68 Dr. W. C. Williamson on 



RACHIOPTERIS ROBUST A. Will. 

 A rare form, of which I have only two sections taken 

 from the same specimen. 



K.— p. 505, Fig. 23 A, C.N. 269-270. 



RA CHIOPTERIS INCEQ UA LIS. Will. 



Accidentally called R. irregularis in the text of Q. 



Q. — p. 206, Fig. 28. See C.N. 265b, 320 & 1814. 



RACHIOPTERIS CYLINDRICA. Will. 

 Transverse. 



I.— p. 350, Fig. 80, C.N. 179. 



p. 351, Fig. 87, C.N. 179; P. 351, Fig. 88, C.N. 179. 

 Longitudinal. 



p. 351, Fig. 86, C.N. 182, 



RA CHIOPTERIS ROTUNDA TA. 



Anachoroptis rotundata Corda. 



I. — p. 350, Fig. 79, C.N. 271. See also 272 and 273. 



RACHIOPTERIS GONIOCENTRA. Will. 

 C.N. 274 and 275. Not yet figured. 



RACHIOPTERIS DUPLEX. 



A very distinct form, only obtained hitherto from the 

 Burntisland or Petticur district. 



Vascular Axis. 

 Transverse. 



F.— p. 688 > Fig. 28, C.N. 223, -> a,a. Fig. 30, C.N. 237. Fig. 35, 

 a,a'. See C.N. 227. 



Longitudinal. 



p. 688, Fig. 29, C.N. 234. See also 232 and 244. 



Secondary Petioles. 



Transverse. 



See Figs. 35A to 35K. 

 P.— p. 693, Fig. 39, C.N. 240. Fig. 41. Figs. 35D, 35E. 

 Longitudinal. 



See C.N. 239, 242, and 243. Tracheids reticulated. 



