The Carboniferous Succession beloic the Coal-Measures. 395 



In the bed forming tlie floor of the quarry the following fossils were 



obtained : — 



Bibunophyllum sp. P. hemisphericus , J. vSow. 



Crinoids. Reticularia lineata (Mart.). 



Productus giganteus (Mart.), ? Spirifer rotundatus, Sow. 



(xvi) On the eastern flank of Halkyn Mountain the upper beds 

 have been worked in a series of quarries from Trelogan to Pentre 

 Halkyn for ' Aberdo ' limestone. The individual beds are never 

 tliick — 2 feet or 2 ft. 6 in. being the maximum — and usually they 

 are separated by thin shale-bands. As we go north the shale- 

 partings constitute an increasing pi-oportion of the sections, as may 

 be seen by comparing the photographs, Plates XXI and XXII and 

 Fig. 1. One of the quarries opened up in these beds was examined 

 at Gorsedd (lat. 53° 16' 50" N., long. 3° 16' 10" W.), where the shales 

 and limestones were all highly fossiliferous. Undoubtedly the most 

 striking form, by reason of its numbers and the development of its 

 individuals, was Productus giganteus (Mart.). The full list from this 

 quarry was : — 



Athyris cl. planosulcata, Phill. P. semireticiilatus (Mart.). 



Chonetes sp. P. Youngianus, Dav. 



Lingula mytiloides^ Sow. Reticularia lineata (Mart.). 



Orbiculoidea nitida (Phill.). Rhipidomella Michelini (L'Eveille). 



Orthofetes crenistria (Phill.). Schizophoria resupinata (Mart.). 



Pi-odiictus giganteus (Mart.). (Very Spirifer sp. 



common.) Phillipsia sp. 



(xvii) About one and a half miles further south, on the road to 

 Holywell, a very large quarry has worked beds at the same horizon 

 and of the same quality (i.e. 'Aberdo' stone) at the Grange, Hollo- 

 way (lat. 53° 16' 30" N., long. 3° 14' 25" W.). At this quarry we 

 get an uninterrupted sequence from the limestone, through the cherts, 

 into the lowest shales and thin black limestones of the Pendleside 

 Series. Overlying the ' Aberdo ' beds there is a white lime- 

 stone, almost 7 feet thick, the lower portion of which is cherty and 

 the upper portion is crinoidal ; resting upon the latter is about 6 feet 

 of lenticular dark limestone and thin shales, and these pass upwards 

 into the cherts, which at this locality are thinly bedded, and as a 

 series are attenuated. The cherts dip eastwards at 22° (PI. XXI) 

 In the limestones and intervening shales we collected — 



Lithostrotion irregiilare. P. scalriculus (Mart.). 



Amplexi-zaphrentis 6, Vaughan MS. P. semireticulatus (Mart.). 



Caniniad — Bibunophyllum, Vaughan MS. Reticularia lineata (Mart.). 



Dibunophyllum sp. Rhipidomella Michelini (L'Eveille). 



Favosites parasitica (Phill.). Spirifer, var. of S. bisulcatus, Sow. 



Fenestella. S. ovalis, Phill. 



Athyris planosulcata, Phill. S. planicostatus, M'Coy (not S. crassus, 



Chonetes Buchiana, De Kon. De Kon.). 



C. Laguessiana, De Kon. , Spiriferina sp. 



C. pnpilionacea, Phill. Syringothyris cuspidafa (Mart.). 



Orthotetes crenistria (Phill.). Aviculopecfen dissitnilis (Flem.). 



Productus eorrugatus,^ Phill. Orthoceras sp. 



P. giganteus (Mart.). (Common.) Phillipsia sp. 



P. longispinus, Sow. Petalodus acuminatus (Agass.). 



^ This form is characteristic of the Upper BibuJiophyUiim zone. 



