VINE : NOTES ON YOKEDALE POLYZOA. 
89 
Localities: Yoredale ; ITolker Park, common; Hurst, Yorkshire. 
21. PoLYPOKA (?) sp., provisional. 
There are present in the North Lancashire rocks fragments of 
what may ultimately prove to be another species of Polypora, but my 
example does not warrant their individualisation. In the Derbyshire 
and North Yorkshire strata 1 regard the Polypora laxa, Phillips', as 
distinct from either of the above. 
Phylloi^ora is not, so far as I am acquainted with Pali^ozoic 
Polyzoa, a Carboniferous Genus. Species of the Genus are found 
in the Silurian Rocks, both of this country and America ; there are 
examples of the Genus in the Permian Rocks also. 
Family TllAMNISClDA. 
1883. Fourth Brit. Assoc. Report, Fossil Pol^^zoa. 
Zoarlum forming- free dichotomising- branches, or pinnated 
fronds. Zocecia on one side only, with from three to five (or more ?) 
rows of cell openings in the branch, occasionally having a smaller 
opening above or below the peristome of the cell (base of a spine ?). 
Genus Thamnlscus, King. 
Genus Acanthocladia, King ? = Ichthyorachis, M'Coy. 
In my paper on West Yorkshire and Derbyshire Polyzoa 
(Proc. Yorks, Geol. Soc, 1883), I describe a new variety of 
ThamnisGus duhuis ? King, Avhich I characterise as var Carbonarius 
(pp. cit. p. 170), and Messrs. Young, of Glasgow, have also described 
a Scotch form which they named T. Rankinei, which is doubtfully 
present in the North Lancashire material. 
Genus Thamniscus, King (Permian Fossils). 
Restricted by Mr. G. W. Shrubsole, Quart. Jour. Geol. Soc, Aug., 
1882. 
Zoarium mulitiform ; branches free, round, frequently and 
regularly bifurcating, more or less in one plane. Zoacia on one side, 
cells immersed, apertures round, arranged in oblique lines. Reverse 
foraminated. 
22. Thamniscus DUBIUS, King (Permian Fossils) Var. a. carbonarius, 
Vine, Proc. York. Geol. Soc, 1883, p. 171. 
I place some fragments from Holker Park here, but I am rather 
doubtful of the association. 
