XXX] NEUROPTERIS 113 



preservation the leaflets resemble Goeppert's Permian species 

 Dictyothalamus Schrollianus 1 . 



Alethopteris. Linopteris. 



No specimens of Alethopteris fronds have so far been describee! 

 that afford any information as to the nature of the microsporangia, 

 and we have no means of knowing whether they were borne on 

 naked pedicels as in Neuropteris heterophylla, or on modified 

 pinnules as in N. gigantea. 



Zeiller in 1888 2 described some fertile pinnules of Dictyopteris 

 Schutzii Roem. from Commentry bearing two rows of long 

 sporangia: he subsequently transferred this species to the genus 

 Linopteris 3 and expressed the opinion that the sporangia occur 

 singly and not in groups as he originally believed. Zeiller compares 

 the fertile pinnules with the type Crossotheca. Bertrand 4 , as 

 the result of examining similar specimens, has suggested that 

 the fringe of pendulous bodies regarded by Zeiller as sporangia 

 may be tooth-like lobes of modified pinnules which served to 

 protect microsporangia borne on the lower surface of the lamina. 

 The nature of the impressions is not clear, though there is little 

 doubt that they are microsporophylls. The fertile pinnae of 

 Linopteris obliqua (Bunb.) described by Carpentier 5 and Bertrand 6 

 closely resemble the microspore-b earing organs which have been 

 referred to Neuropteris gigantea; they have the characters of 

 Potoniea and consist of oval laminae similar to the sterile pinnules 

 but about half their size: the lamina was attached excentrically 

 to a slender stalk (fig. 421, C, E) and traversed by numerous 

 occasionally anastomosing veins. No actual microsporangia have 

 been discovered in organic connexion with the lamina. 



b. Megasporangia. 

 Neuropteris. 



Kidston's discovery of undoubted seeds attached to pinnae 

 of Neuropteris 1 marked an important step in our more exact 



See page 127. 2 Renault and Zeiller (88) A. p. 273, PL xxxi. figs. 2, 4. 

 Zeiller (90) B. PL xi. fig. 9 ; (OO) 2 B. p. 108, fig. 83. See Vol. n. p. 572. 

 Bertrand, P. (13) p. 132, PL vi. fig. 7. 

 Carpentier (13) p. 375, PL vra. fig. 1. 

 Bertrand, P. (13) p. 135, pi. vi. figs. 2 4. 

 Kidston (04); (04 2 ); (14) p. 107, fig. 5. 



s. in 8 



