HARKER : PETROLOGICAL NOTES. 
419 
indeed very marked, and there would be no improbability in the 
transportation of boulders from Eycott to Flamborough : the 
granophyre ("syenite") of the neighbouring Carrock Fell has 
long been known among the Holderness boulders. 
No. 146 must also be placed here It shows the same yellowish, 
striated felspars, rectangular or rounded in outline, imbedded in a 
dark fine-grained matrix, and is ])recisely like specimens collected 
from the great porphyritic lava of Eycott Hill. The slice [1149] is 
very like [1052], although the yellowish-brown pseudomorphs, which 
seem to represent vanished hypersthene, show less distinctive 
characters. As before, the ground-mass consists of very numerous 
httle striated felspars, with abundant magnetite and decomposition- 
products of pyroxene. 
The next specimen, No. 21, shows a dark ground-mass of very 
fine texture, enclosing greenish decomposed felspar-crystals and 
smaller crystals of black augite. It is indeed a porphyritic dolerite 
and would be named " augite-porph)Tite " by some continental 
geologists. 
Micro. [1048]. The porphyritic augites are perfectly idiom orphic 
and almost colourless in the slice. The larger porphyritic crystals, 
belonging presumably to a basic felspar, are completely pseudo- 
morphed by calcite with strings of a green chloritoid mineral. The 
crowded felspars of the gromid-mass are lath-shaped, with twin- 
striation, and seem to be of labradorite or some near variety. They 
have a pronounced arrangement in lines of flow sweeping past the 
porphyritic crystals, though a few of them are included by the larger 
augites. The remainder of the ground consists of little sub-ophitic 
grains ot augite, with greenish and other decomposition-products. 
The slide shows plenty of magnetite, most of which is evidently 
secondary. 
No rock of this kind occurs in situ in the North of England, 
unless it be one of the comparatively little known though extensive 
lavas of the Lake District. On this point it would be rash to 
pronounce. Probably a more thorough acquaintance with the 
volcanic series of Cumberland and Westmorland would enable 
us to detect them in some abundance among the boulders of East 
Yorkshire. 
