ON THE BRITISH CARBONIFEROUS FENESTELLID A. 975 
22. A Revisw of the British CARBONIFEROUS FunnstEtirp 2, 
By Groner Wm. Surussore, Hsq., F.G.S. (Read February 26, 1879.) 
Tue following are some of the results obtained in working out the 
fossil Polyzoa found in the upper beds of the Carboniferous Lime- 
stone on Halkin Mountain in Flintshire. 
In some of the bands of calcareous black shale and chert the 
Fenestellidee occur in considerable abundance, and generally in a 
good state of preservation. During the last few years some thou- 
sands of specimens, mainly of Menestella, from this locality have 
come under my notice. The condition of many of these has been 
such as, 1 conceive, to throw considerable light upon their true 
form and mode of growth, and so to add largely to the information 
we possess respecting this interesting group of the Polyzoa, and 
render possible what has been long felt to be a desideratum by all 
who have studied the subject, namely, a revision of the several 
species of Fenestella. 
Twenty-six so-called species of Fenestella have been described 
from the Carboniferous series. Of these I have carefully examined 
twenty, and find that they can be reduced to five species. 
The following is a complete list of the British Carboniferous 
Fenestelle :— 
Fenestella antiqua, Lonsd., M‘Coy, Syn. Carb. Foss. Ireland, p. 200. 
arctica, var. scotica, Eth. jun., Ann. & Mag. Nat. Hist. ser. 4, vol. xx. 
Jol. 
Peter ecititnta, Eth. jun., Mem. Geol. Sury. Scotland, sheet 23, p. 101. 
— carinata, M‘Coy, Syn. Carb. Koss. Ireland, pl. 28. fig. 12. 
—— crassa, M‘Coy, Syn. Carb. Foss. Ireland, pl. 29. fig. 1. 
— ejuncida, M@*Coy, Syn. Carb. Foss. Ireland, pl. 28. fig. 11. 
flabellata, Phil/., Geology of Yorkshire, pl. 1. figs. 7-10. 
flustriformis, Phill., Geology of Yorkshire, pl. 1. figs. 11, 12, 
frutex, M‘Coy, Syn. Carb. Foss. Ireland, pl. 28. fig. 10. 
formosa, M‘Coy, Syn. Carb. Foss. Ireland, pl. 29. fig. 2. 
hemispherica, M*Coy, Syn. Carb. Foss. Ireland, pl. 29. 
irregularis, Phill., Geology of Yorkshire, pl. 1. figs. 21, 22. 
laxa, Phill., Geology of Yorkshire, pl. 1. figs. 26-30. 
—— membranacea, Phill., Geology of Yorkshire, pl. 1. figs. 1-6. 
— Morrisii, M‘Coy, Syn. Carb. Foss. Ireland, pl. 28. fig. 14. 
— multiporata, M‘Coy, Syn. Carb. Foss. Ireland, pl. 28. fig. 9. 
— nodulosa, Phill., Geology of Yorkshire, pl. 1. figs. 31, 32, 33. 
— oculata, M‘Coy, Syn. Carb. Foss. Ireland, pl. 28. fig. 15. 
-—— plebeia, M‘Coy, Syn. Carb. Foss. Ireland, pl. 29. fig. 3. 
— polyporata, Phill., Geology of Yorkshire, pl. 1. figs. 19, 20. 
— quadradecimalis, M‘Coy, Syn. Carb. Foss. Ireland, pl. 28. fig. 13. 
— tenuifila, Phill., Geology of Yorkshire, pl. 1. figs. 23, 24, 25. 
— tuberculo-carinata, Eth. jun., Mem. Geol, Sury. Scotland, sheet 28, p. 101. 
— undulata, Phill., Geology of Yorkshire, pl. 1. figs. 16, 17, 18. 
yaricosa, M‘Coy, Syn. Carb. Foss. Ireland, pl. 28. fig. 8. 
The causes which haye contributed the most to the present con- 
fusion in the group haye been :—(1) a very imperfect acquaintance 
