TRANSACTIONS OF THE SECTIONS. 59 



amined we find that many are goncrically, and all are specifically distinct from both ; 

 bi-'side.s this we discover that a new group of organisms of a dillereut and higher 

 type of structure are now introduced for the first time — namely, those remarkable 

 forms of the ichthyic class the fishes of the Old Red Sandstone, and whose singular 

 forms with their bony armour and osseous scales remind us of the remarkable 

 fishes Lepidosteus and Poli/pterus from North-American, African, and Australian 

 rivers of our time. The hieroglyphics, therefore, engraven on the strata of the 

 second age are visibly diiferent Irom those on the first. 



The Carboniferniis" succeeds the Devonian ; and here we find a marvellous deve- 

 lopment of the life of this age preserved in the cases of this Institution. Pray 

 study attentively the fine specimens of Anthozoa here exhibited, all derived from 

 the upper beds of the Carboniferous Limestone at the gorge of the Avon, and show- 

 ing very clearly that this portion of tlie section was formed in a tropical sea, and 

 that the limestone is the product of the living energies of those Polyps, sections of 

 whose skeletons lie there before you. Of the fiimily FAVOsixtDiE we see Favusitcs, 

 Alveolites, Syrinr/opora Michelima ; and of the family Cyathophyllid^ we have 

 Ciinthophyllimi, Lithosirotion, Lonsdnlia, &c. Many of the beds of limestone are 

 almost entirely composed of the o.ssicula of Crinoids ; and we see the stems, arms, 

 and calyces of these sea-lilies strewed in abundance in the rocks, such as Actino- 

 crinus, Poferiocrinns, Platycrinus, Cyatliucrinus, Pentremites, &c., with the remark- 

 able ancient Sea-urchin Palcecliinus associated with them. The MoUusca were 

 chiefly represented by the Brachiopoda, which were very common in the Carboni- 

 ferous age, as you may see in the large slabs containing Orthis, Spirifcra, vrad. Pro- 

 thtctus in great profusion. The Lamelhbranchiata were represented by Cardiomorpha 

 and Conocardium, and the Gasteropoda by Euumphalus, Plenrotomaria, and Natica, 

 and the Cephalopoda by Goniatites, Orthoceras, kc. The Trilobites, which formed 

 so remarkable a feature in the fauna of the Silurian sea, are here represented 

 by a few specimens of Phillipsia, a dwarfed genus of this family. The tine 

 collection of teeth and spines of large fishes from the Carboniferous Limestone 

 enables us to compare the forms of this age with those of the Devonian already 

 described, and shows at a glance that the ichthyic types in the seas of these two 

 periods were entirely distinct, and both evidently adapted to conditions of existence 

 widely difterent. 



The life of the Carboniferous Limestone proves that it was a great marine forma- 

 tion accumulated during a long lapse of time out of the exuvne and sediments of 

 many generations of Mollusca, Echinodermata, and Actiuozoa, the reef-building 

 corals having contributed largely to the thickness of the Coral-beds, and the wasted 

 reefs of former generations having been used up again and again in the formation 

 of the Oolitic beds which succeeded the reef-building periods. 

 rv The Coal Measures present a remarkable contrast to the Coral sea of the Carboni- 

 ferous era. The Ferns (Styillana, Lepidodendra) and other arborescent Acrogens of 

 the Coal-seams grew and flourished in low islands ; and their remains were accu- 

 mulated under conditions very difterent from those in which the thick-bedded lime- 

 stones of the Avon section were formed. Good typical examples of the vegetation 

 of this remarkable time in the world's history are well preseiTed in the large 

 collection, filling several cases ; these specimens are aU very fine, and require, and 

 I am sure will have, a careful examination. 



With the close of Palaeozoic time there appears to have been a great break in 

 the stratigraphical sequence of the fossiliferous rocks ; mighty changes then took 

 place. Volcanic agency was intense and active, flexing, contorting, and upheaving 

 the older beds. These displacements in our area were post-carboniferous and 



fire-triassic, and are well exemplified in the unconformable position of the Dolomitic 

 Conglomerate and New Red Sandstone of the Bristol district. 



The dolomitic conglomerate contains the bones of Dinosaurian reptiles clis- 

 covered in Durdham Down, and preserved in this Museum ; they were described 

 by Dr. Riley and Mr. Stuchbury in 1836*, and were then the oldest Dinosauria 

 in Britain. Since that date the Triassic sandstones of Cheshire, Scotland, and 

 North America have been found to contain the foot-imprints of Cheirotheria, 

 and the same formation near Warwick the bones and teeth of remai'kable reptiles 



* Trans. Geol. Soo. 2ud series, vol. v. n. 349 (1840). 



0* 



