OF THE GENERA ZAMITES AND PTEROPHYLLUM. 113 
acuminate and tapering or obtusely rounded, the base may be abruptly rounded and 
marked with a callosity near the point of attachment, or the pinnæ may be slightly and 
gradually narrowed towards the base, margins entire; veins parallel, but slightly 
divergent in the apical portion of each pinna." 
This definition is of a somewhat wider nature than Schimper’s, especially as regards 
the characters of the bases of the pinnæ. The author states, however, that “such a 
definition is perhaps suggestive of a genus with characters expressed in too general 
terms, and not sufficiently limited." Prof. Seward also lays great stress on the attach- 
ment of the pinnz to the upper surface of the rachis, but even in species in which there 
is every reason to believe this is the case, it is a feature which is often very difficult to 
establish, and thus usually of slight value as a help towards a correct determination 
of the genus. Often when the rachis has been considerably flattened, and especially 
when the lower surface of the frond is viewed, the leaflets may appear to be attached 
laterally, though better specimens show that in reality such is not the case. In regard 
to the very species, Zamites buchianus (Ett.) to which Prof. Seward points as a fossil 
showing the true mode of attachment of the leaflets, there are many examples in the 
British Museum, and also in the Cambridge Museum, which would lead one to a 
false conclusion. Nathorst * has already instanced similar specimens from Japan. I 
am therefore not disposed to attach much importance to this character of the genus 
as an aid to its identification. As we shall see (p. 116) in the single instance in which 
the leaflets of the species of Zamites, described here, have been found attached to the 
rachis, the insertion appears to be lateral, although in reality it may have been dorsal. 
On the whole, I consider Schimper’s definition the most satisfactory as yet available. 
The fossils described here will be found to agree with it in detail. 
The Species ZAMITES GRANDIS, nom. nov. (P1.17; Pl. 18. fig. 2 ; Pl. 19. figs. 1-3.) 
1844. Yuccites vogesiacus, Schimper & Mougeot, Monogr. Plant. foss. Vosges, p. 42, pl. 21. figs. 1, 2. 
1844. Yuccites dubius, Schimper & Mougeot, ibid. foot of pl. 21. 
1865. Pterophyllum giganteum, Schenk, Flora Schwarz. Schiefer, Raibl, p. 18, pl. 2. fig. 2. 
1870. Yuccites vogesiacus, Schimper, Traité, vol. ii. p. 427. 
1870. Macropterygium schenkii, Schimper, ibid. p. 133. 
1907. Zamites vogesiacus, Arber, in Wills, Geol. Mag. dec. 5, vol. iv. p. 32. 
Localities.—The Bunter of the Vosges (Alsace), Germany; the Keuper of Bromsgrove 
(Worcestershire), England; the Lower Keuper of Raibl (Carinthia), Austria; and ? the 
Lower Keuper of Apolda (East Thuringia), Germany. 
Diagnosis — Frond pinnate. Pinnæ very large, most frequently detached, varying 
sreatly in size, from 30-50 cm. in length and from 3-6'5 cm. or more at their greatest 
width, entire, lanceolate or somewhat linear-lanceolate; apex elongate, acuminate ; 
base somewhat abruptly contracted, with a fairly well-marked callosity at the point of 
attachment, basal margin crescentic. Nerves strictly parallel, occasionally dichoto- 
mising, stout, close, numerous, not spreading nor diverging. Surface much puckered 
and pitted. 
* Nathorst (1890), p. 46. 
