268 Geological Society. 



perfectly impressed in a matrix of oehreous earth. Many of the 

 plants are common to both ; hut Ballypalady possesses a whole 

 group of conifers, including a cypress, yew, many pines and firs, 

 not met with elsewhere ; while Glenarm is richer in leafy trees. 

 Among the plants in common are two which still exist, Cryptomeria 

 and a peculiar Pteris with reticulated venation. Among extinct 

 plants the presence of MaccUntoclcia especially points to their age 

 being the same as the Heersian flora of Gelinden in Belgium, a 

 stage very low in the Eocene. The Lough-Xeagh beds are esti- 

 mated to be as much as 500 feet thick, and their flora shows them to 

 be interbasaltic, and therefore Eocene instead of Pliocene as hitherto 

 sometimes supposed. The great extent these beds formerly held is 

 shown by the area over which silicified wood derived from them 

 lies scattered. The basalts, here as elsewhere, have been enor- 

 mously denuded; and the author believes that the horizon of the 

 Mull leaf-bed is not anywhere present in Ireland. The Mull bed 

 is regarded in this paper as probably of about the same age as the 

 Woolwich a.nd Reading series of the London Basin ; it was deposited 

 on the flat banks of a river liable to inundation ; while the Irish beds 

 are fiuviatile, not lacustrine, with the probable exception of those of 

 Lough Neagh, which may be lacustrine. 



December 14, 1SS4. — W. Carruthers, Esq., F.R.S., Vice- 

 President, in the Chair. 



The following communications were read : — 



1. " On the Recent Discovery of Pteraspidian Eish in the Upper 

 Silurian Rocks of North America." By Prof. E. W. Claypole, B.A., 

 B.Sc. Lond., E.G.S. 



Tbe fossils now described from Pennsylvania are the first authentic 

 remains of fishes found in the Silurian rocks of America, and some 

 of them are the oldest undoubted vertebrates yet discovered. Pre- 

 viously fish had not been detected in America below the Devonian 

 Corniferous Limestone of Ohio, and the Lower Devonian of Canada. 



The most important fish-remains hitherto known from beds of 

 Silurian age are from the bone-bed of the Upper Ludlow rocks, one 

 specimen, the oldest in Europe with the exception of Pander's 

 doubtful Conodonts, having been recorded from the Lower Ludlow. 

 The fossils now described are closely allied to the twe Ludlow 

 types and consist of the spines known as Onchus, and the shields 

 referred to Scaj)haspis and belonging to the peculiar family Pter- 

 aspidae. 



The author entered into a detailed comparison of the English 

 Silurian Pteraspids as described by Professors Huxley and Ray 

 Lankester, and those now discovered in America. He described the 

 three layers of which the shields of the Pennsylvanian Pteraspids 

 are composed, and proposed for their reception a new genus, Palce- 

 aspis. He considers the Pteraspidse in which no bony structure 



