FONTAINE. ] THE EMMONS COLLECTION. 313 
so-called scales, are by far the most common forms of the plant, and 
Emmons has collected a large number of them. In order to give some 
idea of the fossil, it will be best to begin with the detached, single 
object, which, for convenience of description and for lack of a 
name, we may call a scale. There is no evidence, however, that it is 
a scale like that of the cone of a conifer. The epidermal tissue of the 
scales, which is in many cases preserved, is exactly like that of Zyud- 
setum Fogersit, which is seen when the exterior surface of the sheaths 
of this plant isshown. One of the scales is represented in P]. XLVII, 
Fig. 5, which gives a complete form, as made out from a number of 
imperfect ones. The scale is long and narrow, gradually diminishing 
from one end to the other, so as to have a wedge shape. The broader 
end has a curving cord-like termination, which may or may not have 
attached to it a patch of epidermal tissue, which is approximately tri- 
angular inform. From the broad end it narrows gradually, as stated, 
to greater or less lengths, and in the case of detached single scales 
terminates with no particular shape. The detached scales have very 
varying lengths, which seem to depend upon the accidental mode of 
preservation, rather than upon any definite original length. When 
the scales are grouped and attached they, with the single exception of 
the disk depicted in Pl. XLVII, Fig. 4, have their narrower ends 
radiating from a poorly defined depressed ring, which is apparently 
the imprint of a hollow cylinder, which stood at right angles to the 
plane of cleavage of the shale. This ring may be approximately cir- 
cular or elliptical. It is of various sizes, and there is no indication 
that the space within it ever contained any carbonaceous matter. 
Figs. 1 and 2 of Pl. XLVIII give portions of such rings, with scales 
radiating from them. These are the most complete specimens seen, 
and the nearest approach to Emmons’s Z. ellipticus that were seen. 
In each scale there is a keel that starts in the cord-like rim of its 
broad end. Where it springs from the rim it is very broad, but nar- 
rows suddenly, and then continues narrowing very gradually until it 
disappears toward the narrow end of the scale. These keels look 
much like casts in relief of the depressed lines of the sheath of Zgui- 
setum Rogersic that run down between each tooth. From an exam- 
ination of all the specimens I got the impression that Emmons’s 
L. ellipticus, when most complete, is composed of more or less closely 
placed scales, radiating from the central rim, and having their cord- 
like terminations at the free ends connected more or less fully to form 
an outer ring. It is, of course, difficult to judge of the correctness of 
Emmons’s description and figure of Z. edipticus unless one knows 
what he actually saw. It also makes a great difference in judging the 
character of a plant if one collects the specimens himself. Much may 
be seen in the rock that is ruined in collecting, and much that is sig- 
nificant may be neglected. Hence I feel a hesitation in coming to a 
