830 
Pebidian, Dimetian, and Arvonian 
rocks in Caernarvonshire and An- 
glesey, 295. 
Peckforton hills, Cumberland boulders 
on the, 441. 
and Delamere hills, Kirkeud- 
brightshire boulder-dispersion over, 
435. 
Pembrokeshire, Dr. H. Hicks, on a 
new group of Pre-Cambrian rocks 
in, 285. 
, Mr. T. Davies on the microsco- 
pical structure of some Aryonian 
rocks from, 291. 
Penbryn, microscopic structure of 
rock from, 307. 
Pen-y-lan, Rhymney, and Cardiff, Mr. 
W. J. Sollas on the Silurian dis- 
trict of, 475. 
, fossils from, 479. 
Hill, structure of, 477. 
Pen-yr-heol, section through, 478. 
Perak, tin-deposits of, 229. 
Perlitic and spherulitic structures, 
Mr. F. Rutley on, in the lavas of 
the Glyder Fawr, North Wales, 
508. 
Pernambuco, Mr. J. C. Hawkshaw on 
the consolidated beach at, 239. 
, section opposite the Marine 
Arsenal at, 239. 
Phillips, J. A., Esq., contribution to 
the history of mineral veins, 390. 
Phoca rugosidens, 524. 
Phricacanthus biserialis, 186. 
Pixton Park, section through, 534. 
Plan of aphanitic dyke at Sandy 
Creek, Tambo river, 14. 
of quarry above Yscuborwen, 
Caernarvon, 684. 
of the Wrekin chain, 650. 
of the Parlour Cave, Cresswell 
Crags, 725. 
— showing the relations of the 
Glengariff series, Old Red Sand- 
stone and Carboniferous, in the 
S.W. of Ireland, 713. 
and section of argillaceous and 
crystalline schists near Omeo, 1. 
Plant-remains in the Upper Silurian 
of the 8.W. of Ireland, 7177. 
Plants, fossil, collected in Shetland by 
Messrs. Peach and Horne, 811. 
Platax Woodwardi, 529. 
Pleistocene and Recent deposits of 
North Gippsland, 34. 
history of Cornwall, Mr. W. A. 
EH. Ussher on the, Proc. 6. 
Mammalia, notes on the, of the 
Cresswell Caves, 729. 
notes on the Cornish coast near 
GENERAL INDEX. 
Padstow, by Mr. W. A. E. Ussher, 
Proc. 5. 
Pleurodus affinis, Mr. J. W. Davis on, 
and description of three spines of 
Cestracionts from the Lower Coal- 
measures, 181. 
Pliocene of North Gippsland, 34. 
Potkilopleuron Bucklandi, Mr. J. W. 
Hulke on, identifying it with Mega- 
losaurus Bucklandi, 233. 
Pole Hill, New Brunswick, limestone 
of, 63. 
Polygnathus coronatus, 365. 
crassus, 365. 
cristatus, 366. 
? curvatus, 366. 
— dubius, 362. 
duplicatus, 364. 
? eriensis, 366. 
immersus, 364. 
linguiformis, 367. 
nasutus, 364. 
palmatus, 367. 
pennatus, 366. 
princeps, 365. 
—- punctatus, 367. 
radiatus, 364. 
? serratus, 365. 
—— ? simplex, 367. 
solidus, 365. 
truncatus, 366. 
tuberculatus, 366. 
Pont-a-la-Vieille, section from, to Va- 
lognes, 252. 
Pont-de-Six, section from Valognes 
towards, 252. 
Pontuchaf, section through, 695. 
Porphyries of Snowy River, North 
Gippsland, 20. 
Port Dinorwig, microscopic structure 
of rock from, 305. : 
, and Twt Hill (Caernar- 
you), Prof. T. G. Bonney and 
Mr. F. T. 8. Houghton on the me- 
tamorphie series between, 321. 
Porto do Aleagre, section at, 769. 
Portugal, Dr. C. P. Sheibner on Foy- 
aite, an elzolitic syenite occurring 
in, 42. 
Potosi (Venezuela), altered gabbro 
from, 588; altered dolerite from, 
590. 
Pre-Cambrian rocks, Dr. H. Hicks on 
a new group of, in Pembrokeshire, 
€ 
Dimetian, Arvonian, and Pe- 
bidian) rocks, Dr. H. Hicks on the, 
in Caernaryonshire and Anglesey, 
295. 
rocks in Anglesey and Caernar- 
vonshire, map showing the, 297. 
