E. H. Sellards — Codonotheca. 95 



Figure 12. — Pliotograpli of a small specimen. The first segment on the 

 right is seen from the dorsal surface, showing the parallel striee. The next 

 segment is seen from the ventral (inner) side. The two strong bundles 

 traversing this segment can be traced in the photograph. The origin of these 

 two strands from alternate strands below, which can be distinguished only 

 by close scrutiny in the photograph, is very evident in the specimen. The 

 outline of the resistant area formed by the union of the bundles below can 

 be followed by its white micaceous coating such as often covers the fossils 

 in these nodules. Natural size. 



Figure 13. — The large base is here flattened. The stride of the base are 

 more or less disarranged and have a wavy course. Some of them seem to 

 divide, and all converge to the point of attachment. The photograph also 

 shows the cone-shaped resistant area at the center, which is large above where 

 it breaks up into strands ; pointed below. The first spore-bearing segment 

 on the left is crushed, giving it an unnatural width. At the top of the next 

 one is seen the dorsal surface marked by fine striae. Farther down the seg- 

 ment is removed, leaving the impression of the ventral (inner) surface on 

 which the two bundles supplying the segment are seen. At one point about 

 half-way down, the break extends through to the opposite side of the organ 

 and a few spores are seen in place on the opposite surface. Natural size. 



Figures 14-15. — A specimen worked out so as to expose both sides of the 

 organ. The base of this specimen is not entirely flattened, having partly 

 retained its shape. The side illustrated in the pen drawing, figure 15, shows 

 for the most part the impression (mold) of the outside surface. In places, 

 however, the substance of the plant has clung to the mold. This is true of 

 a part of the vascular system, and the tips of segments VI and I, giving an 

 instructive view of the ventral (inner) surface. The two bundles are distinct, 

 lie near the surface, and are rather widely separated. The segments have 

 considerable thickness as seen in the break, being perhaps half as thick as 

 wide. The impression made by the dorsal surface is longitudinally striate, 

 as seen in the other segments of this and other specimens. The dorsal sur- 

 face of the segment itself is represented in figure 17, showing the parallel 

 striae, and the minutely roughened or pitted surface. The photograph 

 of the opposite side as it lies in the nodule, figure 14, gives a partial dorsal 

 view of segments I and IV, which are crushed laterally and distorted. Seg- 

 ments II and III have i*etained their shape and are seen from the ventral 

 (inner) view. The cone-shaped portion of matrix which originally filled the 

 center of the organ is preserved in the Yale collection, and shows on one side, 

 corresponding to the side from which the photograph was made, the impres- 

 sions of the ventral side of the segments ; while on the other side, that from 

 which the mold serving as the basis of figure 15 came, the dorsal surface of 

 the segments (except the tips of VI and I) are seen. Natural size. 



Figure 16. — Enlarged detail of the petiole ; showing the strong striae and 

 weaker cross lines. x 8. 



Figure 17. — Enlarged detail of dorsal surface of the segment, x 3. 



Figure 18. — An average specimen. Natural size. 



