\ EOUS nOCK-GB.OVVS— continued. 



Fbeshwate:; Ttpes. 



Life-Chahacteeisiics of ihe difbeeent Systems 

 OE Periods. 



isthorp (Yorkshire) Plant-boda. 



Mammals still low (Marsupials— P/ta.sco^oiAmMwi), but in- 

 creasing; Stereognathus appears to be higher. Elephant- 

 sized- Eeptiles {Megalosaurus) , Flying Lizards, some with 

 ynemhranom y^mgs (Pterodacti/lus), others with fan-shaped 

 feathered wings {Griphosaurus) , and new paddled Saurians 

 (Piiosaurus) , tenanting the land, air, and water respec- 



^jyg^y_ Spec Org ' Plants 0toj)tevis PuIcGozciiTiiO' and 



others allied to Cj'cases ; Shells — Opis, Trigonia clavellata, 

 Myoconcha, Fholadomya Jidiculn, Nerincea, Pvrpurina, 

 Ammonites Humphresianus ; Echinoderms — Apiucrinus, 

 Nudeolites, Acrosalenia ; Fishes — Pycnodus, Strophoduit. 





Period of marine paddled Eeptiles (Icktkyosaiims, Plesio- 

 saurus, Cuttle-fish-snake -sheila {Ammonites — species in vast 

 numbers) and plumose peduncled Star-fishes (Extracriyius) . 



phcea inairva, Leda ovum, Spiriferina, JBelemnites acutus 

 (Cuttle-fish bones), Ammonites bifrons, A. heterophi/llus ; 

 Fishes — (enamelled) Eugnatkus, Dupedius, (Shm'k) Hyhodus 

 reticnlatus. Peculiar Crocodiles (Teleosniirus) . 



lace of the German Keuper.) 



'lace of the German (Upper) Bunter.) 



The earhest peinod known for Mammals {Microlestes) , which 

 are low ! Totally new Reptiles — Mastodonsaurus (large and 

 toad-Uke), Placodus, etc., replace earher kinds. New Fishes 

 SdUTicJith^Sy CJcTixtodos y Isdiyptcyiis^ Rpposr, most pnnm-ry" 

 kinds having died out ! Spec. Org. : — Shells — Myophoria, 

 Bakevellia socialis, AUorisma musculoides, Ceratites (link 

 between Carboniferous Goniatites and Jurassic Ammonites) ; 

 Crinoids — Lily-enerinite. 



Mstol Bone Co 



Shropshire Ca] 

 resden Rothlie 



In the British Isles there is a great Life-break between the Triassic and the Permian S3'stem ; the 

 former rarely contains any species of plants and animals characteriziug the Primary periods : pro- 

 bably, in other regions there may be a closer fossil agreement between the two Systems, caused by 

 their containing other coterminous Formations; or there may exist an intermediate System. 



nglomerate, and Doncaster Ked Sandstone 



careous Conglomerate, 

 jende. 



Life not abundant in European area ; possibly due to great 

 physico-geographical changes going on. Spec. Org. : — Eep- 

 tiles — PaloEosaurus, Thecodontosauru^ ; Fishes — (enamelled) 

 Palceoniscus comptus, Dorijopterus, Holacanthodus ; Crabs — 

 PalcEOcrangon (no Trilob'ites !) ; Shells — Camurophoria mul- 

 tiplicata, Strophalosia, Aulosteges umhonillatus, Schizodus, 

 Loxonoma Siredenhorgiana, Nautilus (true) ; Corals — (bryo- 

 zoic) Synocladia, Phyllopora (plated) Polyccelia. 



incashire and Durham Coal-measures. 



[rish Coal-measures. ? Inferior portion of South Welsh 

 Coal-measures. 



Devonshire Culm. 



iinburgh " Calciferous Sandstone." 



Singular Plants {Calamites, Lepidodendron, Sigillaria, Sphe- 

 nopteris, etc.) abound, their debris forming Coal beds ! 

 Eeptiles {Parahatrachus, Apateon) of lowest (fish-like) kinds 

 appear ! Spec. Org. : — Corals — Michelinia, lAthostrotion ; 

 Shells — Productus, Spirifer, Pldmondia, Antliracosia, Gonia- 

 tites ; Crinoids — Platycrinus, Woodocririns, Pentremiles ; 

 Crabs — Griffithides (Trilobites becoming rare), Bellinuriis ; 

 Fishes — Megalichthys, Bendrodus (rivalling Crocodiles in 

 size), PsammoduR, PalcB07iiscus. 



nocktopher (Kilkenny Plant-beds). 



Period of cuirassed ( Placoganoid) tishes {Pterickthys, Cocco- 

 steiis) ! Spec. Org. : — Corals— Cyatkopkyllum ccespitosum, 

 Favorites Goldfussi, Pleurodictyum ; Shells — Davidsonia, 

 Calceola, Stringocephalus,Megalodon, Clymenia ; Crinoidal 

 Echinoderms — Rexacriyius ; Trilobites — PronteusflabelUfer, 

 Phacopslatifrons; Fishes — (enamel-scaled or Lepidoganoid) 

 Osteolepis, Glyptolepis, Diplacanthus. Terrestrial Plants 

 exist — Cyclostigma, Aparoxylon, etc. 





Period of Graptolites (Zoophytes), straight-chambered Shells 

 (Orthoceros) , and Trilobites {Asaphus, Acidaspis, Phacops). 

 Singular helmeted (Placoganoid) Fishes {Pteraspis, Ce- 

 pkalaspis, etc.), first found in latest (Ludlow) Formation ! 

 Spec. Org. -.—Corals— Heliolites, Halysites; Shells— Pe/ito- 

 merus, Mtirchisonia, Maclurea, Lituites ; Peculiar Echino- 

 derms (Sea-urchin Group) — Sphceronites, Eucalyptocrinus, 

 Palceaster (ancient Star-fish). 





Plants (apparently Sea-weeds) and Animals rare ; latter more 

 abundant in America and Bohemia. Certain low forms, 

 viz. : (Zoophytes) Oldhamia (in Bray rocks), Dictyonema, 

 (Shell) Lingula Davisii, (Crabs of the Trilobite group) Pa- 

 Iceopyge, Conocephalus, Paradoxides, Oleiiui, etc., (? a Phyl- 

 lopod Crab) Symenocaria, (Annelids) Scolithus and Histio- 

 derma are Special Organisms of this Period. 





No traces of Life yet discovered in British rocks of this 

 Period, though sti'oug indications occur in America (Sterry 

 Hunt). 



Corrected for the ' Geologist.' 



1 



