ii. 53, 97;

subdivisions of, in S. W. England, 94; volcanic phenomena of, i. 46; ii. 55; lavas and tuffs of, 57, 58; vents of, 62, 67, 70, 96; sills of, 91, 100 Permo-carboniferous strata, ii. 54 Petersen, Dr., i. 275, 336 Phillips, J., i. 133, 170, 205, 238; ii. 3 ---- J. A., i. 260, 261 ---- W., i. 171; ii. 95 Phonolite, i. 380 (analysis); ii. 375 Phyllite, i. 162, 222 Picrite, i. 377, 417, 420, 448, 450; ii. 57 ---- type, i. 418 Pillow-structure in lavas, i. 26, 184, 193, 201, 240, 244, 252;