PROTOPTERIS. 73 
Stenzel! has referred to several Protopteris species in his 
important communication on Lhizodendron Oppoliense, Goppert ; 
he points out that P. Cottai should be regarded as a synonym of 
P. Cotteana, Presl, and refers the specimen described in 1865 by 
Goppert? as P. Sternbergii to a new species, P. fibrosa, Stenz. 
Protopteris Witteana, Schenk. 
Pie 
The most important specimen of Protopteris Witteana from a 
botanical point of view is represented in Pl. XI.; it is in all 
probability from the English Wealden rocks, but unfortunately the 
registered number is partly illegible, and cannot be identified with 
any entry in the MSS. Catalogue of the Geological Collections. 
This piece of stem has probably been slightly compressed, and 
the external surface suggests considerable rolling ; it tapers slightly 
towards both of the bluntly rounded ends. The internal structure 
is partially preserved, apparently in carbonate of lime, but the 
details are very imperfectly shown in microscopic sections. On 
the smooth water-worn surface the petiole bases are seen to be 
broadly oval in form, and slightly projecting above the general 
level of the stem; in each leaf-scar the horse-shoe vascular bundle 
is more or less clearly marked. Fig. 3, Pl. XI.° shows one of the 
more perfect leaf-trace bundles at ¢, and external to this at s the 
peripheral sclerenchymatous tissue of the petiole; such a form 
agrees more closely with that of Protopteris Witteana as figured 
by Schenk, than with the more constricted form of P. punctata. 
In the immediate neighbourhood of the leaf-trace there are a few 
small circular markings, and occasionally these show two con- 
centric circles, as at 7.r. in Fig. 3; the inner no doubt representing 
the vascular axis, and the outer the peripheral limits of an 
adventitious root. In the same Figure at r’.7’. there are oblique 
longitudinal sections of adventitious roots. In some of the leaf- 
trace bundles it is possible to see clearly the peripheral stereome 
tissue of the petiole base, which weathering agencies have 
occasionally left in relief immediately above the upper end of 
the vascular strand; e.g. at s, Fig. 1. 
There is a very striking resemblance between the more perfectly 
1 Jahres-Ber. Schles. Ges. Kultur, 1886. 
2 N. Jahrb. 1865, p. 395. 
3 This drawing is made from the ground-down surface of the specimen. 
