No. 4.] DAWSON REPILLIAN IIEMAINS. 253 



trees in question, with lists of their Fossil remains. The most 



important part of the section is the following: : — 



fl. ins. 



Sandstone with erect Calamites and Stigmaria roots 6 6 



Argillaceous sandstone, Calamites, Stigmaria, and 



Alethoperis lonchitica. 1 6 



Gray shale with numerous fossil plants, and also 



Naiadites, Carbonia, and fish scales 2 4 



Black coaly shale, with similar fossils 1 1 



Goal with impressions of Sigillaria bark 6 



On the surface of the coal st<ind many erect Sigillarue, pene- 

 trating the beds above, and some of them nearly three feet in 

 <iiamet.er at the base and nine feet in height. In the lower part 

 of many of these erect trees there is a deposit of earthy matter, 

 blackened with carbon and vegetable remains, and richly stored 

 with bones of small reptiles, land snails, and millipedes. De- 

 tailed descriptions of the contents of these trees are given, and 

 it is shown that on decay of the woody axis and inner bark they 

 must liave constituted open cylindrical cavities, in which small 

 animals sheltered themselves, or into wliicli they fell and re- 

 mained imprisoned. These nntural traps must have remained 

 open for some time on a sub-aerial surface. 



In all twenty-five of the.se erect trees had been di.scovered and 

 extracted, and the productive portions of them preserved and 

 ■carefully examined. Of these fifteen had proved more or less 

 productive of animal remains. From one. no le.ss than twelve 

 reptilian skeletons had been obtained, in a few instances not 

 only the bones, but portions of cuticle, ornamented with horny 

 scales and spines, had been preserved. 



The Batrachains obtained were referred to twelve species in 

 all. Of these two were represented so imperfectly that they 

 could not be definitely characterised. The remaining ten were 

 referable to the two family groups of Micronduria and Labij- 

 rinfhodontid . 



The Mlcroanurid are characterised by somewhat narrow crania, 

 smooth cranial bones, simple or non-plaited teeth, well-developed 

 limbs and ribs, elongated biconcave vertebrae, bony scales and 

 plates on the abdomen, and horny scales, often ornate, on the 

 back and sides. They show no traces of gills. 



The species belonging to this group are referred to the genera 

 Hylonomus, Smihrpeton, Hyhrpeton^ and Fritschia. The cha- 

 racters of these genera and of the several species are given in 



