454 MESOZOIC FLOKAb OF UNITED STATES. 



Ctcadeoidea Uhleri Ward. 

 PI. LXXXVII, Fig. IV. 10: PI. C. 

 1897. Cycadeoidea Uhleri Ward: Proc Biol. Soc. Wasliington. Vol. XI, p. 14. 



Trunks small, 28 cm. high, 20 cm. in diameter, 50 cm. to 60 cm. 

 in girth at the thickest part, circular, oi' only slightly elliptical in cross 

 section, conical or somewhat cylindrical-conical in shape, contracted 

 at the base, silicified but porous and light, reddish or gray in color; 

 leaf scars definitely arranged in quincunx order and spiral rows aroimd 

 the trunk, one of these sets of rows ascending at an angle of 45° to the 

 axis, the other at a much greater angle; subtriangular, the upper side 

 arched and sometimes slightly grooved, lateral angles acute, inferior 

 angle obtuse or rounded; scars uniform in size, IS mm. wide and 9 mm. 

 high; ramentum walls 4 mm. to 5 nmi. thick, commissure distinct, the 

 whole punctured with minute rhombic, triangular, or elliptical liract 

 scars deeply penetrating the structures; leaf bases usually wanting, 

 but sometimes nearly filling the cavities ; vascular bundles few, arranged 

 in a row near the upper side of the petiole and others scattered over 

 other parts; petioles all reflexed or pointing downward at a strong 

 angle; reproductive organs numerous, situated directly over the leaf 

 scars — i. e., axillary — elliptical in outline, 15 mm. wide, 10 mm. high, 

 the center occupied by the remains of the essential organs or b}' a cir- 

 cular cavity where these have disappeared ; bract scars small and numer- 

 ous, somewhat curved and arranged concentricall}' around the spadix, 

 also passing out into the ramentum walls; armor 3 cm. to 5 cm. thick; 

 woody zone 15 mm. to 35 mm. thick, divided into two or three rings; 

 medulla about 5 cm. in diameter, cylindrical or elliptical according to 

 the shape of the trunk, heterogeneous in composition, being traversed 

 by dikelike plates of a hard substance dividing it into chambers, often 

 wanting, leaving a hollow center to the trunk. 



No additional specimens of this species have come to light since 

 it was described in 1897 from the two types then known. One of these 

 is as perfect a specimen as any in the collections, and the species is one 

 of the most distinct and well characterized of all of the fossil cycads. 



PI. LXXXVII, Fig. IV, 10, shows the external surface of the Crook 

 fragment, No. 2, W. C, B., No. 1429. The trunk from which it was 



