260 TRANSACTIONS OF THE 



DESCRIPTION OF A NEW FOSSIL PLANT FROM PENNSYLVANIA 

 OF THE GENUS EQUISETUM. By R. Harlan, M.D., &c. 



Equisetum stellifolium. pi. 14, fig. 4. 



E. Caule erecto, simplici, Isevi, cylindricoj diametro 

 1-8 poll., subsequali; ramulis 10, 12, ad articulationes 

 caulis vcrticillitis, stellitbrmibus ; articulis vix distinc- 

 tis, versus basim distantibus, superne approximatis ; m- 

 ginis indistinctis. 



Geological position — Coal measures, bituminous shale. 



Loc. — Pennsylvania, Schuylkill anthracite coal mines. 

 Cabinet of the Geological Society of Pennsylvania. 



This beautiful and delicate little plant has left its 

 image in a strong and vivid impression on a piece of 

 densely foliated shale, 5 by 3 inches in size, and rather 

 less than half an inch in thickness, displaying exceedingly 

 minute and numerous particles of mica intimately incor- 

 porated. 



So beautiful and symmetrical in appearance is this im- 

 pression, that I conceived on first view the Idea of an 

 artificial production, but its true character is easily re- 

 cognisable by observing similar impressions in the diffe- 

 rent laminae throughout the specimen, some of which I 

 have uncovered from the vicinity of both surfaces. 



The principal and most perfect stalk of these impres- 

 sions is about three inches in length, destitute of striae, 

 strongly but unequally divided into five separate but 

 continuous pieces, by an equal number of knots or arti- 

 culations, the pieces diminishing in length in ascending, 

 the first being seven-eighths of an inch, the second five- 

 and-a-half-eighths, the third four-and-a-half-eighths, the 

 fourth four- eighths, &c. The stalk, originally cylin- 



