1308 ADDITIONS TO THE FOSSIL FLORA OF EASTERN AUSTRALIA, 
wide. The pinnse are certainly narrower than D. gleichenoides,. 
V)ut as this point may entirely depend on the position occupied by 
the specimen in the frond, it cannot be taken as a point of much 
impoi'tance. 
As no fructification has been seen, it would perhaps be more 
advisable to place the Croydon fossils, “ characterized by the 
slenderness of the whole leaf, and by the delicate linear form of 
the pinme” (Feistmantel), in Ghichanitps, as Oldham and Morris 
have done with their s[)ecies ; although, be it noted, they refer to 
the general resemblance of the latter to Didymoso rus. On the 
other hand, so close a resemblance can hardly have existed, 
w'ithout some corresponding affinity in the productive state, and I 
shall therefore venture to place GleichenHes yleichenoides in Didy- 
mnsorus, and provisionally refer the Australian form to it. 
The general relations of this peculiar fern have been ably 
discussed by the late Messrs. Oldham and Morris ; but in their 
description they state the pinnae are alternate. Their figures, 
however, show as much variacion from alternate to opposite as do 
our specimens. At the same time the pinnae are apparently closer 
in the Indian fossils. 
The small ovately-pointed pinnules, entirely decurrent as they 
are, give to the pinnae a fret-saw-like appearance, and are evidently 
a very characteristic feature of the fern. In consequence of the 
gritty nature of the matrix the venation is obscure, but Oldham 
and Morris .say generally — “ The nervation of the pinnules, is 
very indistinct, but seems to consist of a small flexuous mid-rib 
Itecoming nearly obsolete at the end of the pinnules, and from 
which secondary veins pa.ss off obliquely at irregular intervals.”* 
/ 
^IDYMOSORUS (?) GLEICHENOIDES, Old. and Moi’., var. 
^ (PL__x^viii. fig. 3.) 
Pecopteris ( Gleichenites) liiiearis, O. and M., Mem. Geol. Survey 
India, II. p. 324. 
* hoc. cit. , p. 46. 
i 
