FONTAINE. ] THE OROVILLE FLORA. . 355 
‘expanded at base, closely placed, and in some cases touch one another. 
The leaflets vary in width. The largest obtained has a width of 4 cm. 
and a length of 20 cm., being only a fragment with the terminal part 
not preserved. This is represented in Pl. LVI, Fig. 6. The nerves 
are very strong and single. They go off at a large angle and are 
approximately parallel in their course. They anastomose at long 
intervals, so as to form very much elongated meshes. The mode of 
anastomosis was not fully made out. It is apparently as follows: A 
nerve forks dichotomously, one branch continues the course of the 
original nerve, the other coalesces with an adjacent one. This union 
takes place rarely near the bases of the leaves, and more freely at a 
distance of 3 or 4.cm. above the base of the leaflet. This more frequent 
anastomosis appears to occur also at the same interval, toward the 
middle and terminal portions of the leaflets. This, however, could 
not be clearly made out, owing to the fragmentary condition and 
imperfect preservation of the leaflets.’ 
A number of fragments of this fine cycadaceous plant were found at 
the locality ‘‘In the bed of a ravine that leads from the Banner mine,” 
etc., that indicate that it obtained a gigantic size. Pl. LVII shows a 
leaf with several leafiets in fragments, only the basal portions being 
represented. The leaflets here are of the smallest size. Pl. LVI, Fig. 
6, gives a portion of a leaflet of the largest size, Fig. 7 represents 
the restoration of a portion of a leaflet, to show the nervation and 
mode of insertion. Pl. LIII, Fig. 2, shows the general habit of the 
plant. 
This plant and the two to be next described belong to a type that 
is not common, and which seems to be complex in character. The 
general aspect reminds one of the large Pterophylla of the Rajmahal 
series, especially of Pterophyllum princeps Oldh. and Morr.,* but 
this does not have similar nerves. Perhaps they should be placed ina 
new genus, but they are near enough to the Ctenis falcata of Lindley and 
Hutton? to be placed in the same genus with it. The chief difference 
is the much greater size of the Oroville plant. Nathorst’s Ctenis 
fallax and Ctenis imbricata Font. of the Potomac of Virginia belong 
to the same type, but are specifically different. A noteworthy feature 
of this plant is the unequal width of the leaflets, and in this respect it 
resembles Nilsonia. 
1 Fossil Flora of the Rajmahal Series, pl. x, fig. 3. 
2¥Fossil Flora of Great Britain, Vol. III, pl. ciii. 
