550 Ralph Tate — New Secondary Brachlopoda. 



clay, is absent in the county of Wexford, having been removed by 

 denudation. 



The middle sands and gravels of Norfolk, have also been subjected 

 to denuding influences. It is, however, in the south-east of Ireland, 

 that this member of the'series exhibits the influence of denudation in 

 a high degree. Here the rounded outline of these deposits is the 

 result of this influence ; and here too we have evidence justifying 

 the conclusion that the upper Boulder-clays have to a very great 

 extent been removed by this cause, since we have this upper 

 portion of the series preserved in a few localities only. 



No doubt very considerable changes have been effected in the 

 several deposits which constitute the Pleistocene group, since the 

 period of their deposition, by the agency of atmospheric causes. 

 These causes fail, however, to account for the entire absence of one 

 or other member of the group iu some localities ; and it seems much 

 more probable that the influences of marine currents, during changes 

 in the relative level of land and sea, were the denuding agents, 

 rather than atmospheric causes, such as are now in operation over 

 the several areas where the Pleistocene deposits occur. 



Y. — Additions to the List of Bbaohiopoda of the Bbitish 

 Secondaky Eocks. 



By Ealph Tate, Assoc. Lin. Soc, F.G.S. 



SIXTEEN years have now passed since Mr. Davidson's Mono- 

 graph of the British Secondary Brachiopoda appeared, and as 

 numerous additions have been made from time to time, it is my 

 present object to collate the scattered records of the additional 

 species, and to supplement such information by notices of new or 

 little known forms. 



Part I. — Liassic Species. 



The number of British Liassic Brachiopoda known to Mr. David- 

 son was forty ; of these Leptcena granulosa is now considered to be a 

 Placunopsis, L. Pearcei is referred to the genus Monotis ; Discina 

 Townshendi finds a habitat in the Ehgetic . series, and Discina reflexa 

 and Lingula Beanii should be removed to the Inferior Oolite ; but 

 this number has been greatly augmented, chiefly by the researches 

 of Mr. Charles Moore. The fact of such a large number of species 

 having been overlooked finds an explanation in the greater num- 

 ber of workers upon the Liassic formations ; this is true not only 

 for the Brachiopoda, but for other forms of animal life ; thus the 

 fauna of the Lias numbers 1,103 species, whereas 426 species only 

 are catalogued by Professor Morris in his second edition of British 

 Fossils, published 1854. The Lower Lias, which was somewhat 

 characterized by a paucity of Brachiopodous shells — two or three 

 species only being well known, has now yielded eighteen species. 



1. Waldheimia perforata, Piette, sp. Bull. Soc. Geol. Fr., 

 vol. xlii., 1856. Terehratula strangulata, Martiu. T. psilonota, 

 Quenstedt. 



