174 FURTHER CONTRIBUTIONS TO THE FOSSIL FLORA. 
“There is some difficulty in assigning this species to the 
proper genus, in consequence of all the specimens I have 
examined being imbedded in a coarse sandstone, so that the 
venation, with the exception of a slight central depression 
indicative of a mid-rib, is nearly obliterated. With some 
care, however, in detaching the matrix from the pinnule, I 
have been able to trace what appears to be a slight radiation 
in the form of the secondary veins, resembling that generally 
found in Odonopteris (whence the specific name); this may 
prove to be deceptive, and other specimens may perhaps 
better elucidate this view.” 
“The general contour of this fern (Pl. vi. fig. 3) somewhat 
resembles a single pinna of Neuropteris conferta (Sternb.) ; but 
the pinnules are more oblong, and the terminal one accumi- 
nate; but it still more closely approaches in form a pinna of 
Odontopteris Permiensis, a fern described from the Permian 
system in the work on the Geology of Russia, by R. J. 
Murchison, Esq. 
“ Presuming, on the other hand, that it forms a portion of 
a flabellate frond, a pinna, of which a drawing only has been 
seen, bears considerable affinity as to its mode of furcation 
to the recent species of Gleichenia flabellata, and under this 
point of view might be associated with the genus Laccopteris 
(Presl.) should the venation prove to be the same.” 
Locality : Jerusalem basin. 
“A figure has also been given with more lanceolate shaped 
pinnular, which is probably only a variety of this species.” 
The above is a full account of the original description of 
Professor Morris’ type species, which was also accompanied 
by three illustrations (Pl. vi., fig. 2, 3, 4). 
Unfortunately in the shales of Jerusalem beds there exists 
a smaller dichotomous fern, which somewhat resembles the 
original type of Morris in the attachment of the pinnule. 
The pinne of the latter form Thinnfeldia obtusifolia (mihi), 
however, are invariably dichotomised ; the pinnules are devoid 
of any distinct mid-rib, and are altogether smaller and less 
coriaceous in texture. The veins arise from a common point 
at the base of the pinnule, from which they diverge to margin 
by repeated furcations. This form, moreover, occurs in the 
greatest profusion in the shales of the upper mesozoic beds 
in Tasmania, and invariably presents the same general 
characteristics in widely separated localities. Forms identical 
in all respects with Prof. Morris’ original type species are 
found rarely, and only occur in the coarse sandstones. 
It is more than probable therefore that the examples 
examined subsequently by Prof. M‘Coy, Messrs. Carruthers, 
Crepin, Etheridge, sen., Dr. Feistmantel, were identical 
with the smaller and more abundant dichotomous fern 
