“*steles’” fluctuates from three to five (Plate INI, figs. 
1 to9). One specimen exhibits five * 
its length (Plate INI, fig. 5): one other shows four 
me 
steles’” throughout 
steles’” at both ends. One specimen shows. three 
steles’” at the other. Two 
oe oe 
steles’” at one end and tour 
oe 
of the “‘steles’” may be seen to join on the exterior sur- 
face. From the appearance of this one specimen there is 
one stelar fusion per four centimeters of stem length, and 
ee 
it seems reasonable to conclude that the ‘‘steles’” anas- 
tomose throughout the length of the stem, though prob- 
wbly not at regular intervals. The maximum and mini- 
mum number of stelar components in JW. Olseniae, trom 
basal to apical portions of the stem, is not known owing 
to our fragmentary material. The evidence at hand in- 
dicates that the stem of JZ. Olseniae possessed a vascular 
core of three to five unit “‘steles,’” widely and unevenly 
spaced around a central parenchymatous core, and in 
varying degrees of coalescence throughout their vertical 
extent. Without the attached leaf bases, it is not possi- 
ble to more than suggest that stelar fusions are associated 
with the insertions of the leaves. 
In M. Olseniae the “‘steles’” are more or less elliptical 
in outline, when seen in transverse sections of the stem, 
and, collectively, appear to be in elliptical arrangement 
wround the central parenchymatous ‘‘pith’” (Plate 
LALIT, figs. 1 and 2; Plate INI, figs. 1 and 2). It is 
possible that the unit ‘‘steles’’ were originally arranged 
in-an-ellipse and the present more flattened arrangement 
is due to compression before mineralization. ‘There is no 
indication of the medullary bundles or **star rings’? which 
constitute such a conspicuous feature of many Kuropean 
species of Medullosa (Plate INIT, figs. 8 to 11). The 
individual stelar units of J. Olseniae are trom one to 
three centimeters in cross sectional diameter, along their 
longer axes. The larger ‘‘steles’” represent stelar fusions 
