some peculiarities which tend to modify and com- 
plete the characters which have been assigned to it. 
We therefore think that a reproduction of the published definition of this genus, 
together with the modifications which the discovery of the new species has forced 
upon our notice, will not be a work altogether unworthy of a short memoir. 
Genus Woopocrinus, Kon. 1854. 
Generic characters.—Basal plates 5. Subradial plates 5, alternating with the 
basal plates. Radial plates 2X5=10, united laterally. Interradial plates none. 
Anal plates 8 to 20. _ Brachial pieces 4 to 10. Number of arms 10, bifurcating 1 
to 5 times and furnished with pinnules. Joints of the stem cylindrical, tapering 
towards the outer extremity. Dome composed of a great number of small hexagonal 
plates, marked with star-like rays. 
The calyx* of this genus takes the form of a widely-opened cup, the base of which 
is composed of five equal quadrangular plates, forming by their union a star with 
five rays. Alternating with and above these basal plates, is a row of five hexagonal 
plates, which in their turn alternate with the first radial pieces, to the base of which 
they are united by one of their sides. The radial pieces are two to each ray; these 
two pieces, the second of which is axillary, are cuneiform and of the same size and 
shape; with the exception of those which are adjacent to the anal region, all these 
pieces are jointed by their lateral edges, and show no trace of interradial pieces. 
To each ray there is a single bifurcation, consequently ten arms. The number of 
brachial pieces is variable; but of the species at present known, no specimen has less 
than four or more than ten. The arms bifurcate from one to four and sometimes five 
times, according to thespecies. The parts not laterally united are composed of alter~ 
nate articulations, on the interior sides of which are inserted the pinnules, each of 
ten to twelve small pieces superposed one upon the other, and with a length greater 
than their breadth. The anal region is composed of a great number of plates (8 to 
20), varying in each species. The dome appears to have been formed of small pen- 
tagonal or hexagonal regular plates, The stem, of a variable length, is composed of 
cylindrical articulations, alternately larger and smaller: its special character is, that, 
unlike the stem of all other known Crinoids, it is much thinner at the base than at 
the summit; this circumstance would lead us to conjecture that the Woodocrinus 
ees freely in the water, and that the stems were used to keep it upright while it 
floated}. 
* The nomenclature is that determined by MM. de Koninck and Le Hon, in their 
Monograph of the Belgian Carboniferous Crinoids. 
t+ This peculiarity seems also to point out that the genus Woodocrinus may form a link 
between the fixed Crinoids and the adult state of the genus Comatula. Another conjecture 
might be hazarded, viz, that these Crinoids were fixed on the rocks near tide-mark, and that 
ot ies 
