268 Messrs. Hicks and Davies— 
inclose the microscopic “dust.” The felspar, which is crystalline 
with the quartz, is principally a plagioclase. Black dichroic mica 
with a very little of the colourless variety is in frequent but thin 
bands. Garnet, sphene, and magnetite are also diffused, but are not 
abundant.—T.D. | 
[Nore 24.—More compact than No. 15, and less distinctly foliated. 
The quartz here too is preponderant, and crystalline, the individual 
grains being crystallized around and into each other. As a result, 
some of them present an exceedingly irregular form, and partly sur- 
round and inclose other crystalline grains of the same mineral. 
Felspar is sparse, the plagioclase more so, but are intimately crystal- 
line with the quartz. The micas, as in No. 15, are in thin lamin 
or aggregations of laminz, which le in excessively thin bands. 
They are not, however, exclusively confined to these, but thin plates 
are scattered throughout, though all lie approximately parallel to the 
bands. Garnet and sphene are here in minute crystals.—T.D. | 
[Nore 25.—A medium-grained rock, which, on microscopic 
examination, appears to consist of quartzo-felspathic bands with 
thinner bands of mica. Contains also garnets. Under the micro- 
scope, thin sections show a mass of intimately crystalline quartz, 
with some orthoclase felspar so fresh and colourless as to resemble 
adularia. The nearly colourless monochromatic mica is here the 
predominant one, and is in larger groups and lamine than in any of 
the other rocks examined. Minute doubly refracting crystalline 
grains, of a pale straw-yellow colour, are also present. ‘These I 
regard as sphene.—T.D. | 
[Norm 26.—A fine-grained, grey rock, with mica evenly dis- 
tributed. In transverse section, the foliation is not striking. The 
quartz here is very intimately crystalline, grouped in wavy bands, 
rudely lentiform, or lengthened in the direction of the banding. 
Felspar is almost absent, but for a few crystals or crystalline grains 
of a plagioclase. The mica is principally biotite, though a few large 
lenticular groups of muscovite are present. It does not form con- 
tinuous bands, but is intermittent in its foliation. Sphene is in very 
minute crystals, with garnet.—T. D. ] 
[Nore 27.—This is a very micaceous rock, with small lentiform 
quartzo-felspathic nests, resembling an augen-gneiss. It contains 
many garnets. A thin section shows the quartz and felspar 
(plagioclase) to be intimately crystalline, both very clear. The 
predominant mica, biotite, is in well-defined bands of very distinct 
crystal groups, and is sometimes interlaminated with and also 
incloses the muscovite.—T. D. | 
[Norr 28.—A medium-grained crystalline mass of hornblende, 
with a brown mica, and much crystalline yellow sphene. Foliation 
is not very distinct, and is chiefly indicated by the lie of the mica. 
The microscope disclosed a mass of distinct crystals of a green 
hornblende with clear quartz, which, besides being interstitial, is, 
also inclosed in the hornblende, a dark brown dichroic mica, and 
sphene crystals throughout. Felspar is not discernible.—T. D. ] 
