Vol. 58. ] THE FOSSILIFEROUS SILURIAN BEDS OF KERRY. 261 
east of Carrigcam. The appearance of the rock in the field has 
already been described. Under the microscope, it shows a very 
fresh fine-grained matrix, through which are scattered broken quartz- 
grains, afew felspars, and sometimes fragments of pumice recognizable 
by the curving outlines of the cavities. Small zircons and flakes of 
muscovite also occur init. The marked banding seen in some hand- 
“specimens is due to the accumulation of broken quartz-grains along 
certain lines. A somewhat similar rock is exposed on the cliff-face 
opposite Carrigcam. Both these rocks are highly silicified. 
(2) Moderately fine-grained purple ash.—This type of 
rock is widely distributed ; it occurs overlying and underlying the 
big series of rhyolites at Poulnakeragh. It is found also at the 
south-western corner of Clogher Head (B 7) and in the inlet of Car- 
rignaneena (C 6 in part). 
The rock which forms the south-western corner of Clogher Head, 
in a hand-specimen is a compact purple rock, showing many felspar- 
crystals and some signs of parallel arrangement. Under the 
microscope, many broken felspars are to be seen. This rock shows 
signs of crushing, and much calcite is developed in strings along 
parallel planes. Lavya-fragments are not very plentiful; but two 
kinds are present—one of a rock composed of fair-sized felspar- 
crystals, short and square-ended, with very little intervening ground- 
mass ; the other, with numerous larger singly-twinned phenocrysts, 
embedded in a fine-grained groundmass in which felspar-needles 
ean be detected. 
A slightly coarser-grained rock, one of the big series (C 4) of 
sandstones and ashes exposed at Drom Point, is noteworthy for the 
very small amount of fine-grained material between the fragments, 
which are mainly of an andesitic character, and lie closely packed 
jogether. The ash which is exposed in the northernmost of the two 
streams that run down the western side of Croaghmarhin towards 
Clogher village, shows many small pumiceous fragments recognizable 
by the curving outline of the vesicles. 
(3) Fairly coarse ash.—tThis type of ash is widely distributed, 
and may be further subdivided into purple ash and pale ash. 
Purple ash forms the band (B5) well seen along the northern 
slope of Clogher Head, and is met with again at Foilnamahagh, 
Foilavaddia (D5), where it is fossiliferous, and north-east of Carhoo. 
The length of the fragments in this type of ash ranges up to three- 
quarters of an inch, but it is generally somewhat less. No features 
requiring special comment were disclosed by microscopical exami- 
nation. 
Fairly coarse, pale ash may be seen at Foilminnaun (A 6 in part) 
at the points west of Redcliff Cove (A 13), north-west of Owen 
(B14), among the series exposed north of Drom Point (C 4), in 
the stream-course south of Carhoo, and in the band which crops 
out at Poulnakeragh and in the south-eastern corner of Ferriter’s 
Cove (C8). The microscopical characters of these rocks call for 
ater 
