194 Dr. H. Woodward—On some remarkable Cystideans. 
Pectinated rhombs apparently none. Arms unknown. Column 
deeply inserted into the body, composed of large joints above, 
becoming smaller below.” 
In the Bulletin del’Académie Royal, Bruxelles, 1869 (2nde série, 
tome xxviii. pp. 57-65, Planche), Prof. L. G. de Koninck, of Liége, 
gives descriptions of “some new and remarkable Echinoderms 
from the British Paleozoic Rocks.” This paper, a translation of 
which I published, together with the original plate, in London (see 
GroLtocicaL Magazine, 1870, Vol. VII. pp. 258-263, Pl. VIL), 
gives, among others, a fairly accurate description (as far as could be 
made out from the specimen) of a new Cystidean from the Upper 
Silurian of Dudley, under the name of Placocystites Forbesii.' 
I appended a note to this paper (on p. 261, Grou. Mac. 1870), | 
adding further details concerning this fossil, and I also then expressed 
my conviction that Placocystites Forbesii, De Kon., and Ateleocystites 
. Huxley, Billmgs, would probably hereafter be shown to be the 
*“‘anterior ” and “ posterior ” surfaces of the same Cystidean.” 
Having obtained a large series of Placocystites Forbesii, De Kon., 
from Dudley, I was enabled to make an accurate drawing of both 
the “dorsal” and “ventral” aspect of this anomalous fossil, which 
I forwarded, in 1870, by Sir W. E. Logan, to Mr. E. Billings in 
Montreal. His reply, together with my figures and remarks thereon, 
appeared in the Gronocioan Magazine for 1871 (Vol. VIII. pp. 
71-72 and woodcut), which are reprinted herewith. 
I subjoin a copy of the woodcut, and have drawn up a brief 
description of Ateleocystites (Placocystites) Forbesii, De Koninck, as 
it has never been heretofore fully described. 
Order—CYSTOIDEHA. 
Family.—ANomaALocystID&. 
Genus.— Aieleocystites, Billings, 1858. 
Syn. Anomalocystites, Hall, 1859. 
Placocystites, De Koninck, 1869. 
? Ateleocystites, Meek, 18738. 
Enoploura, Wetherby, 1879. 
Grnus.—Body compressed in form, posterior side convex, anterior 
side concave, composed of about four series of plates, more numerous 
and more symmetrically disposed on the convex side, less numerous 
and somewhat less symmetrically disposed on the concave side. 
All the body-plates (with the exception of the ovarian plate) 
having a finely striated and wavy ornamentation, running in an 
obliquely-transverse direction across their surface. 
The “anal” plate is placed on the central line on the convex side® 
of the body at the junction of two plates placed in juxtaposition and 
immediately above the “ovarian” plate. Arms two or more in 
number, pinnulz small or absent? Base excavated for the insertion 
* Only the convex side was examined and described by Profs de Koninck; the 
concave side yielded no information to its learned investigator, being imperfect. 
* In this it appears I was in error. Mr. Billings did not affirm them to be 
actually the same species, but only to belong to the same genus; I misread his note 
to me at'the time. M. de Koninck’s syecies should therefore be retained. 
5 Referred to by Billings as the ‘‘ ventral” side. 
