300 Sternhergice. 



were also comparatively rare ; and I was unable to understaucf 

 how casts of the pith of conifers could assume the appearance of 

 the naked or thinly coated Sternbergiae, Additional specimens 

 affording well-preserved coniferous tissue, have removed these 

 doubts, and in connection with others in a less perfect state of pre- 

 servation, have enabled me more fully to comprehend the homo- 

 logies of this curious structure, and the manner in which 

 specimens of it have been preserved independently of the wood. 



My most perfect specimen is one from the coal field of Pictou, 

 (Fig. 1.) It is cylindrical but somewhat flattened, being one inch 

 two tenths in its least diameter, and one inch and seven tenths 

 in its greatest. The diaphragms or transverse partitions appear 

 to have been continuous, though now somewhat broken. They 

 are rather less than one tenth of an inch apart, and are more 

 regular than is usual in these fossils. The outer surface 

 of the pith, except where covered by the remains of the wood, is 

 marked hy strong wrinkles, corresponding to the diaphragms. 

 The little transverse ridges are in joart coated with a smooth- 

 tissue similar to that of the diaphragms, and of nearly the same' 

 thickness. 



When traced around the circumference or toward the centre, the' 

 partitions sometimes coalesce and become double, and there is a ten- 

 dency to the alternation of wider and narrower wrinkles on the sur- 

 face. In these characters and in its general external aspect, the spe- 

 cimen perfectly resembles many of the ordinary naked Sternbergiae' 



On microscopic examination the partitions are found to consist 

 of condensed pith, which, from the compression of the cells, must 

 have been of a fiim bark-like texture in the recent plant, (Fig. 2 

 and 3.) The wood attached to the surface, which consists of 

 merely a few small splinters, is distinctly coniferous, with two and 

 three rows of discs on the cell walls, (Fig. 4.) It is not distin- 

 guishable from that of Pinites, {Dadoxyion,) Brandlingi^ of 

 Witham, or from that of the specimens figured by Professor Wil- 

 liamson. The wood and transverse partitions are perfectly silici- 

 fied, and of a dark brown colour. The partitions are coated with 

 small colourless crystals of quartz and a little iron pyrites, and 

 the remaining spaces are filled with crystalline laminae of sulphate 

 of barytes. 



Unfortunately this fine specimen does not possess enough 

 of its woody tissue to show th« dimensions or age of the trunk or 

 branch which contained this enormous pith. It proves, however. 



