240 Geological Society of London. 



a single example ; its head is remarkable on account of its obtusely 

 pointed triangular form and prominent marginal eyes. 



In conclusion the author made some observations on the structure 

 of Pterycjolus, showing that it possessed a series of branchial plates, 

 — leaf-like bodies presenting a highly vascular and delicate struc- 

 ture, arranged in a linear series of from six to eight in each row, 

 and appearing to have occupied a position beneath the thoracic plate 

 on the ventral surface of the body, as seen in Limulus at the present 

 day. He also suggested that Pterygotus perornatus and P. crassus are, 

 possibly, both varieties of P. bilohus ; they are all possessed of a 

 bilobed telson or tail-plate. 



2. " On the Coniston Group." By Professor R. Harkness, F.R.S., 

 F.G.S., and Dr. H. A. Nicholson, F.G.S. 



The object of this communication v^^as to record the occurrence of 

 a new and unique horizon, containing a rich Graptolite -fauna, in that 

 portion of the Silurian series of the Lake-district termed the Conis- 

 ton-flags by Professor Sedgwick. The authors also gave a detailed 

 description of these flags, and pointed out their physical and palas- 

 ontological relations with the Coniston Limestone below, and the 

 Coniston Grits above them. 



The palgeontological relations of the Coniston Limestone and of 

 the underlying green slates and porphyries have been previously 

 shown to be those of the Bala and Caradoc group. The mudstones 

 succeeding to the Coniston Limestone yield an entirely new fauna, 

 including six species of Diplograpsus, all of ^which, with one ex- 

 ception, are in Britain characteristic Upper Llandeilo forms ; and the 

 evidence of the other species is in the same direction. In Ireland, 

 however, many of these species have been obtained from strata of 

 Caradoc age. The fossils of the Coniston Grits have very little 

 affinity with those of the Kendal Flags, nor do they exhibit such a 

 facies as would connect them with the lower members of the Upper 

 Silurian series. Palaeontologically, therefore, this Coniston series 

 must be looked upon as a continuous group of rocks, and the phy- 

 sical evidence leads to the same conclusion. There is, thus, in the 

 Lake-district, a greater development of Caradoc and Bala rocks 

 than is to be found elsewhere in the British Islands, as we are now 

 required to add a great thickness of strata, possessing, on the whole, 

 a decidedly Lower Silurian fauna, but containing some new forms 

 of life in its higher portions. 



3. " Death of Fishes on the coast of the Bay of Fundy." By Dr. 

 A. Leith Adams, F.G.S., 22nd Regiment. 



On the 24:th of September, during a heavy gale from the west, 

 impinging almost straight on to the entrance of the Lagoon, known 

 as Anderson's Cove, enormous numbers of fish were observed floating 

 dead upon the surface of the water, and thrown up in quantities by 

 the waves. On the gale subsiding, the whole surface of the lagoon 

 and its banks were covered with dead fish, to the depth of a foot in 

 some places. It was evident that the shoal had been literally ground 

 to pieces against the rocks by the force of the waves. In conclusion 

 the author referred to the vast quantities of fossil fish found in the 



