OF THE GENERA ZAMITES AND PTEROPHYLLUM. 117 
obvious similarity of this frond to that of the recent Cycads, especially Ceratozamia. 
He also compared it with Pterophyllum Bronni, Schenk (see p. 120), and referred it to 
the same genus. The special interest of this specimen lies in the fact that the pinnæ 
are attached, apparently laterally, to a. broad rachis. Since the pinnæ are all in 
continuity, it is impossible to say whether a callosity occurs at the base of each. The 
general shape of the leaflets, bearing in mind, as Schenk has pointed out, that the apical 
portions are wanting, as well as the characters of the nervation, lead me to regard it as 
identical with, or scarcely distinguishable from, Zamites grandis, 
Although in Schenk’s specimen the leaflets are apparently attached laterally, it by 
no means follows that such was really the case in the living state. I have already 
commented (p. 113) on the difficulties of ascertaining the exact manner of attachment 
in many specimens of Zamitean fronds. see no reason to regard this leaf as being 
other than a pinnate frond, though Schimper * placed it in a new genus Macropterygium, 
as à new species M. Schenkii. 
If my view of the nature and attribution of Schenk's fossil is correct, then the case in 
favour of the interpretation, here adopted, of the leaflets of Zamites grandis, from 
England and the Vosges, is greatly strengthened. 
Purther evidence may be found in a common fossil from the Stonesfield Slate of 
England, Zamites megaphylius (Phillips), which has recently been redescribed by Prof. 
Seward t. This is a leaflet very closely allied to Zamites grandis, but apparently 
specifically distinct, for the apex is more elongately aeuminate and the pinnz are more 
nearly linear in form. The pinns, as a rule, also occur detached, and may be more 
than 30 em. long. The Cycadean affinity of the frond was, however, early recognised 
in this case, for one of Philipssi type specimens (recently refigured by Seward §) 
shows the leaflets apparently in continuity with the rachis; though here again the 
precise manner of attachment is not very evident. I am in agreement with Prof. Seward 
who says “on the whole I incline to the opinion that the numerous Monocotyledon-like 
leaves from Stonesfield are the pinne of a Cycadean frond” ||. 
Solms-Laubach ¥ has also called attention to the fact that, in some fronds of Zamites, 
the pinnules frequently become isolated from the rachis, and in this condition may 
have been liable to misidentification. 
Lastly, in this connection, it may be pointed out that Cycad-like fronds with very long 
pinnæ have been referred to other genera, in which the leaflets are, in the majority 
of cases, only of moderate length. The Rheetic fossil Podozamites distans, Presl, 
var. longifolia, Schenk **. is a good example. A detached leaflet of such a frond would 
be just as liable to misidentification as one of the pinnæ of Zamites grandis. 
e may therefore conclude, viewing the whole of this evidence, that there are 
strong reasons to be adduced in support of the interpretation of the Keuper fossils 
Maintained here, 
y — (1869), vol, ii. p. 132. 
T Seward (190 5 : d text-fig. 11. 
ud 4), P. 110, pl. 10. figs. 4-5, pl. 12. figs. 1, 3-5, and test-fig 
t Phillips (1871), p. 169, diag. sb RU 6. * $ Seward (1904), p. 114, text-fig. 11. 
! Beward (1904), p. 111. «| Solms-Laubach (1891), p. 88. ** Schenk (1867), p. 162, pl. 37. fig. 1. 
8 
ECOND SERIES. BOTANY, VOL. VII. 2 
