Mr Arber, Notes on the Binney Collection, etc. 281 



Notes on the Binney Collection of Coal-Measure Plants. Part III. 

 The Type- Specimens of Lyginodendron Oldhamium (Binney). By 

 E. A. Newell Arber, B.A., Trinity College, University Demon- 

 strator in Paleobotany. 



[Eeceived 25 November 1901.] 



In a paper published in the Proceedings of the Manchester 

 Literary and Philosophical Society for 1866, the late E. W. 

 Binney gave a brief account of the structure of a new fossil-plant, 

 which he named Dadoxylon Oldhamium. Binney's description 

 will be found quoted at some length by Williamson l , in his fourth 

 memoir on fossil plants. In the same memoir, Williamson gives 

 reasons for transferring Binney's plant to the genus Lyginodendron. 

 The structure of this plant has been worked out in great detail by 

 Williamson' 2 , and also by Williamson and Scott 3 ; and to these 

 authors we are indebted for a singularly complete knowledge 

 of one of the most important among Palfeobotanical types. 



Binney did not figure any of his sections of this plant. His col- 

 lection was presented to the Woodwardian Museum, Cambridge, in 

 1892. Unfortunately very few of the sections have any record as to 

 their nature, or origin, and the often difficult task of identifying type, 

 and figured specimens, has gone on ever since. The collection 

 contains four sections, two transverse and two longitudinal, which 

 are undoubtedly those named by Binney Dadoxylon Oldhamium ; 

 they are in fact sections of the type specimen (apparently not now 

 in the collection) of the plant generally known as Lyginodendron 

 Oldhamium (Binney), or by some authors as Lyginopteris Oldhamia. 

 The two transverse sections 4 , cut from the same specimen at different 

 heights, agree exactly with Binney's description. They are, as he 

 states, f inch in diameter, and show an apparent line of separation 

 between the medullary region and the wood. There are only 

 three other transverse sections in the collection, of which one does 

 not show all the tissues described by Binney, and the other two are 

 much larger (1 inch or more in diameter), and do not show "the 

 intervening spaces vertically" between the medulla and the wood. 

 These three specimens were probably acquired later than the type, 

 for Binney says that, at that time, he had only one specimen of 



1 Williamson, Phil. Trans, p. 377, 1873. 



2 Williamson, ibid, and Part xvn. p. 89, 1890. 



a Williamson and Scott, Part in. Phil. Trans, p. 703, 1896. 

 4 These were recently thinned, and covered, by Mr Lomax. 



VOL. XI. PT. IV. 21 



