AIR-BREATHERS OF THE COAL PERIOD. 89 



found scattered in every position, and those of different species 

 intermingled ; and that being often much more friable than the 

 matrix, much labour is required for their development ; while 

 after all has been done, the result is a congeries of fragments like 

 that presented by Plate III. The two specimens which displayed the 

 largest number of bones in juxtaposition, are one of Dendrerpeton 

 Acadianum, and one of Hylonomus Lyelli, both presented by me to 

 the geological Society of London, and now in its collection ; but of 

 which I shall endeavour to obtaiu accurate representations for 

 this memoir. 



In order more fully to illustrate the mode of occurence of these 

 remains, I quote the following notice of my last explorations in 

 the bed containing them, from the Journal of the Geological So- 

 ciety of London, for 1861 : 



" In the bed which has hitherto alone afforded reptilian re- 

 mains in its erect trees, two additional examples of these were 

 exposed. One was on the beach, and in part removed by the sea. 

 The other was in the cliff, but so far disengaged that a miner 

 succeeded in bringing it down for me. In the Srst, comparatively 

 little was found. It afforded only a few shells of Pupa vetusia, 

 and scattered bones of a full-grown individual of Dendrerpeton 

 Acadianum. 



" The second tree was more richly stored ; and, being in situ, 

 was very instructive as to the mode of occurence of the remains. 

 Like all the other trees in which reptilian bones have been found, 

 it sprang immediately from the surface of the six-inch coal in 

 Group XV. of my section* ; which is also Coal No. 15 of Sir W. 

 E. Logan's sectionf . Its diameter at the base was two feet, and its 

 height six feet, above which, however, an appearance of additional 

 height was given by the usual funnel-shaped sinking of the over- 

 lying beds toward the cavity of the trunk. The bark is well pre- 

 served in the state of bituminous coal, and presents externally a 

 longitudinally wrinkled surface, without ribs or leaf-scars; but 

 within, on the ' ligneous ' surface, or that of the inner bark, there 

 are broad flat ribs, and transversely elongated scars. The ap- 

 pearances are precisely those which might be expected on an old 

 trunk of my Sigillaria Brownii ; to which species this tree may 

 have very well belonged.^ 



* Quart. Journ. Geol. Soc. Vol. ix. p. 58, and Vol. x. p. 20. 

 t Reports of Geol. Survey of Canada, 1845. 

 X Quart. Journ. Geol. Soc. Vol. XTii.p. 523. 



