KONINCK — NEW PALiEOZOIC CRINOTDS. 
183 
it is probable that the disposition of the other plates of the calix is the 
same in that genus as in that which I here propose. 
Position and Distribution. — I know, as yet, but two species of the 
genus Pisocrinus, both from the Upper Silurian limestone of the 
neighbourhood of Dudley, where they have been discovered by Mr. 
John Gray, of Hagley, whose patient researches have enriched the 
English Silurian fauna with a great number of remarkable animals. 
1. Pisocrinus Pilula. De Koninclc. PL lY., fig. 8 — 11. 
The Calix of this species is of the size of a large pea, of which it puts on at the 
same time the form, saving the truncation, produced by the opening above. The 
surface is entirely smooth, and also slightly glistening. The base is perfectly of 
the form of an equilateral and slightly broad triangle. 'J'he articulation of the 
stem is placed at the bottom of a rather deep and wide hollow. The sub-radial 
plate, somewhat broader than long, is bounded in its upper part by an obtuse 
angle, which arrests it at w. short distance from the upper edge of the calix. It 
results from this that the two radial plates, resting upon this plate, are not quite 
triangular in form (Fig. 8). 
The five radial plates have their upper surface deeply furrowed for the reception 
of the second plate, which should surmount them, but which remains unknown 
to me. The opening of the calix is almost circular, or rather sub-decagonal through 
the little slopes existing on the various pieces ; that which corresponds to the 
anal side is a little more decided, as is displayed in figure 11. 
Affinities and Differences. — This species distinguishes itself from the 
following by the absence of all ornament on its surface, and by its 
much more globular form. 
Dimensions. — Length about 5°"° ; diameter of same dimension ; 
diameter of the articulation of the stem 1°"°. 
Position and Locality . — I know as yet but two specimens of this species; 
one in the rich collection of Mr. Gray, the other in my own. I owe 
the last to the kindness of Mr. Lewis of London, whom I have seen 
with regret abandon the study of palaeontology, to the advancement of 
which he has contributed powerfully by his active researches. 
Explanation of figures. — PI. IV: — 
Fig. 8. — Specimen, magnified, view of the anal side. In the collection of Mr. 
Gray, of Hagley. 
Fig. 8 a. — The same, of natural size, view of the same side. 
Akad. der Wiss., 1850, No. G, p. 248), for some palfcozoic crinoids from the Eifel, 
is identical with the genus Triacrinus. This is only possible for me to decide by 
an inspection of the specimens described by von Miinster, of which the figure in 
outline (Beitrage z. Petrefakt., I, pi. I, fig. 4, c) is evidently defective ; for, if it 
were actually the expression of the reality, it would follow that there existed 
crinoids with three rays instead of five, which is not probable. 
