790 HISTORICAL GEOLOGYo 



CJiaracteristic Species. 

 1. Lias. 



1. Lower Sinemurian. — Ammonites (uEgoceras) planorbis, A. (Coroniceras) Buch- 

 landi, Ostrea Liassica, Gryphcea arcuata^ Lima gigantea, Hippopodium iwnderosum, Spiri- 

 ferina Walcotti, Isastrcea Murchiso)ii, Pentacrinus (Extracrinus) Briareus, Ichthyosaurus, 

 Plesiosaurus. The " White Lias " or Hettangian, beneath the Sinemurian, or at the top of 

 the Khsetic, contains Ammonites planorhis, A. Burgundice, Cardinia Listen, C. concinna, 

 Becten Valoniensis. 



2. Middle Liassian. — Ammonites (Amaltheus) spinatus, A. (A.) ibex, A. (^goceras) 

 Jamesoni, Belemnites paxillosus, B. clavatus, Gryphcea obliqua, Avicula ino&quivalvis, 

 Inoceramus substriatus, Plicatula spinosa, Pentacrinus subangularis. 



3. Upper Toarcian. — Ammonites (Harpoceras) serpentinus, A. (Harpoceras) bifrons, 

 A. (Lytoceras) Jurensis, A. {Harpoceras) radians, Nautilus Jurensis, Belemnites vulgaris, 

 Leda ovum, Posidonomya Bronni, Bhynchonella pigmcea, Cadomella, Spiriferina, Pseudo- 

 diadema Moorei, Extracrinus Briareus, Ichthyosaurs, Plesiosaurs, Teleosaurus Chap- 

 manni (at Whitby) . 



2. Oolyte. 



1. Lower Oolyte. — (1) Bajocian. Tlie subdivisions recognized in England are 

 those of ^mmoniYes (Harpoceras) 3Iurchisonce, Lower; ot Stephanoceras Humphriesianum, 

 and Cosmoceras Parkinsoni, Upper. In Europe: (a) A alenian, with Amm. {Harpoceras) 

 Murchisonoi, Bhynchonella subangulata, Terebratula perovalis, T. fimbria, Pecten lens, 

 Pholadomya fidicula. (b) Bajocian, witli Amm. {Stephanoceras) Humphriesianus, A. 

 (Cosmoceras) Parkinsoni, Astarte obliqua, Trigonia costata, Gryphcea sublobata (Gryphcea 

 beds), Ostrea Marshii, Bhynchonella spinosa, Terebratula perovalis. 



(2) Bathonian. (a) Vesulian or Euller's Eartli, with Amm. discus (and up to Corn- 

 brash), A. Herveyi (and up to Forest Marble), A. ferrugineus, Anabacia hemisphcerica, 

 Pecten vagans, Ostrea acuminata, Bhynchonella varians. (b) Bradfordian, or Great (or 

 Bath) Oolyte, with Am^n. macrocephalus, A. aspidioides, Ostrea 3Iarshii, Pecteri lens, 

 Bhynchonella decorata, B. concinna, 3Iegalosaurus, Cetiosaurus, Pterodactylus, Wald- 

 heimia digona, Steneosaurus ; and in the Stonesfield slate, at the base, with many plants, 

 Ostrea Sowerbyi, Bhynchonella obsoleta, Gervillia acuta. Ichthyosaurus, Plesiosaurus, 

 Teliosaurus, Bhamphorhynchus, Testudo Stricklandi, Chelys Blakei, 3Iammals. In Russia 

 the Oxford Oolyte is overlaid by beds called the Volgian. 



2. Middle Oolyte. — (1) Oxfordian. (a) Callovian or Kellaways Rock, with 

 Amm. Goiverianus, A. macrocephalus, Belemnites Oweni, B. hastatus, Gryphcaa bilobata, 

 G. dilatata, Trigonia paucicosta, Terebratula digona. (b) Oxfordian or Oxford Clay, 

 with Amm. Lamberti (up to Kimmeridgian), A. 3Iarice, Trigonia clavellata, Becten 

 vagans, Avicula incequivalvis, Bhynchonella socialis. 



(2) Corallian. (a) Argovian, Sponge-bearing beds, Seyphian-Kalk, and those of 

 Amm. ca7ialiculatus. (b) Corallian, divided into Bauracian or Glyptician, with Glypticus 

 hieroglyphicus, Amm. bimammattis, Thecosmilia annulata. (c) Isastrcea explanata and 

 Diceratian, with Diceras arietinum, Nerinea Defrancii. The Coral Rag and Corallian 

 Oolyte of the Corallian contain Amm. plicatiUs, Thamnastrcea gregaria, T. concinna, 

 Cidaris florigemma, Hemicidaris intermedia, Pseudodiadema hemisphcericum, Avicula 

 ovalis, Lima rudis, Perna inyliloides; and the underlying Lower limestones, Amm. 

 cordatus, Avicula ovalis, A. expansa, Pecten fibrosus. 



3. Upper Oolyte. — (1) Kimmeridgian. (a) Sequanian or Astartian, with Astarte 

 minima, A. supracorallina, A. gregaria, Ostrea deltoidea, Bhynchonella corallina, Amm. 

 mutabilis, A. deeipiens, A. tenuilobatus, Pseudodiadema hemisphcericum, Cidaris 



