Vol. 62.] ROCKS OF WESTERN CAERMARTHENSHIRE. 609 



The roadside-exposure at the entrance to Llangan Vicarage is 

 presumably the ' north of Talvan ' locality of the late Thomas 

 lloberts. These beds succeed the gritty mudstones mentioned above, 

 apparently without a break, and this agrees with the succession 

 elsewhere. The fossils collected here include the following, most 

 of which were recorded by Mr. Roberts : — 



Dictyograpius sp. Callog rapt us persculptus, Hall. 



Dendrograptus sp. DicJiograptus sp. 



Didymograptus nitidus, Hall. jEglina sp. 



Didymograptus pafulus, Hall. 

 Tetragraptus Headi, Hall. 

 Tetragraptus serra, Brongn. 

 Callograpius Salteri, Hall. 



Trinucleus Sedgwielii, Salt. 

 Orthis calligramma (!) Dalm. 



Pakearca. 

 Obolella. 



The old lane at Pontygraig, east of Trcfach, cuts through the 

 same beds, which contain a fair number of fossils. Among others, 

 the following occur : — Didymograptus extensus, Hall ; D. patulus, 

 Hall ; Tetragraptus Amii, Lapw. ; Dendrograptus sp. ; JEglina, 

 and other trilobite-fragments. 



The old road-section at Penparc-uchaf is in shales of the same 

 age, and fossils are fairly abundant, especially graptolites. The 

 following were collected : — 



Didymograptus extensus, Hall. 

 Didymograptus sparsus, Hopk. 



Didymograptus patidus, Hall. 

 Didymograptus nitidus, Hall. 

 Tetragraptus Headi, Hall. 

 Tetragraptus Bigsbyi, Hall. 



Dendrograptus sp. 

 Dictyograpius sp. 

 Dichograptus sp. 



Several species of small trilobites 

 and an Orthis. 



Extensiform graptolites have been collected at Pwllyrhwyaid and 

 Foxhall, north of "Whitland. 



In the old quarry north-east of Llanlliwe there are some thickly- 

 bedded mudstones, with the beds almost vertical and much crushed. 

 Some bedding-planes are covered with graptolites, but the material 

 crumbles to pieces on being handled, making it difficult to secure a 

 good identifiable specimen. Some large trilobites also occur here, 

 but they are much distorted and broken. Among the graptolites the 

 following have been made out : — Didymograptus extensus, Hall ; 

 D. nitidus, Hall ; Tetragraptus Headi, Hall ; T. Bigsbyi, Hall ; 

 and Dichograptus sp. 



The shales at Sarnlas near Llangan Church, though abundantly 

 exposed, contain few fossils. Those that do occur lead to the 

 conclusion that these beds are at the top of the Tetragraptus-series, 

 or at least very near the top. The fossils include fragments of 

 Didymograptus (l)hirundo, Salt. ; Diplograptus dentatus, Brongn,; 

 Climacograptus confertus, Lapw. ; JSglina sp. ; Obolella plumbcea, 

 Salt. 



There are also numerous exposures of shales at Blaenwernddu. 

 These present the characteristic weathering of the Tetragraptus- 

 Beds, but fossils occur very sparingly. The specimens found are 



