History of Monocotyledons. 213 
presents an appearance precisely similar to that of the speci- 
men figured by Carruthers, it is sub-cylindrical in form, and 
in surface view appears to be made up of small plates with 
irregularly crenulated margins ; the smaller and more perfect 
example referred to the same species, exhibits four rows of 
hexagonal plates with much more even margins. Without 
attempting to determine the nature of these fossils, or even 
to decide whether they are casts of an animal or plant 
structure, it may be safely asserted that we are not justified 
in accepting them as proofs of a Jurassic Monocotyledon. 
Zigno 1 quotes this species as an example of a fossil mono- 
cotyledonous plant, but does not offer any comment on the 
value of the identification. 
Kaidacarpum. In a paper on British fossil Pandaneae, 
written in 1868, Carruthers 2 institutes a new genus, Kaida- 
carpum, and defines it as follows : — ‘ Fruit composed of 
pyramidal rhomboidal single-seeded drupes, sessile or sub- 
sessile on a thickened spadix.’ Among other specimens 
included in this genus, there is the imperfectly preserved 
fossil represented in PL XIV, Fig. 4; this rolled and worn 
example from the Lower Greensand beds of Potton was 
named by Carruthers K. minus. It must be pointed out 
that the author of the genus has modified his views as to the 
nature of some of the species, and inclines to the opinion 
that they are rather araucarian than monocotyledonous. In 
Fig. 4 A the external surface shows indistinct traces of spirally 
arranged depressions ; towards the lower end of the cone the 
stout central axis projects and is marked by more clearly 
defined and regular pits. Fig. 4 B represents the central axis 
with portions of the imperfect cone-scales on either side. 
Had we no better specimens than this to guide us, it would, 
perhaps, be rash to express a decided opinion as to botanical 
affinity, but a comparison of the Potton cone with more 
perfect specimens from the Wealden rocks, brings out very 
distinctly a close agreement with the female cones of recent 
1 Loc. cit. Vol. ii, p. 2. 
2 Geol. Mag. 1868, Vol. v, p. 153. 
