64 



VINE : POLYZOA OF REDESDALE. 



tion to the peculiarity of the structure in Palaeozoic Bryozoa. The 

 present species has a denticulated orifice, and I have noticed that the 

 closure of some of the cells appears to be nothing more than a thin 

 pelHcle of calcareous matter — so transparent that the denticulated 

 orifice can be seen beneath. I cannot as yet comprehend the value 

 of this closure in the economy of the species, but it is well to note 

 the fact whenever it is observed. The 'closure' is a common 

 feature in both the Fenestella and Polypora of the Carboniferous 

 rocks, but I have not noted it before in this group. 



5 Acanthopora stellipora var. spinosa Young and Young. 

 This variety is also present in the shales, but so worn that it is 



with difficulty that the characters can be made out. It is only on 

 account of the peculiar spinose keel — which is fairly preserved in 

 one or two fragments — that I direct attention to it at all. 



6 Diplopora marginalis Young and Young. 



= Glauconome {Diplopora) marginalis Young and Young, 

 Proceed. Nat. Hist. Soc. Glasgow, March 1875, pi. iii., 

 figs. 14-21. 



In the Scotch Hairmyres Shales this species is a very delicate 

 one — in the Gair Shales it is rather more robust — but in the Redesdale 

 Shales it is both delicate and robust. It is rather rare, and unless a 

 little care is exercised the fragments may be passed over —especially 

 the more minute of these. 



7 Actinostoma fenestratum Young and Young, Quart. Journal. 



Geol. Soc, Dec. 1874, p. 682, pi. xl., figs. 1-4; pi. xli., 

 figs. 12-16. 



This is another of the beautifully stellate species abundant in the 

 Scotch beds — rather rare in the English. Fragments of the species 

 may easily be mistaken for Acanthopora stellipora^ only if a little 

 patience is exercised in the observation it will be found that there are 

 no lateral pinnae — but instead, delicate portions of the dissepiments 

 wholly destitute of pores. 



8 Hyphasmopora Buskii R. Etheridge, jun. 



Ann. Mag. Nat. Hist. Ser. IV,, vol. xv., pp. 42-45, pi. iv., fig. 1-4. 



Carb. Polyzoa North Yorkshire, Vine (op. cit.) p. 337, pi. xvi., fig. 6. 

 This very characteristic polyzoon is perhaps one of the most 

 beautiful from the Scotch Shales. In the Shales of North Yorkshire — in 

 the Redesdale Shales, and also in others of the Northumbrian Shales 

 this species is present, but it is rare. In another paper sent on to the 

 Yorkshire Geol. Soc. — but not yet published — I have drawn attention 

 to a new ally of this species ; so far as I am aware, new to the British 

 Carboniferous rocks. I have named it Strehlotrypa Nicklesi Ulrich 

 (MS.), from the fact that the American specimen sent to me by Mr. 



Naturalist, 



