107 
a state of preservation as to be certain of their nature, 
without it be a fucoid in my possession found by Mr. 
Grindley in the drift near Laxey. The first place where I 
thought that I had obtained traces of organic remains was 
in the grey fiaggy slates on the shore near Derby Castle, 
on the south side of Douglas Bay. They consisted of circu- 
lar and oval shaped holes on the surface of the rock, and 
reminded me of Arenicolites, but as they occurred only a 
little above and a little below high water mark, and I could 
not find them down to low water mark, as they ought to 
have been if they had been made by the sea on soft places 
in the rock, they probably are due to the action of boring 
molluscs, or some other cause, and have not been made by 
ancient annelides. But certainly Scolites similar in character 
although much larger in size occur in these last-named 
beds, greatly resembling those mentioned by the late Mr. 
Salter as occurring in the hard sandstone at the base of the 
Lower Llandeilo shales, near Tremadoc, and described by 
him in the Memoirs of the Geological Survey, vol. iii. p. 292, 
pi. X. fig. 27. 
Great difiiculties no doubt occur in distinguishing the 
burrows and castings of marine worms from the tracks and 
trails of bivalve and univalve shells or of a Igse, andin the 
present case, in determining the fossils, I take them to be 
Nemerites and Nereites from their, in my opinion, resembling 
those genera more than any other with which I am ac- 
quainted. The absolute identification of my specimens with 
those given of Sir E. Murchison’s being by no means clearly 
made out. 
In making the railway from Douglas to Castletown 
a bed of laminated slates, of a dark blue colour, dipping 
at a high angle to S.E., was cut through at Oakhill, iu 
Braddan. It was several hundred feet in thickness, and 
occurred between two deposits of grey shales. In this dark 
