421 



and parts of different species of pines, of tithymals, cereuses, 

 of large reeds, and of some arborescent plants. His account is 

 accompanied by engravings, the descriptions of which are neces- 

 sarily very short. His first figure is of an impression of a plant 

 with rhomboidal work on it, with which three long narrow leaves 

 were found, which appeared to belong to it. This specimen was 

 from Oswestry, in Shropshire ; a similar figure is given by Volck- 

 man, in his Silesia Subterranea, Tab. XXII. Fig. 2. ; and it seems 

 to resemble that described in Dr. Woodward's Catalogue, B. 107, 

 q. 22. q. 32. p. 106. The second and fourth seem to be of the reed 

 kind, having knobs placed in rows on their surface, like the vesicles 

 of some species of the rushes. This specimen seems to have been 

 similar to one described by Dr. Woodward, B. a. 1. p. 9- The third 

 impression he supposes to have derived its figure from some plant 

 of the fir kind. The fifth specimen is from Mostyn colliery, Flint- 

 shire : its surface, when attentively viewed, exhibits a reticular im- 

 pression of mesh-work, or rhomboidal hollows; the sides of the 

 rhombs, or the net-work, being raised in relief. In Plate I. Fig. 6. 

 you will find the representation of a similar specimen from France ; 

 and serves as an instance of the peculiarity of surface these im- 

 pressions frequently possess. The appearance here so varying, with 

 the change of light, as hardly to admit a fair representation of the 

 proteal surface ; the artist, with every exertion, was not able to 

 succeed to his wish in this respect ; since although in some points 

 of view the rhomboidal form would appear, in most others the 

 transition into somewhat of an oval appearance would be dis- 

 coverable. In the centre of these projecting bodies, small holes are 

 observable, being such as might be expected for the insertion of 

 seta3, or of setaceous leaves. In the sixth of Mr. Da Costa's spe- 

 cimens, studs, apparently also for the insertion of setae, are regu- 



* Philosophical Transactions, Vol. L. Parti, p. 228. 



