(') llV/r(/ — Species of Cj/codeoldea from Moryhtud. 



Siibkingdom 8PERMAT0PHYTA. 



Class GYMXOSl'KKM.Ti. 



Family CYCADACE.E Lin.Uey. 



Subfamily Cvcaukoide.e Robert Brown. 



Fossil cycadean vegetation of INIesozoic age represented I)}' 

 trunks, foliage, and fruits, and embracing a large number of 

 genera and species, the trunks usiiall}' not accompanied by other 

 organs than the bases of the leafstalks, and reproductive axes 

 included in a false bark or "armor" generally of considerable 

 thickness; foliage usuall}' also found separate from other i)arts, 

 and fruits and rarely flowers similarly isolated. The number of 

 genera and species is therefore necessarily duplicated and mul- 

 tiplied, owing to the impossibility of correlating the detached 

 parts, but that those found at similar horizons and localities be- 

 longed together admits of no doubt. The trunks differ in size 

 and form much as do living Cycadacea3 (Cycadere), and characters 

 of all parts show resemblances to existing genera. It is, however, 

 probably incorrect to say that the latter have descended from 

 the f(n-n'ier, or that the fossil forms are embryonic types of the 

 living forms, and the correct conception of the subfamily is em- 

 bodied in the law of sympodial development.* according to which 

 the principal trunk line of descent wduch the fossil forms repre- 

 sent, and wdiich attained its maximum development in Mesozoic 

 time, became extinct, while inferior lines or branches represented 

 by living forms ])ersisted into modern times. This accounts for 

 the lac t so prominently insisted ui)on by Count Solms-Laubach 

 and otliers that the fossil forms, at least those in which the re- 

 ])roductive organs are preserved embedded in the armor of the 

 trunks (Benncttites), are structurally more advanced than the 

 living Cycadacea^ a fact which tinds its counterpart in the Ijcpi- 

 dophyta and Calamarite of the Carboniferous and in the Dino- 

 sauria of the Mesozoic. 



Genu.s Cycadeoidea Buckland. 



1827. Ci/c(tdeo!dea Buckland, Proc. Geol. Soc. London, vol. I, Xo. 8, pp. 



80-81 (session of June 6, 1827). 



1828. Cijcadeoidea Buckland, Trans. Geol. Soc. London, 2d ser., vol. II, 



pp. .';75-401, pi. xlvi-xlix. 



Fossil trunks of Cycadeoidese, chiefly low (30-90 centimeters in height) 

 and more or less conical or oval in sliape (15-75 centimeters in diameter), 



*Prof. Biol. Soc. Washington, vol. Y, Washington, 1890, p. 24. Lester 

 F. Ward: Tiie Course of Biologic; Evolution (reprint of above), p. 2. 



