332 NEW YORK STATE MUSEUM 



the fossil, appear narrower and are plainly in vertical series 

 on ribs. It is probable that the form of the lepidodendroid 

 cushions in this area is in part due to obliqueness of com- 

 pression as will later be explained. 



From a hight of 80 cm upward the lepidodendroid form of 

 cushion is constantly more or less in evidence, first along the 

 borders of the fossil, and later throughout its width. The mar- 

 ginal occurrence of rhomboidal cushion impressions is also 

 illustrated, in plate 9, figure 1, from an area 150 cm above the 

 base, where again we find the medial costae relatively narrow, 

 though the cushions, especially on the right near the borders, 

 are broader and slightly overlapped obliquely in the same ver- 

 tical row. The width of the medial rows is evidently fore- 

 shortened by lateral pressure in the process of the flattening of 

 the trunk. This foreshortening indicates the destruction of the 

 inner tissues of this part of the trunk before the compression 

 of the outer cortex. A discontinuity of the cushions and an 

 absence of lateral symmetry are apparent on the right of the 

 photograph, which represents nearly the entire width of the 

 fossil at this point. The small area, shown in plate 9, figure 

 3, about 10 cm higher than that in figure 1, is characterized 

 by broad and unusually compact cushions with more elongated 

 leaf scars. In outline the cushions are lepidodendroid and 

 wholly without costate arrangement, although ill-defined ribs, 

 largely the result of pressure, appear near the median line of 

 the stem. 



In that portion of the trunk above 175 cm from the base the 

 lepidodendroid form of leaf cushion is overwhelmingly dominant 

 though narrow medial costation is still to be seen for some 

 distance farther. The surface at 210 cm shown in plate 9, figure 

 2, presents a still more elongated and asymmetrical obliquely 

 overlapping leaf cushion, whose spiral arrangement is, for the 

 most part, far more distinct than the vertical alinement. The 

 cushions shown in figure 2, like those seen at 270 cm in plate 

 10, figure 2, and especially at 285 cm in plate 10, figure 3, are 

 distinctly lepidodendroid even* to a slight basal truncation, and 

 are practically without costate arrangement. They represent 

 the common Devonic lepidophytic type, referred by all authors 

 to the genus Lepidodendron. 



Near the top of the fossil the Lepidodendron form of leaf 

 cushion is present even along the median line, as may be noted 



