196 



DE. ^n:LLS aVD MB. SMITH OX THE LOWER Pvol. Ixxviii, 



of Cricor Farm, and we can find no evidence of the junction being 

 faulted : — 



Clifnaatgraptus rectangularis 



M'Coy. 

 Difiographts (CHyptograptusJ ta- 



trmriscus 'Nicholson. 



Monograptus acinaces (?) Tofrnquisfc. 

 Mojfwgraptus atavus (fj Jonee. 

 Moiwgraptus cyphus Lapworth. 



Upper Yalentian. — Ii: the Upper, or Tarannon, Series, no 

 fossils indicative of the turriculatus zone have come to light, but 

 the rocks that may be referable to it are very unfossiliferous. 

 The exposure yielding the above-mentioned ^L.-eyphus Zone fossils 

 is separated from an outcrop of the Jf.-cn'spus Beds by the north- 

 and-south Tan-y-graig Fault. Xear the little reservoir here seven 

 fossiliferous loeaKties were discovered in a thickness of some 

 300 feet, in dark striped bands intercalated in the usual grey-green 

 m^udstone. The upper part may represent a portion of the z^jne of 

 J/! griestonensis, but the following forms occurring near the 

 reservoir indicate the 2£.-crispus Zone : — 



Monograptus erispus Lapworth. 

 M. discus Tomqnist. 

 Jf. griestonensis Xieol. 

 M. marri Feiner. 

 Jf. nodifer Tomqnist. 



Monograptus pandus Lapworih. 

 jr. priodon Broun. 

 Jf. runcinatus I^pvoitlL. 

 Jf. spiralis Gfinitz. 



The presence of the griestonensis beds, followed by the darker 

 and often striped crenulatus passage-beds up into the Wenlock 

 Series, has been established at several places in this area. Xear 

 Xant-uchaf , three-quarters of a mile south of Cricor Farm, we find 

 2£onograptus cf. griestonensis Xicol. HL. marri Pemer, and JI. 

 spiralis Greinitz, 210 yards to the north-east : also Jl. priodon 

 Bronn, JT. romerinus var. basil i ens Lap worth, and var. crenulatus 

 Tomquist, about 110 to 130 yards south of that farm. 



In the ravine half a mile north-north-east of Khos-lydan the 

 following forms, in Miss G. L. Elles's opinion, probably indicate 

 the zone of Monograptus griestonensis : — 



Monograptus erispus Lapworth. 

 M. discus Tomqnist, 

 Jf. griestonensis XicoL 

 Jf. marri Pemer. 



Monograptus nudus Lapworth. 

 Jf. pandus Lapworth. 

 M. priodon Bromu 



are 



In Xant-y-garth the passage-beds {~i[.-crenulatus Z;:. 

 admirably exposed about a third of a mile west-north-west f tie 

 6th milestone from Ruthin, and yielded Monograptus ; . ; .= 

 Bronn, J/, romerinus XicholsoUj var. crenulatus Tomqmst, and 

 Metiolites (Qladiograptus) geinitzianus Barrande, var. angusti- 

 dens EUes & Wood. 



