198 
vine: polyzoa of the wexlock shales. 
Horizon and Locality: Basement beds of Buildwas beds. Har- 
ley No. 22. 
22 Thamniscus antiquas, Vine. 
= Ibid, Quart. Journ.Geol.Soc, May, 1885,p. Ill, figs. 2-a-b-c-d 
Formation: Imbedded in volcanic ash, probably of the age of the 
Bala rocks. 
Locality: Middleton Hall, Welshpo^^l. 
Several species of Thamniscus are described by James Hall in 
his corals and bryozoons, Albany, 1880, from the Lower Helderberg 
group, but in the absence of plates I cannot identify them by the 
descriptive text. 
Thamniscus variolata,Hall,p. 37, 32nd Annual Kept. Albany, 1880. 
„ nysa and var.. Hall. ,, 
„ fruticella, Hall, p. 38, ,, „ ,, 
cisseis, Hall, ., ,, 
All from the Lower Helderberg group near Clarksville, N.Y. 
Ceripora, Goldfuss. 
Pala3ont. Germ., 1826. 
The genus Ceriopora, as originally founded by Goldfuss, has been 
so broken in upon by authors, that it appears to be impossible 
to accept it as sufficiently satisfactory in the present day. 
The Messrs. Young in their paper on Rhabdomeson (Ann. Mag. 
Nat. Hist., May, 1874, pp. 335-339) gave a fair review of Goldfuss's 
genus, and since then Prof. H. A. Nicholson has said, " Ceriopora it- 
self is an illdefined genus, the limits and range of which are not known, 
forms of very diverse affinities having been included by palaionto- 
logists under the name. It is possible, however, that in the recon- 
struction of this genus, certain of the Palaeozoic Polyzoa may be 
found capable of inclusion in it, as a more than merely provisional 
arrangement." * 
The remarks of Professor Nicholson are just, and that for the 
very simple reason, that though we may have a difficulty in defining 
Ceriopora Goldfuss, there is but little difficulty, ^s•ith ordinary care, in 
recognising or identifying the Dudley species of Ceriopora such 
* Manual of PaljBontology, vol. I., Ibid, p. 432. 
