47 
Pisces. 
Scymmis spinosus. 
Gadus cellarius. 
Mustelus vulgaris. 
Gadus luscus. 
Acanthus vulgaris. 
Gadus merlangus. 
Pterocephala giorna. 
Gadus pollachius. 
Raia radiata. 
Gadus carbonarius. 
Raia ruaculata. 
Lota molva. 
Raia clavata. 
Hippoglossus vulgaris. 
Raia circularis. 
Rhombus maximus. 
Raia acus. 
Rhombus lsevis. 
Squatina vulgaris. 
Pleuronectes platessa. 
Cottus groenlandicus. 
Pleuronectes limanda. 
Cottus scorpius. 
Pleuronectes microcephalus. 
Trigla hirundo. 
Pleuronectes flesus. 
Trigla lyra. 
Solea vulgaris. 
Trigla gurnardus. 
Clupea herengus. 
Gadus morrhua. 
A.ngui!la conger. 
Gadus seglefinus. 
IX. 
On Denudation. 
By C. F. Ravts. 
Mead at the General Meeting, November Zrd, 1870. 
[This paper included one previously read before the Geological Section. 
The following is an abstract of parts not before reported.] 
The importance of Denudation in connection with geological history 
can scarcely be exaggerated. Great wasting agencies have always been at 
work, wearing away the surface of the land. Tho action of the sea 
upon the coast, as witnessed by the pebbly and shingly beaches of our own 
shores, and the great blocks seen here and there upon the strand ; the 
denuding power of rivers like the Niagara, which at the great Fall has cut 
its channel backwards through the solid rock for several miles ; the effect 
of torrents and floods; the bursting of natural barriers at the lower 
extremities of lakes ; the wearing influence of rain, frost, &c; these and 
other agencies have modified or removed strata, so as to immensely in- 
