276 MESOZOIC FLORAS OF UNITED STATES. 



Genus CYCADEOIDEA Bucklaiul. 



CyCADEOIIiI'.A StaXTOM \\':U(I II. sp. 



PI. LXX. 



Ti'uiik of niodium size (23 cm. hijrh. 17 hy '.'A cm. in diameter), 

 conical, much compressed laterally, unltranched, of a lijiht-gray or ash 

 color, firmly silicified, fine grained, rather hard, and of a mediimi specific 

 gravity; organs of the armor horizontal, except near the summit, where 

 they are increasingly ascending, becoming vertical at the apex; leaf 

 scars forming two distinct series of spiral rows around the trunk, those 

 from left to right forming an angle of 30° and those from I'ight to left an 

 angle of 45° with the axis; scars subrhomljic, large, and well developed, 

 3 cm. wide, 5-15 mm. high; leaf bases hard, firm, and fine grained, not 

 porous, their summits sometimes 15 mm. below the surface, sometimes 

 rising 1 cm. above it, but in most cases nearly on a level with it, usually 

 rounded and convex, occasionally broken across, showing a smooth 

 fracture, but more frequently scaled away so as to show an outer layer 

 and a circle of protuberances, which consists of the scars of the vasculai' 

 bundles, a second circle of bundles occurring farther inward, and scattered 

 ones near the center; ramentaceous walls 5 mm. to 1 cm. thick, hard 

 and firm, presenting a creased and plaited appearance with sharp ridges 

 and interrupted grooves, the middle groove representing the union of 

 the contiguous plates; reproductive organs not prominent, very anom- 

 alous, perhaps mostly abortive, very numerous, occupying all the inter- 

 spaces among the leaf scars, very small and indefinite in shape, and only 

 represented by clusters of large and deep pits which fill the angles and 

 occur between the walls of the leaf scars; most of these pits apparently 

 scars of the involucral scales which have disappeared, subtriangular, 

 subrhoml)ic, or somewhat crescent -shaped, 4 mm. by 8 mm. in diameter, 

 othei- more central and circular ones probably representing the essential 

 organs; armor 3 cm. thick on the sides and 7 cm. thick at the ends of 

 the elliptical base, where alone it can be seen, averaging about 5 cm.; 

 woody axis undifferentiated, 6-15 cm. thick, hard and firm; medulla 

 8 cm. by 12 cm. in diameter, somewhat distinctly separated from the 



