Per 



298 



Periods, palaeontological, xvi. p. xliii. 

 Periscliodomus, gen. char, of, xxx. 312 ; 

 xxxii. 35. 



hiserialis, xxxii. 36 & pi. iii. 



Perischoechinida tessellata, group denned, 



xxxii. 40, 399. 

 Perischoechinidae, relat. w. Echinothu- 



ridse, xxx. 307-316 & pi. xxiv. 

 Perisphinctes Davidsoni, sp. nov., xxxvii. 

 602. 



Martinsii, xxxvii. 602 ; xxxviii. Proc. 



234. 



pygmceum, xxxvii. 602. 



Perissodactyla, char, of, iv. 131 et seqq. ; 



remains in Wookey Hole, xix. 271. 

 Perlite fr. Schemnitz, cross-hatched fel- 

 spar in, xxxi. 480 & pi. xxiii. ; struct, of 

 recent, xxxiii. 451 & pi. xx. ; of ancient, 

 xxxiii. 453-455 ; devitr., xxxiii. 455 & 

 pi. xx., xli. Proc. 94 ; in lavas of Y 

 Glydvr Fawr, xxxv. 508-510 fie. ; pre- 

 Cambr., of Porth Hayog, xl. 307; 

 altered, fr. Llanberis Pass, hollow sphe- 

 rulites in, xli. 167 & pi. iv. 

 Perlitic structure in Hungar. rhyolites, 

 xxxii. 300 ; in ' obsidian sandst.,' orig. 

 of, xxxvii. 396 et seqq.; in devitr. ob- 

 sidian, xliii. 500 & pi. xxi. ; in Beddgelert 

 spherulitic rock, xxxvii. 404_ & pi. 

 xxi. ; traces in basalt-glass, xxxix. 451 ; 

 in dacite-glass, xlii. 429; in tuff of 

 Craig-y-Llam, xlv. 430 fig. ; strain in 

 conn, with, xl. 340-346 & pi. xviii.; 

 cracks filled w. alterat.-products, in 

 variolite, xliv. 307 & pi. xi. (microsc. 

 sections); cracks in quartz, 1. 367-375 

 figs. & pi. xviii (microsc. sections) ; 

 perl, felsites, prob. Archaean, fr. flanks 

 of Herefordsh. Beacon, xliv. 740-744 

 & pi. xvii. ; do. of Caradoc, xlvii. 540 & 

 pi. xix. ; spheroids & concentric struct, 

 in nodules, xlv. 255 ; perl. & spheral. 

 obsid. fr. Pil as, xlvii. 530-533 & pi. xviii. 

 (microsc. sections) ; perl. & spheral, 

 struct., sequence of, 1. 10. 

 Permanence of ocean-basins, xlvi. Proc. 



59-110. 

 'Permeation area' (N.E. Forfar), xlix. 



331. 

 Permian in Russia, etc., i. 81-87; gene- 

 rally, ii. 181-182; in Saxony, v. 1-4, 

 xiii. p. cxxvi ; at Astley, vii. 268-271 

 w. chem. anal. ; of Clevedon, ix. 285 ; 

 limits of, x. p. xl. 

 Permian breccias of Shropshire, etc., xi. 

 185-205, xii. p. Iv ; deposits of Thiir- 

 ingerwald, xi. 420; in Harz, xi. 443; 

 in W. Europe, xii. 63 ; of Odenwald, 

 xiv. 221 ; of N.E. Bohemia, xix. 297- 

 306 ; equivs. in Malaga district, xv. 591 ; 

 breccias & sandst. in S. Scotland, xii. 

 138-140, 254-267; & in Cumberland, 

 xviii. 205-218, xxxvii. 286-298 & pi. xi 

 (map) ; foss. fr. Durham, xiii. 213-218 & 

 pi. vii., xx. 345-358 & pi. xviii. ; gen. 

 section ibid., xx. 347 ; synopsis of rocks 

 ibid., xliv. 767 ; limest. in Tyrone, xiii. 

 p. cxxviii ; Perm, of England & Germany 



correl,, xiv. p. cxliii, 225 : distrib. of Lr. 

 in Central England, xvi. 64; Perm, at 

 Shireoak, xvi. 139 ; of S. Yorks & its 

 palaeont. relats., xvii. 287-325 & pi. vii. ; 

 of N.W. England, & extens. into Scot- 

 land, xx. 144-165 ; claim to be entitled 

 a system, xvi. 412-421 ; Perm, in Bolivia 

 & Peru, xvii. 36; foss.fr. Queensland, 

 xviii. 246 ; Perm. Chitonidae, xv. 607-625 

 & pi. xvi. ; change in char, of sediments, 

 xviii. 130; Palaeoz. aspect of fauna & 

 flora, xix. 160 et seqq. ; Brit., relat. to 

 rocks above & below, xix. p. xlviii ; blanks 

 in rock-success, w. Perm, roof, xx. 

 215. 

 Permian (Lr.), nr. Harrogate, xxi. 234; 

 of N.W. Engl., *Murchison & Hark- 

 ness's paper, xxi. p. lxi ; rocks, in relat. 

 to Carb. in Pendle Range, xxiv. 327 et 

 seqq. ; varieg. sandst., chem. anal, of, 

 xxiv. 360; do. marls, chem. anal, of, xxiv. 

 364, 365, 385; beds of Salopian type, 

 xxv. 172 ; do. of Lanes type, xxv. 

 175 ; typ. diff. betw. same. & its 

 poss. cause, xxv. 177; age of Plumpton 

 Grit, xxv. 291, 294 et seqq. ; of Midde- 

 ridge, Lepidotosaurus fr., xxvi. 556-564 

 & pi. xxxviii. : Proterosaurus fr., xxvi. 

 565-572 & pis. xxxix.-xl. ; Ptoryptevtis 

 fr., xxvi. 623-641 & pis. xlii.-xliii. ; 

 breccias & boulder-beds of Armash, 

 xxix. 402-407 figs. ; 'Boulder Clay' in 

 Natal, xxvi. 516; upheaval in Perm, 

 times, xxvi. p. Ixiii; phys. cond. indi- 

 cated by Perm, strata, xxvi i. 245; of 

 E. Nova Scotia & Prince Edward I. in 

 relat. to Upper Coal-format., xxx. 209- 

 219 figs. 

 Permian age of Talchir Group, xxxi. 528 ; 

 Perm, of other regions besides S. Africa, 

 contg. theriodontia, xxxii. 352-363 figs. ; 

 of N.E. England, & its relat. to oveiiyg. 

 & underlyg. formats., xxxii. 533-537; 

 Perm, in relat. to Upper Carb. of Den- 

 bigh & Shropshire, xxxiii. 10-28 & pi. i 

 (sections) ; (Lr.) age (?) of Whin Sill, 

 xxxiii. 420 ; strata at S. Scarle, xxxv. 

 812, 813; (Upper) of Orenburg, CliorM- 

 sodon fr., xxxvi. 540-543 fig. ; do. of 

 Kargalinsk, foss. fr., xxxviii. 490-501 w. 

 sections & pis. xx.-xxi. ; of Central 

 Europe, xl. 389-403 figs. ; gen. relat. of 

 group to older members of Palaeoz. 

 Series, xl. 396 ; gen. relat. to Trias, 

 xl. 398; Perm. spp. of Bairdia, list of, 

 xxxv. 579. 

 Permian (?) breccias of Leicester & S. 

 Derby, fossilif. nodules & fragm. of 

 iron-ore fr., xli. Proc. 109; glac. 

 orig. of breccias ibid., xlvi. Proc. 114 ; 

 breccias of Leicester coalfield, xlv. 1-40 

 figs. & pi. i (section) ; of S. Devon 

 coast, xliv. 157, xlviii. 62, 75 ; age of 

 'Lr. Red Sandst.' of Devon, xlviii. 72; 

 marls, junct. w. pebble-bed at Budleigh 

 Salterton, xliv. 155 fig. ; ostracoda in 

 England, xlii. 505 & table facg. 506; 

 vole, rocks in Brit. Is., xlviii. Proc. 147 ; 



