FOSSIL CYCADEAN TRUNKS FROM WYOMING 275 



CYCADELLA RAMENTOSA n. sp. 



Trunks rather large (i5-25cm high, 2-25cm in diameter), cylin- 

 drical or subellipsoidal, somewhat compressed laterally or vertically, 

 mostly unbranched ; rock hard and much mineralized w^ithin, dark 

 brown on the surface, the fractured surfaces variegated with black and 

 white, more or less flinty or chalcedonized ; specific gravity above the 

 mean; organs of the armor horizontal or radiating from an equatorial 

 zone; leaf scars subelliptical, io-i5mm wide, 6-9mm high, hard, 

 dark, rough, punctate with white, tubular pores; walls i-3mm thick, 

 firm and smooth, light colored or yellowish, sunk below the leaf bases, 

 with a median line or groove ; reproductive organs few, mostly con- 

 cealed by the ramentum coating, where exposed well developed, 

 raised above the leaf bases, mostly elliptical and 1 5 x 20mm in diameter, 

 enclosed in an involucre of narrowly rhombic bracts visible in trans- 

 verse and longitudinal section, central portions well shown on frac- 

 tured surfaces, the interior mostly decayed and somewhat crystallized ; 

 armor 4-6cm thick, attached to the axis by an irregular, somewhat 

 scalloped surface ; wood 3cm thick, undifferentiated ; medulla el- 

 liptical in cross-section 3 X 5cm in diameter. 



This species includes ten numbers of Professor Knight's collection, 

 but probably only represents three trunks, since five of these fragments 

 (Nos. 500.40, 500.43, 500.45, 500.66, and 500.81) all fit together 

 and may be built up into a single specimen representing nearly half of 

 one trunk, and Nos. 500.50 and 500.60 also match, forming about one 

 third of another. Nos. 500.39 and 500.55 do not exactly match, but 

 so closely resemble each other that the amount and character of the part 

 lost can be determined with considerable ceilainty. They cannot well 

 belong to either of the other combinations. No. 500.39, is the next 

 most important specimen in the collection in furnishing the generic 

 characters, and slides illustrating them have been prepared from it. 



No. 500.34 is a small apical portion of a trunk of the same type and 

 may well have formed the top of No. 500.39 and the lost piece that 

 belonged with it, but there was a short interval between them, as they 

 do not exactly match. 



The weights of the several fragments in the order of the numbers are 

 as follows : 



No. 500.34, 1.02 kilograms. 

 " 500.39, 2.41 

 " 500.40, 2.04 " 



" 500-43' 1-50 " 

 " 500-45* 1-64 " 



