350 
Palaeontologie. 
regarded as Monocotyledonous, Proangiospermic or Cordaitean leaf- 
impressions are in reality the detached pinnae of Cycad-like fronds 
with long and large leaflets. Schimper and Mougeot’s Yuccites 
vogesiacus is shown to be identical with Z. grandis , and reasons 
are given for the institution of the new name. Some of the impres- 
sions described by Zigno and Saporta under Yuccites, by 
Compter under Cordaites und by Velenovsky under Krannera 
are probably also simply detached pinnules or large fronds of the 
Zamitean type. Schenk’s Pterophyllum giganteum is probably a 
leaf of Zamites grandis in which the leaflets are still attached to 
the rachis. 
Zamites grandis is contrasted with the leaves of Noeggerathia, 
Cordaites, Noeggerathiopsis and Podosamites. 
The second portion of the paper is concerned with the Ptero¬ 
phyllum Bronni of Schenk, of which a fine specimen from the Keu¬ 
per of Raibl in Carinthia, now in the Munich Museum, is 
described and figured. After a brief review of the generic charac- 
ters of Pterophyllum, the author points out that the generic attri- 
bution of Schenk’s plant raises a difficult question and one on 
which there has been much difference of opinion in the past. It is 
found that there is a strong probability that in this case also we 
have to deal with the large leaflets of a pinnate frond, which have 
usually become detached from the rachis. The leaflets are compa- 
red with those of species of Sphenosamites, Zamites and Pterophyl¬ 
lum with the conclusion that their affinites lie nearest to the latter 
genus, though in the broadly wedgeshaped form of the pinnae, 
Pterophyllum Bronni does not agree with the other species of that 
genus. In some respects P. Bronni combines characters common to 
several Mesozoic C 3 mad-like fronds. Like Zamites grandis it also 
affords a remarkable example of megaphylly among fossil leaf impre- 
sions. Arber (Cambridge). 
Kidston, R., Preliminary Note on the Internal Structure of 
Sigillaria mamillaris Brongniart and Sigillaria scutellata Brong- 
niart. (Proc. Roy. Soc. Edinburgh. Yol. XXVII. Pt. III, N°. 21. p. 
203—6. with 2 text-figures. 1907.) 
The ribs of these specimens, which were obtained from the 
Halifax Hard Bed of Yorkshire, have been exposed, and exhibit 
the leaf-scars in a fine state of preservation; consequently the spe¬ 
cific identification of the stem has been possible. 
In the specimen of S. mamillaris Brong., the Stele is somewhat 
crushed. The primary xylem (1,50 mm. wide) forms a continuous 
band, whose outer margin is distinctly crenulated, the crenulations 
having slightly flattened apices. The secondary xylem (4 mm. wide) 
consists of regulär rows of tracheids of smaller dimensions than 
those of the primary wood. The structure of 5. mamillaris is closely 
similar to that of Sigillaria elegans. 
The specimen of S. scutellata , has an unbroken vascular axis. 
The stem, somewhat compressed, has a circumference of 15,50 cm. 
and contains 22 ribs, though the Stele has only a circumference of 
about 2 cm. The outer margin of the primary xylem is very feebly 
crenulated, and in some places it is difficult to separate the various 
groups of protoxylem elements, which are small and few in number. 
The occasional absence of a prominent crenulate margin to the 
primary xylem connects this type of stele-structure with those of 
the Lepidodendreae which do not possess a corona. 
