286 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [April 14, 



inches long, whereas those of Zam. obtusifolius, in the specimens I 

 have seen, scarcely reach the length of 1 inch ; while their absolute 

 breadth is the same in both. The veins are generally indistinct ; 

 where they can be clearly seen, they are from three to six in each 

 leaflet, parallel, and mostly equal ; but in some instances (perhaps 

 accidentally) two of them become much more strongly marked than 

 the rest, as in Brongniart's genus Nilssonia. 



The leaflets are not only much longer, narrower, and more grass- 

 like, than in the Zamites pectinatus of our Yorkshire oolite, but seem 

 also to have been of a softer and more pliant texture, many of them 

 being much bent and distorted. 



Of this plant there are several specimens, in a soft grey shale ; some 

 of them in the same slab with the beautiful Neuropteris already de- 

 scribed. 



12. SiGiLLARiA? or Lepidodendron ? 



A very obscure and indistinct impression ; the markings, as far as 

 they can be made out, much resembling those oi Sigillaria Menardi^. 

 They have some resemblance also to the JJlodendron minus of the 

 * Fossil Flora' ; and to a specimen from the Ohio coal-field, in Mr. 

 Lyell's collection, marked ^'Lepidodendron 3 C." 



13. 



Two specimens, apparently casts of small portions of a decorticated 

 stem, but extremely obscure and unsatisfactory. Their surface is 

 marked with small roundish-oval or nearly circular pits, placed about 

 yi^ inch apart, and arranged pretty regularly in spiral rows, like 

 the scars of Stigmaria. Each of these little pits is deepest near one 

 extremity of its axis, and is there marked with a very small scar, evi- 

 dently indicating the place where a bundle of vessels passed through. 

 A small portion of carbonized bark remains on one of the specimens, 

 but its surface retains no distinct markings. 



On the whole, the appearance of these fossils is a little like that 

 presented by the decorticated stems of some Lepidodendra ; but they 

 are too obscure to be determined with any precision. It is possible 

 that they may be decorticated portions of the same plant to which the 

 preceding No. belongs. 



14. Knorria? 



^' From Deep-run, Richmond." 



An impression of part of a stem or branch, about \ inch broad, 

 marked with (apparently) the scars of leaves, which are arranged 

 pretty closely, and with some regularity, in spiral lines. Each inser- 

 tion is marked by a small transverse depression or furrow, rather irre- 

 gular in direction and extent, from which another furrow generally 

 proceeds downwards for a short distance. These must have been 

 ridges or projections on the original surface of the stem which left 

 this impression. There is a slight excavation or depression of the 

 surface above each scar, and an elevation or puckering between them, 

 but nothing like distinct areolse. 



* Brongn. Veg. Foss. t. 158. f. 5. 



