92 
DESCRIPTION OE SPECIES. 
CRYPTOGAMS. 
Filices. 
Pteris Torresii, sp. nov. 
Plate YIII, Fig. 1. 
Sp. Char. — P. fronde pinnata, pinnis pinnatifidis, lobis suboppositis, 
inaequalibus, ovalibus vel lanceolatis, acutis serrulatis ; nervatione Aletliop- 
teridis ; nervo primario tenui ; neryis sccondariis angulis acutis exeuntibus, 
furcatis ramis abbreviatis. 
Ohs . — Only a small fragment of tliis fern (PI. YIII, tig. 1), lias 
been collected. Fortunately this well-preserved specimen permits one to 
establish a scries of characters which suffice for the correctness of its deter- 
pinnate. The frond, of more membranaceous than coriaceous texture is 
pinnate; the pinnae are pinnately divided or equally lobed ; the lobes are 
13-14 millimeters long and 5-G centimeters broad, nearly opposite, more or 
less oblique to the racliis, ovate or lanceolate, and acute-serrulate. The 
nervation, showing the Alethopteris- type, consists of a tender primary nerve, 
which turns off at a more or less acute angle, and of 7-8 very fine secondary 
nerves on each side, which pass under acute angles. The primary nerve is 
still distinctly to be seen on the apex ; the secondary nerves are catadromic, 
and all separated, forking once with short branches, terminating the teeth. 
Fructification is not visible. 
These characters and the nature of the described fossil lead perceptibly 
to the genus JPteris. Through a more general comparison with similar ferns, 
we may even discover species of Aspidium, Cyatliea, and Alsophila , which 
