THE ANATOMY AND AFFINITY OF STROM ATOPTER IS MONILIFORMIS, METT. 139 
straight and massive brown scale which projects freely from the surface of the stem 
(text-fig. 13). On the other hand, there are small, simple, unicellular and multicellular 
hairs which clothe the greater part of the stem surface but are not raised on emer- 
gences. Typical examples of these are given in text-fig. 12. Besides these are 
curious structures which appear to be modifications or combinations of the smaller 
emergences and the simple hairs. In text-fig. 3 is represented the external aspect 
of a dome-shaped emergence, while a sectional view of a similar, though somewhat 
smaller, dome is shown in text-fig. 4. As will be seen from the latter figure, the 
outer walls of these domes are thick, and the inner walls are both thick and pitted. 
Combinations of the emergence and the hair are not uncommon, though in these, 
as a rule, the emergence is low and the hair short (text-fig. 7). But apart from these 
types other and more aberrant forms are frequently encountered. In some cases the 
latter are low mounds bearing single spherical cells with conspicuously pitted outer 
walls (text-fig. 5). In other cases the emergence is more massive, and springing from 
a depression on its broad upper surface is a large, irregular, flask-shaped cell devoid of 
pits (text-fig. 6). Qf still more elaborate and irregular form are such types as are 
shown in text-figs. 8, 9, and 10. In the first of these the emergence is low, and the 
linear series of cells forming the hair is laterally inserted. In the second a similar 
arrangement of parts is seen, but, instead of a simple hair, there is a more massive 
columnar structure with a curious and pitted terminal cell. The most elaborate 
appendage of this type found is shown in text-fig. 10. The emergence which bears 
it is fairly prominent, and the body of the appendage is dome-shaped and raised 
upon a one-celled stalk. A conspicuously pitted cell is borne upon its side, while 
from the basal margin of the dome springs a hair which lies close to the surface of 
the emergence. Many of these elaborate .appendages were examined, and, although 
a remarkable variety of details was observed in them, they resembled each other in 
being pressed close to the surface of the stem, and, as a rule, in possessing cells with 
pitted outer walls. 
But irregularity of form is not confined to the smaller appendages. It is ex- 
tended to the scales also, and in our specimens the straight lanceolate scale is not 
the dominant type. In the majority of cases the scales are tortuous or branched, 
