Miss C. A. Raisin—Greenstones & Schists of S. Devon. 265 
prolonged in a south-westerly direction towards Croghan Kinshelagh. 
A specimen, collected from a spot one mile north of the summit of 
this mountain, proved, on examination with the microscope, to be a 
typical epidiorite. The rock forming the summit itself has under- 
gone more alteration. It has a marked foliated character, and 
consists mainly of chlorite and “felspar-mosaic.” Sphene is also 
present in abundant grains. . 
Specimens of epidiorite were also collected about a mile N. of 
Wicklow, on the §.W. side of Croghan Kinshelagh, and from a small 
atch of greenstone two miles east of Kilcavan House, to the east of 
Shillelagh (Sheet 1388). 
(f.)—In only one case was the occurrence of a serpentinous green- 
stone noted. My attention was drawn to this rock by Mr. Kinahan. 
A small patch of it occurs about half a mile west of the patch of 
epidiorite referred to above, two miles east of Kilcavan House, near 
Shillelagh. Unfortunately I was prevented by lack of time from 
visiting the locality myself, and the specimen examined was 
collected by Mr. Clark. The rock is of a variable green colour, 
and has the characteristically soapy “feel”? of a serpentinous rock. 
A microscopic section discloses the serpentine in colourless layers, 
associated with grains of opaque iron-ore and a finely granular 
substance resembling calcite or dolomite. The powdered rock, treated 
with hydrochloric acid, effervesces only on warming; it contains, 
therefore, as we should expect, the magnesian carbonate. 
The texture of the serpentine is well brought out between crossed 
nicols. It has rather the “netted” or “bladed” structure of 
serpentine derived from augite than the “lattice ”-structure 
peculiar to that mineral when produced by the alteration of horn- 
blende. 
Whatever may be the nature of the alteration, there can be little 
doubt that we have here the final product of the alteration of a 
greenstone (dolerite). As we have seen above, the usual course of 
the metamorphism of the Wicklow dolerites is, first, the formation 
of a hornblendic rock (epidiorite, hornblende-schist) and, finally, 
a chlorite-schist; but the case in point indicates that there are 
exceptions to this rule. 
28, Jermyn Street, 8.W. 
VI.—Devontan GrReEnstones AND CHLOoRITE ScHists oF SovurTH 
DEVoN. 
By Miss C. A. Ratstn, B.Se. 
ie a paper published in the Devonshire Transactions for 1888 
(p. 215), Mr. Somervail suggests the identity of the chlorite 
schists of South Devon with certain rocks to the northward. As 
this hypothesis (could it be established) would have a most important 
bearing on subjects of controversy, I took the opportunity in a few 
days this winter, to visit and collect from these localities, including 
the dyke nearest to Torcross. I was not rewarded by finding any 
striking similarity to the metamorphic rocks of the south. In that 
