416 BEPORT— 1888. 



50. Tywyn Railway Cutting — Ditto, more altered (fig. 23). 



51. South side of inlet, Four Mile Bridge — Serpentine derived from saxonite. 



52. Valley, near Cruglas -Ophicalcite derived from Iherzolite. 



53. Cruglas — Ophicalcite from limestone. 



54. Pwll Clai, north of Roscolyn — Talcose schist. 



55. Llyn TrefwU — Cataclastic granite. 



56. Llyn Trefwll — Diabase. 



57. Llyn Trefwll — Slightly schistose diabase. 



58. Llyn Trefwll — Diorite with fragment of granite. 



59. Bottom of Gogarth — Medium-grained grit. 



60. Flaggy beds at South Stack— Fine-grained rock, with foliation oblique to 



both bedding and cracks. 



61. Slaty, Porth-da-farch — Medium-grained rock, mylonised. 



62. Porth-y-crug — Fine-grained rock, with strain-slip cleavage, against a cylin- 



der of grit (? a worm casting) (fig. 16). 



63. Porth-y-crug — Medium-grained grit. 



6i. Porth-y-gwalch — Quartzite, showing fracture cleavage, zircons. 



65. Roscolyn — Quartzite, showing fracture cleavage, zircons. 



66. South of Roscolyn — Microspectral schist with fracture cleavage, rutiles (fig. 9). 



67. Roscolyn slate — Confused microspectral schist with few fragments, some of 



mica, chlorite transverse in nests. 



68. Green rock, north side of Borthwen — Epidote crystals in dark dust. 



69. Gwalchmai Lowest, west of stream — Gneiss, with laminar orientation, and 



microcline, &c., in cracks (fig. 8). 



70. West of Gwalchmai — Cataclastic gneiss. 



71. Gwalchmai Turnpike — Coarse mica schist, with linear orientation. 



72. Bodwrog Church — Gneiss with laminar orientation. 



73. Road north of Pen-y-carnisiog — Gneiss with laminar orientation. 



74. Porth-y-ly-wod Island — Coarse mica schist with linear orientation. 



75. Porth-y-fawch — Fine mica schist with quincuncial orientation (fig. 5). 



76. PoTth Gwyfen, east side — Gneiss with few remaining fragments. 



77. Llangwyfen — Fine mica schist with quincuncial orientation. 



78. North of Llangwllog stream — Gneiss with laminar orientation, very little 



mica. 



79. South of Llangwllog stream— Cataclastic gneiss. 



80. Y Foel, Llanerchymedd— Sericitic gneiss. 



81. Gorse Mill, South of Llanerchymedd — Decomposed gneiss with derivative 



mica (fig. 2). 



82. By Llanfaelog Church— Fine felted mica. 



83. Ease of Porth-ceryg-defaid— Fine cataclastic quartz-felspar mosaic. 



84. Nearest gneiss, Porth-y-ly-wod— Cataclastic gneiss. 



85. Between Ty Croes and Llanfaelog— Fine-grained, micaceous, with larger 



fragments. 



86. Gwalchmai, between granites — Quartz-felspar mosaic. 



87. North side of Llangwllog — Cataclastic quartz-felspar mosaic. 



88. West of Bodorgan — Dislocated cataclastic rock. 



89. Lump in ashy bed, Llancadwaladr — Coarse quartzose fragpnental rock. 



90. In gneiss, west side of Trecastle Bay — Large orientated calcite. 



91. Bodwrog— Irregular large calcite. 



92. Behind Druid Inn— Coarse mosaic limestone. 



S3. Railway Cutting, north of Llangwllog — Volcanic tuff, with mica of two 



generations, the first with inclusions. 

 94. South of Cerrig Ceinwen — Fragments of calcite and jasper in calcific 



cement. 



93. In limestone south of Cerrig Ceinwen— Jasper of small siliceous elements. 



96. Quartzknob, Bethel, Bodorgan — Large rounded quartz fragments with needles 



in a polygonal quartz matrix. 



97. Quartz knob, east of Llangefni — Various rounded fragments in pure quartz 



matrix. 



98. Cerryg-ddwyffordd — Fine-grained rock. 



99. Cerryg-ddwyffordd — Fragmental rock. 



100. Just north of Llangefni — Fine-grained rock. 



101. Further north of Llangefni — Dislocated and cataclastic. 



102. Side of River Cefni— Fine-grained rock, spectrally polarised. 



