116 WEICHSELTIA. 
1883. Lonchopteris Mantelli, Renault, Cours bot. foss. vol. iii. p. 167. 
1888. Weichselia Ludoviee, Schulze, Flor. subhercyn. Kreid. p. 14. 
1889. Lonchopteris Mantelli, Bristow, Geol. I. Wight, p. 258. 
1890. Weichselia erratica, Nathorst, Arch. Ver. Freund. Nat. Mecklenb. 
Jahr. xliv. p. 1, pl. i. figs. 1 and 2. 
1890. Pecopteris Geyleriana (in part), Nathorst, Denkschr. k. Ak. Wiss. 
math.-nat. Cl. vol. lvii. p. 49, pl. iv. fig. 3 (not the other figures 
of this species). 
Type. Fragments of pinne; pinnules showing venation. The 
specimens on which the genus Weichselia was founded are much 
larger, and consist of long pinne attached to a broad rachis; no 
venation shown. 
The first diagnosis of Weichselia Ludovice is that given by 
Stichler in 1857; the earlier definitions of the English species, 
Lonchopteris Mantelli, were founded on much smaller specimens 
than those which Stiehler had before him :— 
‘“Frons bipinnata, expansa, maxima (5-6-8 pedalis); rhachis 
valida, profunde suleata, apicem versus tenuissime excurrens ; 
pinne terminales subverticales, elongatz, anguste lineares, remotze 
(distantes), reliquee horizontales, convex, approximate, lineari- 
lanceolate, ad 18 poll. usque longe, 3% poll. late, omnes basi 
discrete; pinnule perbreves, oblong, obtuse, integerrime, approxi- 
mate, fructiferee medio, canaliculate, ambitu contractz, steriles 
subplane.’’? 
The following definition includes most of the important characters 
in this peculiar type of fern :— 
Frond bipinnate, rachis broad and rigid, pinne alternate, very 
long, of uniform breadth and with prominent axes; pinnules entire 
with obtusely rounded apex, a midrib and reticulate secondary 
veins, oblong, except towards the distal ends of pinne, where they 
become more or less triangular in shape and have pointed apices, 
attached by the entire base, separate and not confluent; the stiff 
and thick pinnules are usually inclined towards the axis of the 
pinna, and the two rows form with the axis an open V instead of 
lying in a horizontal position. 
The earliest figures and description of Wechselia Mantelli 
(Brong.) are usually attributed to Mantell in the year 1824; the 
paper to which reference is made was written by Stokes and Webb, 
1 Paleontographica, vol. v. 1857, p. 76. 
