218 R. L. JACK AND R. ETHERIDGE, JUN., ON PLANTS
fine-grained matrix, or thin carbonaceous black films left by the soft cellular tissue. They are ornamented either with a series of pucker- like depressions, when viewed from the interior, or with a number of wart-like eminences, when seen externally. These are the scars of the points of issue of the vascular bundles passing to the leaves. Along the margins of the stems are a series of spine- or thorn-like projections, which may be the leaves themselves or only their per- sistent bases, and are apparently arranged in spirally oblique rows. They appear to be impunctate, although Mr. Carruthers thinks he has detected a cicatrix in one or two of them. In some of the specimens, around and near the scars, are a series of indistinct longitudinal more or less parallel lines, or perhaps wrinkles. Either as a faint impressed line on the surface of the micaceous matrix, or as a slender flattened carbonaceous band, is seen the internal axis of the stems, p
