282 Mr Arher, Notes on the Binney Collection 



the plant. The corresponding radial, and tangential longitudinal 

 sections, of the type, were easily distinguished by measurements, 

 in comparison with the transverse sections. 



The structure of Lyginodendron Oldharnium is now so well 

 known, that it would be difficult to add anything to our knowledge 

 of this plant. The opportunity has however been taken here to 

 figure some of Binney 's sections, and, at the same time, to point 

 out some of the more interesting features in the structure of these 

 important types. 



Lyginodendron Oldharnium (Binney). Type specimens. Wood- 

 wardian Museum, Cambridge. Binney Collection. Nos. 179 and 

 180 (T. S.), No. 181 (R. L. S.), and No. 182 (T. L. S.). 



Locality. Calcareous nodule in the Upper Foot Coal, 15 yds. 

 above the Gannister, at Moorside, near Oldham, Lancashire. 



1866. Dadoxylon Oldharnium. Binney, Proc. Lit. and Phil. 

 Soc. Manchester, 1866. 



1873. Dictyoxylon Oldharnium. Williamson, Part iv. Phil. 

 Trans., 1873. 



1873. Lyginodendron Oldharnium. Williamson, ibid. 



1890. Lyginodendron Oldharnium. Williamson, Part xvn. 

 Phil. Trans., 1890. 



1896. Lyginodendron Oldharnium. Williamson and Scott, 

 Part in. Phil. Trans., 1896. 



1899. Lyginopteris Oldhamiana. Potonie, " Lehrbuch der 

 Pflanzenpaleontologie," Berlin, p. 170. 



1900. Lyginopteris Oldhamia. Zeiller, "Elements de Paleo- 

 botanique." Text fig. 96, p. 127. 



1900. Lyginodendron Oldharnium. Scott, " Studies in Fossil 

 Botany." London, p. 308. 



Description of the Specimens. 



Slide 179. Text-figure I. 



A transverse section cut from the upper portion of the speci- 

 men, as the position of the leaf-traces, compared with that which 

 they occupy in Slide 180, shows. The stem has a diameter of 

 1'3 cm., and is almost circular. 



The medulla is 1*5 mm. in diameter, and the tissues are much 

 decomposed. Most of the thin-walled elements have disappeared, 

 forming a number of spaces, especially near the periphery of the 

 medulla, as is clearly seen in the figure. From the occurrence of 

 these spaces, Binney concluded that the medulla was similar to 

 that of Dadoxylon. It is hardly necessary to add that this 

 apparent separation between the medulla and the wood is entirely 

 due to bad preservation. Sclerotic nests with thick walls, and 

 darkly coloured contents, are numerous in this region. 



