ANlttVEESAEY ADDEESS OF THE PEESIDENT. 



225 



measures 32 genera and 50 species of Ganoidei occur, in the Middle 

 Coal-measures 5 genera and 6 species, in the Upper Coal-measures 

 6 genera and 8 species. The Placoidei are represented in the Lower 

 by 22 genera and 40 species, in the Middle by 10 genera and 14 

 species, and in the Upper by 6 genera and 8 species. Eegarding 

 the Coal-measure fishes as a whole, however, they stand in the Table 

 as Lower Coal-measures 52 genera and 112 species, Middle 14 

 genera and 20 species, and the Upper 12 genera and 14 species. 

 The numerical distribution for Britain and Belgium is — 



England 136 species. 



Scotland 152 „ 



Ireland 120 „ 



Belgium 50? „ 



The Carboniferous system is finely developed in Belgium. 37 of 

 the same genera occur in the American rocks, 10 being Ganoidei 

 and 27 Placoidei, the two orders there yielding 240 species. 



Amphibia. — Of the 4 orders in the class Amphibia, the Labyrin- 

 thodontia alone occur in the Carboniferous rocks. 26 genera and 

 33 species are known in Britain. Without exception they all 

 occur in one or the other of the divisions of the Coal-measures. 



Prof. Le Koninck, in his great work (' Ann. du Mus. Boy. d'Hist. 

 Nat. de Belg/ tome ii., Faune du Calc. Carb. de la Belg. pt. i.), has 

 described 29 genera and 44 species, all from the Carboniferous 

 Limestone. The fauna of the Coal-measures in Belgium is small 

 compared with that of Britain. 



The Lo wee-Coal- me asfee genera are Amphiccelosaurus, Amjphi- 

 saiims. Anthracerpeton, Brachyscelis, BatracMderpeton, Discospon- 

 dylus, Dolichosoma, Eipetocephalus, Icktkyerpeton, Kerateipeton, 

 Lepterpeton, Loxomma, Ophiderpeton. Labyrinthodontosaurus, Lepto- 

 gnathosaurus, JIacrosaurus, Megaloce-phalus, Orihosauruf;, Parabatra- 

 chus, Pholidogaster, Streptodontosaurus, and Urocordylus. 



The Middle- Co al-measube genera are only 3- — Anihraeosaurus, 

 Megalerpeton, and holiderjpeton. 



Loocomma and Pteroplax occur in both Lower and Upper Coal- 

 measures. 



"We are chiefly indebted to Professors Huxley and Miall for 

 elaborate researches into the structure and affinities of the extinct 

 order Labyrinthodontia, a group eminently characteristic of Carbo- 

 niferous time ; for, with the exception of Bhiyiosaurus from the Lias 

 and the Jurassic Brachyops, no remains of this order have hitherto 

 been discovered in rocks younger than the Trias. 



