404 EXPLANATION OF PLATES I. AND II. 



that of T. canadensis, being generally about 0'44 inch in 

 length and about one-fifth part as wide ; or, more precisely, 

 the breadth of the lamina is 0*09 inch, which is somewhat 

 broader in proportion than the leaf of the common yew. 

 The outline of the leaf is linear with a slightly lanceolate 

 narrowing near the apex, which is rounded without any 

 perceptible projection of the mid-rib. Yet though the 

 matrix has rendered the most delicate impressions of the 

 surface, an actually existing minute projection of the mid- 

 rib may have been obscured, owing to the convexity of the 

 lamina ; for on making casts of the common and American 

 yew leaves in Paris plaster, the acute apices of the mid-ribs 

 were not distinctly shewn. The footstalk is as short or 

 shorter than in the common yew, and appears to have had 

 the same kind of half twist which gives the distichous 

 direction to the leaves. The surface of the lamina is 

 slightly convex, with about as much recurvature of the 

 edges as in the Canadian yew, and there is a regular fine 

 undulation, or obtuse transverse wrinkling, which is per- 

 ceptible in all the impressions when they are examined 

 with a lens ; but, except the straight, tapering, prominent 

 mid- rib, there are no veins. 



Owing to the distichous attachment of the leaves, the 

 impressions of the adnate scales of the bark to which the 

 footstalks are jointed are oblique, and the proper form of 

 the scales is not easily determined. They do not appear, 

 however, to have differed greatly from those of the common 

 yew. The elevated triangular areas shewn in the stem of 

 the figure were depressions in the plant between adjacent 

 scales of the bark. In a few specimens the tops of the 

 twigs are shewn to have had an arrangement similar to that 

 of the yew. Buds are numerous in the axils of the leaves of 

 the annotinous spray of yew, and a few impressed hollows 

 in the fossils may have been caused by such bodies, but 

 they are comparatively rare. More numerous small de- 

 tached bodies in the matrix may have been produced by 

 the berries or nuts of this plant. Five or six of the twigs 



