CERTAIN DICOTYLEDONOUS AND CONIFEROUS LEAVES. 253 
various Araucarias, it is evident that there are, in many respects, points of 
agreement between Araucaria excelsa and Araucarites Güpperti, but fewer 
and fewer points of agreement between A. Gdpperti and A. Cunninghamu, 
A. Bidwillü, and A. imbricata. 
| | A. A. A. A, 
Araucarites Gópperti, excelsa. |Cunninghamit.| Bidwillii, | imbricata. 
| — ——— — 
Stomatal Long axis ‘03 mm. ‘033 mm. 035 mm. ‘038 mm. | ‘039 mm. 
pore. Short ,, ‘0175 mm. ‘614 mm. ‘014 mm. ‘Ol mm. | ‘015 mm. 
Vertical Horizontal 
cells. cells. 
Subsidiary | Long „ :024mm. ‘04 mm. | ‘038 mm. 052 mm. ‘022 mm. ‘053 mm. 
epidermal 
cells. Short , ‘012 mm. ‘02 mm. ‘02 mm.| ‘03 mm. ‘016 mm. ‘036 mm. 
Epidermal | 
cells be- | Long „ ‘04 mm. ‘058 mm. ‘058 mm. ‘11 mm. | ‘076 mm. 
tween two | 
stomatal |Short , Olömm. Ol mm. 019 mm. | ‘012 mm. | ‘029 mm. 
series, | | 
| | 
Epidermal | | 
cells be- | Long ,, 025 mm. | ‘026 mm. | ‘034 mm. en *045 mm. 
tween two | | 
stomata of Short „ ‘012 mm. | 016 mm. | ‘032 mm. TED ‘019 mm. 
one series. | | | 
Recent and extinct Araucarias have been described by Seward & Ford 
(1906) very fully, but no details of their epidermal structure other than the pre- 
sence or absence of stomata on the two surfaces are dealt with in their paper. 
It is very evident that all the Araucarias conform as regards their stomata to 
a well-defined morphological type, in which the stomata are serial and indi- 
vidually separate, and occur at the bottom of epidermal pits formed by the 
dipping down of the subsidiary cells surrounding the guard cells. The 
Araucarian leaf-epidermis shows much in common with that of a Sequoia, as 
does also the fossil specimen A. Gópperti, and some Sequoia leaves will now 
be described in order to ascertain whether their cuticular structure shows 
more points of resemblance with Araucarites Güpperti than do the Araucarian 
cuticles. 
SEQUOIA GIGANTEA, Lindl. & Gord. 
External characters of a leaf on a sterile shoot.—Length 5-8 mm., cross 
section triangular to rhombic. Average width 1 mm. Arrangement spiral 
and decussate, adpressed but with free tips. Leaves occurring on the 
shoots bearing cones are shorter, broader, and overlap more. 
