50 Transactions of the 



III. — On the Structure of the Stems of the Arborescent Lyco^o- 



diaceas of the Coal-measures. By W. Carbuthers, F.li.S. 



IV. On a Leaf-hearing Branch of a Species of Lepidodendron. 



{Read before the Royal Mickoscofical Society, Jan. 3, 1B72.) 



Plates VII. and VIII. 



The beautiful series of specimens illustrating the structure of this 

 Lepidodendron have been recently obtained for the British Museum 

 from the valuable collection of Mr. John Butterworth, of Shaw, near 

 Oldham. Like my friend Professor Williamson, I have also to 

 express my great obligations to Mr. Butterworth for the singularly 

 instructive specimens which he has submitted to my examination. 

 Living as he does on the spot where the calcareous concretions, 

 which have supplied such valuable materials to recent workers, 

 occur, imbued with a love for the study of these ancient vegetable 

 forms, and having an extensive and accurate knowledge of their 

 structure, and a quick eye for the parts in their structure which are 

 yet only obscurely known, Mr. Butterworth makes sections with his 

 own hands of carefully- selected materials, in a manner which renders 

 them highly instructive, and greatly facilitates the labour of inter- 

 pretation and description. The truth of these observations will be 

 apparent by the series of drawings accompanying this paper, made 

 by Mr. Hollick from four slides representing transverse and longi- 

 tudinal sections of the stem and transverse sections of the leaves 

 close to and at a little distance from the stem. 



Of the numerous figures that have been given by Witham, 



EXPLANATION OF PLATES. 

 Plate VII. 



Fig. 1 .^-Transverse section of the branch of a Lepidodcndron — natural size, 



„ 2. — Longitudinal section of the same — natural size. 



„ 3. — The lower portion of Fig. 1 enlarged 8 diameters, a. the vascular axis 

 with the processes representing the leaf bundles not yet liberated from 

 the axis, and surrounded by the free leaf bundles. 6. the space occu- 

 pied by delicate cellular tissue, now filled with carbonate of lime. 

 c. the epidermal tissues, with openings through which have passed the 

 leaf bundles, d. the bases of the leaves, showing also the single vas- 

 cular bundles passing to them. 



„ 4. — Portion of Fig. 2, enlarged 8 diameters. The letters indicate the same 

 parts as are represented in Fig. 3. e is the leaf base, showing the line 

 of articulation. 



Plate VIII. 

 Fig. 1. — The bases of four leaves cut through near their connection with the stem. 



„ 2. — The bases of the leaves at a greater distance from the stem. 



„ 3. — A single leaf (a. from Fig. 1), magnified 18 diameters, showing the 

 single vascular bundles at the lower part. 



„ 4.— A single leaf (a. from Fig. 2), magnified 18 diameters, showing the 

 leaf bundle of Fig. 3 split into two distinct bundles. 



