224 TRANSACTIONS, NATURAL HISTORY SOCIETY OF GLASGOW. 



action going on in the Firth of Forth. This form of deposit, 

 which often makes up extensive banks or reefs, can be traced for 

 a considerable distance along the coast, till it passes oflf into 

 siHceous sands, sandy muds, sand, mud, and shells, or ooze of the 

 open sea, where life on the bottom is more prolific. 



The deposits found over the areas of Stations VII. and VIII. 

 may be taken as typical offshore transitional forms on account of 

 their variation, for instance, at the west end of Station VII. and 

 south-west end of Station VIII. a fine-grained, reddish-coloured 

 siliceous sand is found, which gradually emerges into a 

 homogenous plastic mud at points farthest from the coast line. 



The deposits found at Station IX. consist of a typical marine 

 shallow-water mud, although on its surface distinct traces of the 

 brown, fine argillaceous material was observed, clearly demon- 

 strating, which all my observations go to prove, how this deposit 

 of fine mud is being laid down over the floor of the firth, 

 diminishing gradually as the open sea is reached. 



A marked feature in all the deposits examined by me between 

 Inchkeith and the May Island is their impurity, the amount of 

 detrital, decaying organic matter and dead remains of animals 

 they contain. Marine life on the whole is found more abundant 

 at Station VII., the deposit itself much cleaner and healthy 

 looking than those found at Stations I. to VI. At Station VIII. 

 the purity of the deposit and amount of life was found more 

 striking (see lists of animals obtained at this station, and 

 compare with others), and even more so at Station IX. where 

 comparatively little foreign material was observed. It will also 

 be observed that marine life was found to be more prolific at this 

 station than at either of the others. 



mouth ofthrrirth of Forlh tJiroasli Vic/s/eifAfajf. 



