ON FOSSIL POLYZOA. 191 
(divided) by a central keel on which are often prominences. Cell-mouth 
small, circular and prominent when preserved.’—G. W. Shrubsole. 
Upper Silurian . Fenestella rigidula, M‘Coy. 
a Fe reteporata, Shrubsole. 
‘g 3 lineata » 
5 i intermedia! (a passage form). 
Carboniferous . 53 plebeta, M‘Coy. (Synonyms below.?) 
bs és OF ABSY"-. j55 
a 5 polyporata, Phill. 
3 Fy nodulosa, 
tuberculocarinata, Eth. jun. 
membranacea, ,, 
i - Halkinensis, Shrubsole.* 
Permian . : + retiformis, Schlotheim. 
Prinopora, M‘Coy. 
(See ‘ Brit. Assoc. Rep.’ Foss. Polyzoa, No. 1, 1880.) 
We know but little of this genus, except that the zoarial characters 
are different from those of Fenestella. There is a feather-like arrange- 
ment in the zoarium, a central stem giving off lateral branches, which 
are connected by dissepiments having oval fenestrules. The branches, 
however, rarely bifurcate. 
Carb. Limestone . Ptilopora pluma, M‘Coy (type). 
- Phillipsti, Vine. Castleton, Derbysh. 
PINNATOPORA, 0. gen. 
Zoarium pinnated; with secondary branches, likewise pinnated ; but 
rarely fenestrated by inosculation of pinne. Zoecia tubular, arranged 
biserially, originating immediately beneath, or in a line with, the keel. 
Carina feebly developed in some, well developed in other species, orna- 
mented with the bases of spines, or plain ; no secondary pores. Owcia (?) 
an inflated cell. (For figure see p. 192.) 
Carboniferous . Pinnatopora bipinnata, Phillips = Glauconome of authors. 
gracilis, M‘Coy. 
P i grandis —,, 
gy § pulcherrima ,, 
+3 elegans, Young and Young. 
= Glauconome, Y. and Y. 
sf aspera, Young and Young. 
3 flewicarinata a 
3 retroflexa 3 
ee robusta . 
ee laxa 
P= G: elegantula, Eth. jun. 
1 This name had been previously adopted by Mr. Prout for an American Car- 
boniferous species of Fenestella, closely related to F. Milleri, Lonsd. 
* For synonyms see G. W. Shrubsole on ‘ Carb. Fenestellidz ’ (op. cit.) 
* There are still some few Carboniferous Fenestelle left which may ultimately 
merit specific distinction. At present I cannot include in this list more species than 
those already given. 
