336 Yorkshire Naturalists at Saltburn. 
indicating that the Liassic sea at the period when the rocks were 
laid down must have been teeming with life. 
The wasting away of the boulder clay in the neighbourhood 
has left behind much evidence of glacial action. Far-travelled 
boulders from the Cheviots, from the Lake district and from 
Upper Teesdale were strewn in the greatest profusion between 
Saltburn and Huntcliff. Besides igneous rocks from a distance 
and a remote past, there was a curious assortment of very recent 
igneous rocks of strictly local origin, the product of Middles- 
brough blast-furnaces, much of the slag from which is tipped 
at sea. These are not unlikely to give rise to some speculation 
Phota by] {H. B. Booth. 
Skinningrove—showing Coast Erosion. 
amongst scientific contemporaries in the far off age. when that 
coming artistic New Zealander shall sit in solitude on a broken 
arch of London Bridge sketching the ruins of St. Pauls ! 
One of the most striking features of the coast at Saltburn 
is the large conical mound named Cat Nab. _ Its origin is fairly 
evident. The little pre-glacial bay and the two valley streams 
(Saltburn beck and Skelton beck) which flowed into it were 
choked with boulder clay. On the ice receding the two streams 
severally cut there courses in the clay and either entered the 
sea separately in near proximity or joined seaward of the present 
coast-line. As they cut deeper a ridge was formed between 
them. Subsequently this ridge was cut through by the two 
streams approaching each other and Saltburn beck was captured 
Naturalist, 
