Mineralogy and Geology. 1 1 



The author describes fifteen different forms of vegetable remains, of 

 which, however, only nine or ten are sufficiently well preserved to be 

 determined with any precision. Six are Ferns, of which three belong 

 to Pecopteris, one to Tceniopteris, one to Neuropleris, and the sixth 

 appears not to be referable to any genus hitherto described. The 

 Neuropteris, and one of the species of Pecopteris, are new. Oire of 

 the ferns is believed to be identical with Pecopteris whitbiensis, a 

 species characteristic of the oolites of the Yorkshire coast. There is 

 one species of Equisetum, — £. columnare — likewise characteristic of 

 the Yorkshire oolites; one, or perhaps two of Cahimites ; two (which 

 may possibly be mere varieties) of Zamites; the remainder are obscure 

 impressions of an equivocal nature, but of which one has a certain de- 

 gree of resemblance to a Stigmaria, and another to a Lcpidodendron. 



Five of these fossil plants had previously been determined and de- 

 scribed by Prof. W. B. Rogers, namely, Tceniopteris magnifotia, Pe- 

 copteris whitbiensis^ Equisetum columnare, Catamites arcnaceus, and 

 Zamites obtusifolius. Prof. Rogers described also a few other species, 

 which do not occur in the collection made by Mr. Lyell. 



From a comparison of these vegetable remains with those found in 

 European strata, of which the geological position is well known, it 

 roay be concluded with toterable certainty, that the Richmond coal- 

 field is of later date than the great carboniferous system, and that it 

 must be referred either to the lower part of the Jurassic, or the upper 

 part of the Triassic series, — more probably to the former. 



5. Remarks on a Boulder Mass of Native Copper from the southern 

 wore of Lake Superior; by Forrest Shepherd, (communicated by 

 request, to Prof. Silliman, for this Journal.) — The mass of native cop- 

 per in my possession, was discovered on the southern shore of Lake 

 Superior in July, 1845, by Tousant Piquette (an Indian of the Ojibwa 

 j«w) in or near latitude 47° 5' north, and longitude 88° 5' west. 

 1 l $ composed almost entirely of pure native copper with spots of 

 pure metallic silver upon its surface, together with a few water- worn 

 pebbles of syenite, sandstone, &c, strongly imbedded and fastened in 

 ! ts ^vities and sinuosities. Its length is about three feet and a half, 



Us breadth two feet and a half, thickness from seven to eight inches, 

 *nd its weight sixteen hundred and twenty-five pounds. As a speci- 



|d not well be better. One end is 



j 1 **^, its form and proportions cou 

 broader by a few inches than its oi 



pposite. One side discovers a slight 

 Natural rotundity and also a deep farrow cut obliquely into the solid 

 . met *l, while the other side, nearly flat, appears much worn and poL 

 ls hed in some places, whilst in other places it exhibits numerous grooves, 

 cratches and broad longitudinal furrows, showing evidently that the 

 J** has at some period been subject to great external violence. 

 vv hen found it was situated immediately upon the shore about three miles 

 northeast of Elm river, not more than two or thjree feet above the water, 

 *» only about six feet from the broad side of the lake. It was standing 

 ° n * smaller end, nearly in a perpendicular position, leaning Mi htly 

 ;pnst a much larger boulder of sienite. The lower end was buried m 

 ,he gravel of the shore about ten inches, and immediately underneath it 

 ^ found pebbles and small boulders of porphyritic greenstone, 

 J^te, sandstone, &e., and also an undecayed log of white cedar (ar- 

 bor ▼«*) on which it rested. Around it, both in the lake, and upon 



