The leaves of _Cordaites (Noeggerathiopsis) Hislopi_ vary considerably in size, in some cases reaching a length of 80 cm. (fig. 471); the lamina tapers gradually from a short distance behind the obtuse apex to a relatively narrow base: in venation and form the leaves are very similar to those of _C. principalis_ and other European and North American species. The specimen from India represented in fig. 472 shows several spathulate leaves attached in a close spiral to a branch. As White[618] and Zalessky have shown, the stronger ribs are separated by less prominent striations indicating the presence of two sizes of hypodermal strands. The obvious resemblance between _Noeggerathiopsis Hislopi_ and species of _Cordaites_ has long been recognised and many authors have included Feistmantel’s genus in the Cordaitales[619]. Prof. Zeiller[620] preferred to retain the name _Noeggerathiopsis_ as a precautionary measure, chiefly on the ground that the stomata appeared to be less definitely arranged in rows and more scattered than in the European leaves of _Cordaites_, and because of the absence of interstitial veins. We have as yet little information as to the arrangement of the stomata, but in view of the irregularity in stomatal grouping in recent leaves this feature is, perhaps, of minor importance. The presence of interstitial ‘veins’ has now been established in Indian[621] and South American[622] leaves. In a paper published in 1908[623] the name _Cordaites_ was substituted for _Noeggerathiopsis_ and Zalessky’s recent work supports this step. The description by Zalessky of the ribbing in Goeppert’s species _Cordaites aequalis_ from Siberia shows how uncertain and variable a character the venation is even in different parts of the same leaf. _Cordaites Clerci_ Zalessky. This species (fig. 469, D) was instituted for some small lanceolate or spathulate leaves from the Petschora basin (Adzva River)[624] reaching a length of 6 cm. and a breadth of 1 cm. It is separated from _Cordaites aequalis_ on the ground that the veins are more numerous, as many as 44 in a breadth of 1 cm.