XXXIII] CORDAITES 235 



ribs as unequal in prominence, the stronger ones being separated 

 by 1 3 finer ribs, while in the middle and upper portions the 

 ribs appear to be of equal size. Some of the finer ribs are due 

 to folding of the lamina and are not represented, as are the ribs 

 due to the presence of stereome-strands, by dark streaks in the 

 detached cuticle. 



Reference has already been made to the anatomical features 

 of leaves of this species described by Lignier 1 and other authors. 



Cordaites grandifolius Lesquereux. 



The leaves so named by Lesquereux 2 , from the Coal Measures 

 of Pennsylvania, are distinguished by the elongate cuneate 

 lamina, which reaches a length of 38 cm. with a narrow base and 

 a slightly rounded truncate distal end, 16 cm. broad, characterised 

 by a few broad and shallow crenulations. By contrast with some 

 American specimens in Dr Kidston's collection Lesquereux's 

 figures convey an imperfect idea of the size of the leaf. A large 

 leaf from the Coal Measures of Belgium described by Cambier 

 and Renier as a new species of Psygmophyllum, P. Delvali 3 , is 

 perhaps identical with the American type; the lamina of sub- 

 triangular form has approximately the same dimensions; the 

 veins are numerous and repeatedly forked. The leaf is much 

 longer than any known Psygmophyllum and the veins are much 

 more numerous than in P. magus Arb. 4 , the largest representative 

 of that genus. Palaeobotanists who have seen the type-specimen 

 inform me that they have no doubt as to the Cordaitean nature 

 of the Belgian specimens, which may be designated Cordaites 

 Delvali. It is, however, not impossible that Psygmophyllum and 

 Cordaites are allied genera : our knowledge of the former is limited 

 to unimportant characters. 



Cordaites (Dory-Cordaites) palmaeformis (Goeppert). 



This Permian type, originally described by Goeppert 5 "as 

 Noeggerathia palmaeformis, is characterised by numerous slender 

 veins : according to Weiss 6 there may be as many as 3 5 in 1 mm. 



1 Lignier (13 2 ). 2 Lesquereux (78) p. 318; (80) A. PL LXXVH. 



3 Cambier and Renier (10); Renier (10 2 ) PI. 118. 



4 See postea. 5 Goeppert (64) A. PL xxn. fig. 2. 

 fi Weiss, C. E. (72) p. 199. 



