EXPLANATION OF THE ILLUSTRATION 
Prare LXT. Stelar organization in the genus Medullosa, Figs. 1-9, 
Medullosa Olseniae; figs. 10, 11, Carboniferous species, 
Mie. 1. Reconstruction of the vascular system of MW. O/seniae, showing 
. . ee as . . . . - 
the flat ring of “‘steles,** based on specimen diagrammed in fig. 5, 
and oriented similarly, ‘The crushed internal parenchyma has been 
restored to its assumed dimensions. 1.5 
Fig. 2, Reconstruction of the vascular system in another specimen of 
M. Olseniae, based on the specimen drawn in fig. +, and oriented simi- 
larly. The largest “‘stele’’ appears to be the result of the fusion of 
two. (See fig. 6 and 7.) 1.5 
Fig, 3. Drawing of the specimen diagrammed in figs. 6 and 7, to 
show the appearance of the fossils. (See fig. 7.) © 1.5 
Fig. +. Stelar organization of the one specimen which shows un- 
crushed internal parenchyma. (See Plate LXTII, fig. 1)» 1.5 
Mig. 5. Diagram of the specimen containing portions of five “‘steles.* 
(See Plate LXIII, fig. 2.) ».1.5 
Fig. 6. Appearance of one end of specimen which shows a stelar fu- 
sion. Steles 5 and 4+ are separate. © 1.5 
Fig. 7. Appearance of the other end of the specimen drawn in fig. 
= 
6. Steles 3 and + have fused, “1.5 
Fig, 8. A less complete specimen of M. Olseniae, which shows second- 
ary wood on both sides of the primary body,» 1.5 
Mig. ® Another specimen of MW. Olseniae, which contains a virtually 
oe es 
complete “‘stele. . 1.0 
Fig. 10. M. pusilla Scott. From Baxter, after Andrews, ~ 1.8 
S 
Mie. Ll. M. distelica Schopf. From Baxter, after Andrews. 1.8 
s 
