The Fossil Plants of the Coal Measures, 65 



Inner Cortex. 

 Radial. 



N.— p. 291, Fig. 9D, C.N. 1622. 



Outer Cortex. 

 Transverse. 



N. — p. 290, 291, Fig. 6r, C.N. 1303. Fig ir, C.N. 1302. 

 Radial. 



N. — p. 292, Fig. 11, CN. 1304. 



Medullary Cylinder. 



Transverse. 



P.— p. 156, Fig. 2b, C.N. 1833 ; p. 156, Fig. ibb~.* 



Aerial Rootlet Bundles. 



Transverse. 



P. — p. 157, Figs 1 and 3. Seen in most of the transverse sections. 



Epidermal Hairs. 



P. — p. 158 and the Longitudinal section, C.N. 1857. 



Tracheids of Medullary Cylinder. 

 All barred. See 1842 x and 1843 x • 



Cortex. 



Mixture of Parenchyma, C.N. 1840, and Prosenchyma, C.N. 1841. 



ZYGOPTERIS.— Petioles only preserved. 



ZYGOPTERIS CORD A. 



During the last twenty years numerous organisms have 

 been described under the name of Zygopteris. Most of 

 these have been fern-like petioles. In 1889, Professor 

 Stenzel, of Breslau, published a Memoir " On the Stem of a 

 Carboniferous Plant," to which he gave the name of Zygop- 

 teris scandens, but which he placed in a secondary division 

 of the Zygopteroid group (A nkyopteris). I had previously (in 

 1 888), figured one under my type-name oiRachiopteris Grayiu 

 Dr. Stenzel having sent me a copy of his Memoirs, I arrived 

 at the conclusion that our two plants were identical. In 

 order to obtain his opinion on the matter, I sent him one of 

 my sections of Rachiopteris Grayii for comparison with his 



* There is still some obscurity in the relations of ib' to 2b'. Is the latter a modified con- 

 dition of the former, or is it identical with the axil-sprosse of Stenzel, Fig. 3b, the Zygop- 

 teriod petiole being wanting ? 



