32 Geological Society of London. 



Mr. Jukes having, in a late paper, mentioned some glacial grooves 

 observed by him in the valley of the Exe, the author stated his 

 opinion that the *' Grooves " have been formed by the minor contor- 

 tions of the strata, and not by glacial action. 



3. " On Disturbance of the Level of the Land near Youghal, in the 

 South of Ireland." By A. B. Wynne, Esq., F.G.S. 



The object of this communication was to place upon record 

 certain facts connected v^ith alterations of level in the shore of the 

 South of Ireland, near the town of Youghal. The occurrence of 

 submerged peat beneath the Youghal strand shows that considerable 

 alterations of level have taken place along the coast of Youghal 

 Bay subsequently to the formation of the peat which so commonly 

 covers the Glacial Drift of Ireland. The author also inferred that 

 toward the close of the Glacial period the sea was further from the 

 present land than it is now ; that the land then sank to the depth of 

 about 90 or 100 feet, and subsequently rose again, but not to its 

 former level ; and, in conclusion, he pointed out the probability of 

 its undergoing depression at the present time. 



II. December 4th, 1867.— Eobert Etheridge, Esq., F.G.S., in the 

 Chair. The following communications were read : — I. "■ On the 

 Graptolites of the Skiddaw Series." By Henry Alleyne Nicholson, 

 D.Sc, M.B., E.G.S., etc. 



The author first described the geological relations and distribu- 

 tion of the Skiddaw Slates, and noticed their correspondence with 

 the Quebec Group of Canada, and then gave a description of the 

 Graptolites found in these rocks. The genera and their distin- 

 guishing characters are as follows : — 



1. Dichograpsus, Salter (3 species) : possesses a frond, repeatedly 

 dichotomous from a basal stipe into 8, 16, or more branches, each 

 with a single row of cells, the lower part of the stipe being enve- 

 loped in a corneous cup. 



2. Tetragrapsus, Salter (3 species) : possesses a frond composed 

 of four simple stipes, arising from a non-celluliferous funicle, which 

 bifurcates at both ends. 



3. Phyllograpsus, Hall (2 species) : differs from the last in pos- 

 sessing a frond composed of four simple stipes united back to back 

 by their solid axes. 



4. Didymograpsus, M'Coy (7 species) : the frond consists of two 

 simple stipes, springing from a mucronate radicle, which may be 

 rudimentary or apparently absent. 



5. Diplografsus, M'Coy (4 species) : two simple stipes, united by 

 their solid axes into a celluliferous frond furnished with a radicle at 

 the base. 



6. Graptolites vel Graptolithus, Linn. (4 species) : simple stipe, 

 with a single row of cells on one side, and a small, generally curved, 

 radicle at the base. 



7. Pleurograpsus, Nicholson (1 species) : ceUuliferous branches 

 derived from a main celluliferous rhachis. 



II. "On the Fossil Corals (Madreporaria) of the West Indian 



