Page:The Journal of geology (IA journalofgeology21894univers).pdf/274

than most of those of that plant, and indicate that those on this plant, lower down, are somewhat larger than those of G. Zippei. The form is also something like Aspidium heterophyllum, of the Potomac, but seems to be smaller and more delicate. It may however be the same.

"3. The most common fossils are fragments of detached leaflets and one entire leaflet, of a plant which is strikingly like a Neuropteris of the coal measures (N. flexuosa). I am pretty sure, however, that it is a Glossozamites, a form of cycad that has leaflets which, in form and nervation, closely resemble Neuropteris. This, if a Glossozamites, has leaflets proportionately broader and shorter than any known to me, and it is probably new.

"4. There are a number of imprints left by organisms which in shape, dimensions, etc., would agree with fragments of the leaves of Pinus, or of Leptostrobus, but as nothing of the nervation is shown, it is not possible to say which they are. Some of the imprints are too deep and open, apparently, to have been formed by leaves. They seem to have been straight, slender stems.

"It will be seen from this account that the plants, so far as one can judge from such imperfect material, indicate a lower Cretaceous and Neocomian age, with rather more resemblance to the Kome than Potomac phase or grouping, but it is by no means certain that the Potomac grouping is not nearest to that here shown."

Thin sections of some of the silicified wood have been made and microscopically studied by Professor F. H. Knowlton. He reports the results as follows:

"The structure of this wood is very finely preserved, and a glance suffices to show that it possesses the Araucarian type and represents, with little question, an undescribed species of the genus Araucarioxylon. The wood-cells are provided with two rows of alternating hexagonal pores on the radial walls, which nearly, or in some cases, quite cover the walls. The medullary rays are composed of a single layer of thin, short cells, each of which is covered on the radial side with numerous fine dots or punctations. The rays are from one to bout twenty cells high, the average number being perhaps eight or ten. A