Vol. 62.] ROCKS OF WESTERN CAERMARTHENSRIRE. 615 



harder arenaceous beds. The softer material contains Didymograptus 

 bifidus, Hall, and D. Nicliolsoni, var. planus, Elles & Wood. D. bifidus, 

 Hall, as well as Dinobolus Hichsii, Dav., occurs in the shales on 

 the roadside west of Asgood. 



The old quarry near Danrallt has also yielded a fair number of 

 fossils, including Didymograptus bifidus, Hall ; D. indentus, Hall ; 

 D. Nicliolsoni, Lapw. ; Diplograptus dentatus, Brongn. ; Climaco- 

 graptus confertus, Lapw. ; Illcenus Hughesii, Hicks ; and Barrandea 

 Homfrayi, Hicks. The beds here are nearly vertical, and contain 

 some hard bands. 



West of St. Clears the beds are much exposed in road-sections 

 and otherwise. The road-section at Llaindelyn, south of Pwlltrap, 

 is on the line of the Timber- Yard disturbance, and the mudstones 

 here have yielded : — 



Didymograptus bifidus, Hall. Dhyllograptus anna, Hall. 



Didymograptus indentus, Hall. JEglina binodosa, Salt. 



D/plof/raptus dentatus, Brongn. Bellerophon (1) midtistriatus, Salt. 



Dhyllograptus typus, Hall. | Orthoceras cf. encrinale, Salt. 



Didymograptus bifidus has been collected at Heol-cerrig, several 

 localities on the Backe, and in the dingle between the Woolston- 

 Ash ridge and Castle Hill. Some ' mining ' (sic) operations have 

 been carried on in this dingle, the blackness of the shales being 

 thought a certain indication of the occurrence of coal. Several 

 pits were sunk here, and the debris has yielded D. bifidus, Hall, in 

 fair numbers. 



A short distance north of C16g-y-fran two other pits have been 

 sunk in similar beds, one of which is within a few yards of 

 the fault which here cuts off the Asaplius-tyr annus Limestone. 

 Reference has already been made to Didymograptus-bifidus Beds 

 in C16g-y-fran farmyard. The beds are fairly fossiliferous ; and 

 D. bifidus, Hall, D. indentus, Hall, jEglina binodosa, Salt., 

 JEglina sp., Barrandea cf. Homfrayi, Hicks, and Bellerophon have 

 been collected here. 



There are two outcrops of Didymograptus-bifidus rocks in the 

 vicinity of Forest, separated by a slice of Upper Bala Beds, and the 

 southern outcrop is again faulted against beds of the same age near 

 the tunnel. Fossils are exceedingly scarce, only a few specimens 

 of Climacograptus having been found, and all of them in one 

 locality. Had it not been for the ashes, of which there are three 

 well-developed bands here, it would be difficult to recognize the 

 beds with any degree of certainty. 



West of Forest, the beds seem to be cut off entirely by a fault 

 which appears to bring Bala Beds against Arenig. It cannot be 

 made out exactly what takes place for some distance west, for the 

 ground is obscured by alluvium. But, in the neighbourhood of 

 Whitland, Didymograptus-bifidus Beds again occupy a considerable 

 space. D. bifidus has been collected from a roadside exposure 

 100 yards north of the Intermediate School. The dips up this 

 Q. J. G. S. No. 248. 2 u 



