rex Iii 



INFERIOR OOLITE AMMONITES 



opalinum, Lioceras, 12, 13, 21, 43-52, xxxv, xxxix, 

 xli, xlii, \lv, exxx, cxli, cxliii ; selected as type 

 of genus, 12 ; correction, xli ; confounded 

 with Cypolioceras opaliniforme, xlv 



Opalinum zone, 2, 4-7, 43, 45, 46, 51, 52, 53, 163, 

 166, 222, 223, 282, 291 ; localities where 

 found, fossils of, 10 ; geology of, 41 ; occur- 

 rence in several countries, 53 



opalinum, var. comjptum, Lioceras, PI. 13, fig. 11. 

 see partitum, Lioceras ; PL 14, figs. 1, 2, sp., 

 Lioceras; PI. 14, figs. 3, 1, partitum, L. ; PL 

 I /', figs, v, 6, plicatum, Cypholioceras ; p. 53, 

 see spp. above 



Opalinum, var. comptum, Harpoceras, 54 



Opalinus, remarks concerning mistaken identifica- 

 tion of, xli ; Ammonites, 14, 35, 47-53, 127 

 255, xxxvi, xli, clxxxii ; Am., Quenstedt's 

 confusion about, xxxv 



opalinus, zone of, 49, 51 



Opalinus beds, necessity for correction concerning, 

 xxxv ; term rejected, xxxv 



opalinus, Nautilus, 35, xxxvi, xli 



opalinus costosus, Ammonites, 102, xxxvi, xxxviii 



Ophioceras, 13, 201, 232, 233 



Opis, 45 



Oppel, Dr. A., 2, 17, 49, 87, 117, 146, 155, 156, 

 170, 173, 189, 192, 205, 304, 306, vii, viii, 

 xvii, xviii, xxix : on Jurassic Hocks, 2 ; his 

 zones, 49; Am. jurensis, 51 ; mistake about 

 carina, 156 



Oppelia, 14, 40, 140,217, 295; not derived from 

 Arietites, 130 ; discus 



Oppelidae, exciv; radial lines, exevi 



Opposite lateral lobules, 364 



Orbigny, A. d', 9, 17, 55, 60, 86, 117, 121 , 124, 146, 

 148, 153, 169, 170, 184, 188, 192, 215, 217, 

 219, 241, 304, 305, 309, vii, viii, x, xxiii, xxvii, 

 exxxii, exxxvii ; on subdivision of Ammonites, 

 10 ; on Am. primordialis, 55 ; on Am. con- 

 cavus, 60, 86 ; on Am. cadomeusis, 120 ; on 

 Am. cycloides, 124; and Am. radians, 187; 

 ami A. discoides, 217 



Orbignyi, Grarn/moceras, PL 27, figs. 3—6, p. 184, 

 see orbignyi, Phlyseogrammoceras 



Orbignyi, Grammoceras, 183, civ 



orbignyi, Phlyseogrammoceras, PI. 27, figs. 3-6, 

 p. 184 (Grammoceras Orbignyi) ; Suppl., Fig. 

 135, p. clxvii ; p. civ 



Ornament, importance of character of, i ; manner 



of, not the kind important, ii ; (test), excix ; 



acme, cc ; intersection of, cc ; longitudinal, 



cc ; transverse, cc; elaboration, acme of , cc ; 



longitudinal examples of, cci; on periphery, cci 

 Ornaments, 270 



Ornamentation, iv ; as criterion of affinity, ii 

 Ornate, iv, viii ; see also crassornate, insequi- 



ornate, irregulari-ornate, lrcvigate, parvi- 



ornate, regulari-ornate 

 Ornatilobate, v 

 Ornatus beds, xl 

 Orthoceras, cci, ccii 

 Ostrese, 455 



Otley Hill, 40, 52 ; strata of, ccvii 

 Outcoiling, civ 

 ovalis, Sonuinia, 315 

 ovatum, Grammoceras, 163 

 Overbury, clvi, clxi 



ovum, Leda, upper beds of, date of, xv 

 Oxford, 53 



Oxford Clay, 131, 133, xl 

 Oxfordshire, 52, ccvii 

 Oxyuoticeras, 45, 225, 226 ; discoides, oxynotum ; 



from Hudlestonia, 225 

 Oxynotoceras ; oxynotus 

 oxynotum, Oxynoticeras, 227, 230 

 oxynotus, Ammonites, 226 ; Oxynotoceras, xl 

 Oysters, 43 



pachu, Pseudogrammoceras, PI. 34, figs. 1, 2, p. 

 203 (Grammoceras Samianni) ; Fig. 147, p. 

 clxvii, p. cli 



Pachygyralj iii, exevii 



pagana, Welschia, PI. 12, figs. 5-7, p. 25 ( Lio- 

 ceras bradfordense var. giganteum) ; Suppl. 

 PI. 11, fig. 32, p. Iii 



Paine, Dr. T., and Paineia, lxxvi 



Paineia, Suppl., p. lxxvi ; nitens 



Paineia, from Lucya, Depaoceras, lxxiv ; classifi- 

 cation, exeviii 



Painswick, 9 k 96, 100 



Palseontological hoi'izons, confusion, xv ; pheno- 

 mena, xii 



Palaeontology, 10; geological importance of cor- 

 rectness in, 342 ; confusion and difficulty 

 caused by incorrect, 342; geology marred by 

 " sufficiently near " identification, 342 



