SAGENOPTERIS 129 
Lateral veins very regular and numerous. No sign of branching. 
Cf. Oleandridium Eurychoron, Schenk, Paleontographica, vol. xxxi. 
1885, p. 168, pl. xiii. figs. 3-5 and pl. xv. fig. 2. Ecclesbourne. 
Rufford Coll. 
V. 2383. Fragment showing the same type of venation. Fair- 
light. Rufford Coll. 
Genus SAGENOPTERIS, Presl. 
[Sternberg, Flora der Vorwelt, vii. 1838, p. 164.] 
The genus is thus defined in Sternberg’s Flora :— 
“Frons pinnata, pinnis ternatim rarius binatim compositis. 
Vene tenuissime, ramosissime, equales, in maculas irregulariter 
hexagonoides elongatas confluentes. Coste crassee usque ad apicem 
pinnularum excurrentes.”’ 
Schimper! speaks of Sagenopteris as having no analogue among 
living plants, but notes the obvious resemblance to MJarsilea; this, 
however, he does not regard as evidence of natural affinity. 
Stomata have been found on the lower surface of Sagenopteris, 
but, according to Schimper, there are none on the lower surface 
of Marsilea leaves. 
This argument is dismissed by Nathorst, who has observed 
stomata in the lower epidermal layer of J/arsilea; but the fructi- 
fication of Sagenopteris has been adduced as stronger evidence than 
the mere external resemblance in the leaves of the two plants. The 
so-called sporocarps are described by Nathorst? as abundant in the 
Rheetic beds near Palsjé; they cannot be referred to Conifers or 
Cycads, and, in the absence of Angiosperms, Nathorst is driven to 
regard them as the fructification of a Marsileaceous plant, and, 
therefore, of Sagenopteris, as the only genus that can be included 
in the Jarsileacee. The same conclusion was independently 
arrived at by Heer after examining the Swedish specimens.’ 
1 Trait. pal. vég. vol. i. p. 640. 
2 Foss. Fl. Schwedens, p. 18. 
3 Nathorst, doc. cit. p. 18. 
