28 
venation of the fronds is made available* That the majority 
of these were herbaceous is beyond doubt, but it is highly 
probable that some of the larger examples, as the genera 
Pecopteris and Neuropteris, constituted the frondose foliage 
of such stems as Sigillaria, Favularia, &c. In the first 
place, for the many hundreds of specimens of these genera 
found in every coal formation in Europe and America, 
which we know to have been stems, no foliage or flowers 
have ever been detected attached or detached, which 
appeared to have belonged to them ; but, on the contrary, 
we do find, and not uncommonly, the fronds of ferns, or 
at least portions, whose magnitude would justify our sup- 
position that they had originally formed the pendant summit 
of some of those lofty stems associated with them in the 
same bed of shale. In the Lancashire coal field Mr. 
Binney finds the Neuropteris heterophylla and Pecopteris 
lonchitica and nervosa, with Sigillaria; the same species occur 
in the Newcastle and Durham strata, according to Mr. 
* The subjoined characters of six genera which most frequently occur, will 
serve to explain the different modes of venation, &c, upon which the distinc- 
tions are founded : — 
Pecopteris embraces those species whose leaves are once, twice, or thrice 
pinnated, the leaflets adhering by the whole base, or by the centre only, with 
a midrib running from the base to the extremity, veins proceeding from it at 
nearly right angles. 
Neuropteris, leaves similar to the last, but more commonly somewhat ovate, 
attached by the centre only ; the midrib does not reach the apex of the leaflets, 
but divides off right and left into veins, and gradually disappears. 
Odontopterls, leaves like the last, but the leaflets adhere to the stalk by their 
whole base ; no midrib ; and the veins spring side by side at once from the 
base of the leaflet, passing onwards to the extremity. 
Sphenopteris, leaves twice or thrice pinnatifid ; the leaflets narrowest at the 
base, and wedge-shaped ; the veins generally arranged as if radiating from the 
base. 
Cyclopteris, leaves simple, either undivided or only lobed at the margin, more 
or less orbicular ; midrib none ; veins numerous, radiating from the base and 
forked. 
Schizopteris, like the last, except that the leaf is deeply divided into numerous 
unequal segments, which are usually lobed and taper-pointed. 
