SOME RECENT AND FOSSIL FAGACEÆ. 437 
Summary of the General Characters of the Cuticles of the Genus Fagus. 
The cutieles have broad, usually isodiametric stomata flattened at the poles, 
the individual stomata varying in size and being restricted to the lower sur- 
face, where they are usually in definite groups. The poral rims of the guard 
cells are slightly thickened ; their line of junction is usually delicate, or with 
very slight thickening, but with no definite “dagger” or “T” piece of cutin 
except in F. grandifolia. The absence of this “dagger” of cutin and the 
extreme thinness of the outer walls of the guard cells broadly distinguish 
the genus Fagus from Nothofagus, but species of the latter approximate to 
the former in this respect, while a few species of Fagus exhibit all the cuti- 
nizations of Nothofagus, although the thickenings are much slighter. As far 
as cuticular structure is concerned, the species of Fagus and Nothofagus form 
a continuous series. The guard cells of Fugus tend to be somewhat smaller 
than those of Nothofagus, and there is less average agreement in stomatal 
measurements between the different species than is the case in Nothofagus. 
The epidermal cells of Fagus may be sinuate or straight, or one surface 
only, either upper or lower, ntay be sinuate. Thus X. sinensis has a sinuate- 
walled upper epidermis and a straight-walled lower epidermis. Fagus 
Engleriana has both surfaces composed of straight-walled or minutely sinuate 
cells. Fagus sylvatica is very variable in the amount of sinuation of its 
cells; therefore sinuation in these genera is not a character of systematic 
importance. 
Taking certain pairs of closely similar forms about whose relationship 
there has been considerable argument, we may note that the stomata and 
epidermal cells of Fagus sinensis are larger than those of Fagus Eingleriana, 
there are far fewer hairs in the former, and the upper epidermis is sinuate. 
When we compare Fagus sylvatica with Fagus orientalis, we find that though 
both these species have delicate cuticles, there is more eutinization in Æ. orien- 
talis than in F. sylvatica, for not only has the former stomata with thickened 
rims, but there are also slight thickenings ai the janctions of the guard cells, 
which have, moreover, some horizontal eutinizatiou. In Fagus sylvatica the line 
of junction of the guard cells is very delicate, and there is little or no hori- 
zontal eutinization. The epidermal cells of the upper surface are larger in 
F. orientalis than in F. sylvatica, and they are finely sinuate on both surfaces. 
The epidermal cells and venule cells of the recent and fossil forms have all 
been measured and tabulated, but no general conclusions can be drawn 
except that on the whole the cells are the same size throughout the two genera. 
FAGUS BOURNENSIS, sp. nov. (Pl. 40. figs. 34-36.) 
Occurrence. Bournemouth Beds, Eocene. 
Locality. Cliffs between Alum Chine and Middle Chine, 
External Characters (Pl. 40. fig. 34).—Leaf simple ; apex and part of right 
half missing. Length 6 em., width 45 cm. Margin sinuate dentate. Base 
