IDG rjlOCKKDiyas of TIIE XATIOXAL MISEVM. voi.xxi. 



The loUowiiig is a systematic description of tliesc si)ecies: 



Genus CYCADEOIDEA Buckland. 



IS'27. i'ycadeindea IJrcKLAND, I'loc. (Jcol. Soc, I,oiu1om, I, No. S, ]>ii. ,S0-S1 (sossion (if 



. I line t). 1S27). 

 ISL'8. Ci/cadcoidca IU'cki.and, Tniiis. (icol. Soc, LoikIoh, I'd ser.. II, jip. ;>7r>-l()l, pis. 



xi.vi-xi.ix (volume dated 1S2!), but juouioir jiiobably issued separately in 



1828). 



CYCADEOIDEA DACOTENSIS (McBride) Ward emend. 



1893. lienucltilcn daroleiim.^ McHimdk, in jiait, Auiericau (Jeoiofiist, XII, ]>. L'l!), pi. xi, 



fig. 1 (non r. 2). 

 18!»1. Cyvddvoidea davolciisin (McHkidk) \\'aki>, in p.irt, I'ror. Hiol. Soe., W.'isliiiigtou, 



IX,p,8(). 



Tiiinks large (30 lo ;")(> cm. lii^li, 'M) to 50 cm. in diameter, 100 to 150 

 cm. in girth), short-cylindrical, contracted below, dome-shai)ed above, 

 symmetrical, sometimes laterally compressed and elliptical in cross 

 section, probal)ly snbscfiiuMit to entombment; bearing a number of 

 short secondary a.xes or undeveloped branches in the form ol" rounded 

 protuberanc;es, or, in case oi' decay, of corres]K)nding saucer shaped 

 depressions; apex presenting a tiattened surface with a central eleva- 

 tion studded with polygonal bra(^t scars and bases arranged in rows 

 which sometimes i)rocecd in lu'licoid Ibrm from the center outward; 

 rot'k substai:ce of a dark brown or reddish color, firmly silicified, hard 

 and heavy, sometinuvs weighing over 100 kg., finegrained; organs of 

 the aruu)r slightly ascending except near the base, the angle incrcasiug 

 toward the summit where timy become vertical; leaf scars where uot 

 interrupted forming two series of spiral rows which ])roceed in dilVerent 

 directions and intersect one another, those from right to left nearly 

 horizontal below and curving ui)ward uutil they form an angle of 45° 

 with the vertical a\is, the opposite series less distinct forming a snuill 

 angle (5^^ to 10°) with the axis; scars subriiombic and nearly uniform 

 iu shape, larger beh)w, diminishing upward, the distance between the 

 lateral angles varying from 1(5 to 20 mm,, and that between the vertical 

 angles from 10 to UJ mm., emi)ty from decay of the petioles, at least to 

 considerable dei)th, sometimes to a depth of moie than 5 cm.; inter- 

 spaces between the scars very tiiick, though variable, sometimes IG mm., 

 presenting an undulate or wrinkled surface with indications of deeper 

 lines of separation of the walls; spadices large and somewhat elliptical 

 in outline, the longer axis nearly horizontal, S to 10 cm. long, the shorter 

 nearly vertical and 5 to 7 cm. ; involucral bract scars numerous, arranged 

 in concentric ellipses around the central organs in many somewhat dis- 

 tinct rows, increasing in size from the center outward, subrhombic, 

 triangular, or polygonal iu shai)e, 2 to 20 mm. in diameter, apparently 

 ])assiug insensibly into the normal leaf scars, empty like them* forming 

 deep cavities or puuctatious; essential organs of the buds, llowers, or 



