The Carhoniferous Succession below the Coal- Measures. 447 



micropterus, which is probably A. dissimilis (Flem.) ; and (3) Zaphrentis 

 cyUndrica, which is either Campophyllum or Amplexi-zaphrentis. 



The Prodiictus giganteiis beds are succeeded by yellowish sandy 

 limestones and a pebbly grit, and at the top of the hill are the 

 strong cherts of Pen-y-Bwlch. Morton estimates tlie Carboniferous 

 Limestone of the Eglwyseg ridge at 1,200 feet, which he subdivided 

 as under : — 



feet. 



Upper Grey Limestone 300 



Upper White Limestone 300 



Lower White Limestone ... ... 120 



Lower Brown Limestone 480 



1200 



These beds are all exposed either in the fine escarpment of the 

 Eglwyseg ridge or the Trevor and Bronheulog quarries, and rest in 

 places on a basement of red conglomerate, which is to be seen near 

 Dibren Uchaf and at the foot of Craig-yr-ogof. The brown lime- 

 stones at the base of the limestone series contain plant-remains in 

 a fragmentary state. The most abundant and characteristic fossil is 

 Daviesiella Liang oUensis. The number of fossil species is not large, 

 but individuals are fairly numerous, and we collected the following : — 



Alveolites septosa (Flem.). Eetieularia lineata (Mart.). 



Syringopora sp. Belleroplton sp. 



Athyris planosulcata, Phill. A Nautiloicl shell. (Fragmentary.) 



Daviesiella LlangoUcnsis (Dar. sp.). Eimnphalus Dionysii, Goldfuss. 



Producttos Cora, D'Orb. Murchisonia KendalcnsiSjWGoy (DousXiSi). 



Fragments of a giganteid Productus. Pleurotomaria. (Large globular species.) 



A list which is almost identical with that of G. H. Morton. 



The fossils all seem to come from the lower part of the series. 

 They are not very common in the whiter beds above the Brown 

 Limestone, but we obtained the following : — 



Cyathophyllnm Murchisoni, 'E. & H. Chonctes papilionaeea, VhUl. (Flattened 



Dibunophyllum sp. form.) 



Lithostrotion Martini, E. & H. Productus Cora, D'Orb. 



Syringopora sp. P. gigaiiteus (Mart.). 



Athyns expansa, Phill. Edmondia sulcata (Phill.). 



Sanguinolites striatolamcllosus , De Kon. 



Morton states that he found Lonsdaleta duplicata (Mart.) and 

 L. rugosa, M'Coy, Lithostrotion irregidare (Phill.), L. j'unceum 

 (Flem.), and Z. Fortlocki (Bronn) at this horizon. In the appendix 

 to his larger work, "Tlie Geology of the Country round Liverpool," 

 p. 318, he says : "Of the 37 species in the Upper Grey Limestone 

 of Flintshire there is only one which seems peculiar to it, and that 

 is Lonsdaleia rugosa, but it occurs in the Middle White Limestone 

 of Llangollen." We find that the range of this fossil includes 

 a portion of the Middle White Limestone of Morton. 



Mistakes might easily occur at the Eglwyseg ridge unless the 

 specimen were actually taken from the rocks in sitd, for slopes of 

 talus extend largely from the top to the base of the hill, and fossils 

 from the upper beds are brought down in this way and mingle with 

 those from the lower beds. 



