452 Dr. W/icelton Iliml S^- John T. Sfobbs— 



In mlililion to the fossils given in the above section, No. 9 (shell 

 bed) contains Amphwi-zayhrentis sp., Product itx (jiganteus (Mart.), 

 P. Cora, D'Orb., P. hemisplwrictis, J. 8o\v., and ISpiri/er hisulcatits, 

 Sow. No. lo (paper shales) contains Ptcrinopecttn papyrdcens (Sow.) 

 (in abundance), Goniatites. and plant-reuKiins. No. U> (shales and 

 limestones) contains Posidonomya Pecheri, lironn (common), Ortho- 

 ceraa sp., and Dithi/rocaris sp. 



In tlie san\e wood, not many yards from the last section and 

 resting; innnodiately above it, is an excellent exposure of the thinly 

 bedded black limestones, whose upper and lower surfaces are 

 remarkably planar. When struck by a hammer they produce 

 a sonorous metallic 'ohiidc' Their vertical joints, as they are seen 

 passing through all the platy limestones in contact, have the 

 appearance of the sawn edges of a pile of boards. These black 

 limestones of this horizon we will refer to as 'Teilia Beds,' from the 

 fact of their occurrence at a farm called Teilia, near Gwaen-ys-gor. 

 At the quarry already n\entioned near Nant Hall Hotel the beds dip 

 to the west at 5°, and the following list was obtained : — 



Posi(ionomi/a J}<rh(^ri, Bivnu. (Couuuon.) I>i(hi/nH'tjris sp. 



Gouintites. Plaut- vemaius . 



Onhocans sp. 



The same beds are to be found in a quarry under the road leading 

 from Prestatyn to Gwaen-ys-gor (lat. ^S'" 19' 40" N., long. 

 8° 23' 20" W.), where they are faulted to the east against beds of 

 Carboniferous Limestone (see p. o92). The fault can be traced 

 close to the road, and its downthrow to the east is estimated to be 

 at least 80 feet. In this quarry the following fossils were fairly 

 common : — 



Frotliictns pUeatilis, Sow. (h-thocfras^\>. 



Ft>sidonoiin/ii Sechtri, Bivuu. riauts. 



Lower down the hillside and cropping out midway between the 

 first and second bends in the road fnnn Prestatyn (lat. tM*-^ 19'45"N., 

 long, o"^ 23' 2o " W.), the underlying limestone shales were observed 

 dipping S.S.E. at 15*^ and ooutaiuing the following fauna : — 



Timdoniellii l<cvis (Browu\ or yovmg t'onu Ttn^iiiop^ctrn jujpi/racetis (Sow.*). 



of 2\>sidonoinj/a litr/ifii, lirouu. Oli/phwcittif. (biU-;^^ ivtiouluto t'onu.) 



FosiiioHomya iVoArtS, Biviui. ^Alnmdaut.) r Frol<c<initts compressuif. 



The section at Teilia (lat. 68° 19' 15" N., long. 8° 22' 65" W.) 

 has been frequently described, and the plants collected there form 

 the subject of a paper by Mr. K. Kidston,' P.K.S., who in it says 

 (p. -127): "Little or no assistance is given in deciding this poiiit 

 [i.e. the horizon] by the molluscan remains, as some of them extend 

 from the base to the top of the Carboniferous formation." 'J'he 

 following list of the fauna collected at this locality enables the 

 correlation of this horizon to be made with certainty and exactness, 

 not only with those sections above described, but with others in 

 widely separated areas : — 



' Tn\us. Kov. Soo. Edinburgh, vol. xxw (ISSS% pp. 419-4'2S. 



