COAL ROCKS OP EASTERN VIRGINIA. 309 



the frond, and rounded oft' at the end. Midrib thick, marked on 

 the superior side by a somewhat deep groove and numerous 

 parallel lines ; nervures perpendicular to midrib ; simple, or very 

 rarely bifurcated ; parallel, distinctly prominent, and numbering, 

 in the large frond, from fifty to sixty to an inch. 



The genus Tccniopteris, entirely unknown in the carboniferous 

 formation, first makes its appearance in the new red sandstone, 

 and still later, forms, in the lias and oolite, an important and appa- 

 rently characteristic group. The species most nearly allied to our 

 fossil, namely, T. vittata, T. scitaminea, T. major, and T. latifoUa, 

 appear to be peculiar to the lower part of the oolite and the lias, 

 either one or all of them being found in this geological position 

 at Hoer, Neuewelt, Whitby, Scarborough, Stonesfield, and other 

 localities. 



Speaking of the vittata, Brongniart says : " This fern is one of 

 the most common in the Jura formations, and may be regarded as 

 one of the characteristic plants of our third period of vegetation. 

 From a citation of localities, it appears that it has already been 

 found in widely distant places, and that it is especially abundant 

 in the Oolite marls of the coast of Yorkshire." 



Pecopteris Whitbiensis. Brongniart. 



Although fossils of the fern tribe are of very rare occurrence in 

 the strata of which I am now treating, I have been fortunate 

 enough to procure several specimens in a good state of preser- 

 vation. These I find to be referable to three species, closely 

 resembling, if not identical with species found*in the lower 

 part of the Oolite in Europe. The fossil referred to under the 

 present head, corresponds so well with Brongniart's figures and 

 description of P. Whitbiensis, that, notwithstanding a slight dis- 

 agreement in one or two minor points, I cannot but regard it as 

 of the same species. 



The leaf is bi-pinnate, the rachis thick and smooth, the pinnae 

 oblique, opposite, straight, much prolonged, and tapering towards 

 the apex. The pinnules are contiguous, but not confluent ; pro- 

 tracted at the upper part of the base, contracted at the lower ; 

 they are arcuate-acute, but less so than in Brongniart's figure of 



