Vol. 55.] LOWEK PALEOZOIC EOCKS OF COUNTY WATERFOED. 723 



dip at 45° north-westward. It is from these beds that the organic 

 remains were obtained which were described by Portlock and 

 others ^ from the locality called Newtown Head. 



Salter ^ describes the following trilobites from these beds : — 



Acidaspis Jamesii, Salt. Trinucleus seticornis, His. ( = kiberni- 

 Ampkion benevolens, Salt. cus, Reed). 



Aiwpyx mammillat'us, Sars. Salieria involuta, Salt. 

 Barrandia Portlockii, Salt. 



Davidson -^ mentions the following brachiopods : — 



1/lngula ovata, M'Coy. j Crania divaricata, M'Coy. 

 brevis, Port] . j Strophomena corrugatella, Dav. 



In the Dublin Museum of Science & Art are the Geological 

 Survey collections, and I have had the privilege of examining them, 

 with the result of identifying the following species from Newtown 

 Head. Those marked with an asterisk have been collected also by 

 me from these beds. 



Orthis calligramma, Dalra. 

 FlectamhoniteHqmnquecostata,'M.'Goj. 

 Lingula brevis, Portl. 

 Orbictdoidea oblongata, Portl. 

 Fholidops / balcletchienais,, Dav. 

 Ctenodonta sp. 



Bellerophon perturbatus, Sow. 

 Pleurotomaria sp. ? 

 Orthoceras gracile, Portl. 



sp. 



Hyolithes of. striatus, Eichw. 

 EchinosphcBra granitiata, M'Ooy ? 

 ^ Glyptocystis of. pennigera, Eichw. 

 Dicellographts sp. 

 Bidymograptus sp. 



The commonest fossils occurring here are Amjpyx mammillatus, 

 Orthis argentea, and Trinucleus hibernicus. The beds do not seem 

 divisible into zones, the same general facies occurring throughout, 

 but the exposure has been too limited on the occasions of my visits 

 to collect with the idea of zonal subdivision. 



A wedge of very decomposed felsite, some 4 to 5 feet wide, is 

 exposed close under the clitfs, running into these fossiliferous beds 

 near their base. At the base of the mudstones are found thin- 

 bedded cherts [601] [500] 12 feet thick, and below them come grey 

 felsites and ashes in alternating layers, amounting in all to about 

 30 feet, with the usual strike and dip. Underlying them is a 

 coarse volcanic agglomerate composed of large rounded or subangular 

 lumps and small angular fragments of various felsites, slates, 

 mudstones, and sandstones, with a thickness of 10 feet. Beneath 

 this are coarse ashes 12 feet thick, resting on an agglomerate [602] 

 containing rounded or subangular fragments of pinkish felsites, 

 varying from small chips to pieces 6 inches or more in diameter, 



1 Portlock, 'Rep. aeol. Londond.' 1843, pp. 262, 283, etc. ; M'Coj, ' Syn. Sil. 

 Foss. Irel.' 1846, pp. 7, 16, 26, etc. 



^ Mem, Geol. burr. dec. ii, vii & xi ; Monogr. Paljeont. Soc. 'Brit. Trilob.' 

 pp. 82 & 140. 



^ Monogr. Palaeont. Soc. ' Brit. Silur. Bracb.' vol. iii, pp. 38, 50, 78, etc. 



is Jamesii, M'Ooy. 

 ^Ampyx mammillatus, Sars. 



costatus, Sars. 



^Asaphus sp. 



Calymene duplicata, Murch. 

 ^ Cybele cf. bellatula, Dalm. ? 



cf. rex, Nieszk. 



McHenryi, sp. nov. 



Harpes Flanagani, Portl. 

 ^Lichas laxatus, M'Coy ? 



Barrandia Portlockii, Salt. 



Spharexochus mirus, Beyr. 

 * Tritmcleus hibemicios, Reed. 



Turrilepas scotica, Nich. & Eth. 

 ^ Orthis argentea. His. 



