CYCADEAE, MEDULLOSEAE. 89 



The Otozamitae also have articulating pinnae which narrow at the 

 base and overlap and cover the axis. Each pinna has on that side of the 

 base which is towards the apex of the leaf a more or less strongly 

 developed projecting ear-like lobe, which has suggested the name of the 

 genus. The bases of all the pinnae when seen from the upper side and the 

 rhachis also, if the condition is strongly marked, are covered by the auricles 

 of the pinnae next below them ; the pinnules all lie like scales one on 

 another. The character is less prominent on the under side where the 

 rhachis is visible, because the latter partly hides the auricles. The appear- 

 ance therefore of the same leaf is quite different according to the position 

 in which it lies on the slab, and this must be considered in determining 

 these forms. The nervation also is essentially distinct from that of the 

 Zamitae, and corresponds with the nervation of Neuropteris and Cyclopteris 

 as defined by Mettenius for the Ferns. Numerous nerves run in curved 

 lines diverging and occasionally dividing dichotomously to the margin of 

 the leaf, so that the whole nerve-system is flabelliform in appearance. It 

 is true that these characters are not so striking to the eye in all the forms 

 of the type, as they are, for example, in Otozamites brevifolius, F. Braun \ 

 in O. Bunburyanus, Zigno 2 , and many others. As the auricles of the basal 

 extremities diminish in size, the fan-shaped nervation always becomes less 

 distinctly marked. Forms of this character, which are named Ptilophyllum, 

 Morris, are especially common in the Jurassic deposits of India, and are 

 further distinguished, according to O. Feistmantel 3 , by the decurrence of 

 the pinnules on the axis. The British Museum possesses beautiful~speci- 

 mens of this kind. Countless figures of them are to be found in Feist- 

 mantel's work just quoted, and in the Palaeontologia Indica 4 . In Schenk 5 , 

 as has been before said, the forms of this type are given among the Ferns, 

 partly on account of the structure of the epidermis, partly and chiefly 

 because the author became acquainted with a leaf found by Benecke 

 in Southern Tyrol and very like O. Bunburyanus, Zigno, in which the 

 pinnae showed on their under side a thickened seam-like margin. He 

 considers that this is the margin of the pinnule recurved as in Cheilanthes 

 and covering the sori ; but he has not been able to produce anything 

 decisive in support of this view. It may possibly be correct ; the difference 

 between the leaves of Ferns and Cycads are so minute that it is not incon- 

 ceivable that remains from both classes may have been placed with the 

 Otozamitae. In connection with this point the form named by Saporta G 

 Otozamites marginatus may also be compared. 



Of the flowers of Cycadeae only a few remains have been discovered, 

 and the greater number of these are in an indifferent state of pre- 



1 Schenk (3). 2 de Zigno (1;, f. 2. 3 Feistmantel, O. (1), I. ' Pal. Ind., ser. II, vol. i. 



5 Schenk (3). 6 de Saporta (4), vol. ii, t. 168. 



