THE TRIASSIC PERIOD. 39 



factor than now. The great lycopods were almost gone, the last of 

 the sigillarias being among the lingering representatives. Among the 

 gymnosperms, the cordaites were already far down their decline towards 

 extinction, but conifers of the types that had come in during the Per- 

 mian, and kindred new ones, were prominent, while the cycadean group 

 was still in a stage of deployment and occupied the central place of 

 interest. Very much as the ferns in the Carboniferous period were 

 deployed into transition forms (Cycadofilices) , so now the cycadeans 

 had a divergent branch, the Bennettitales, which until recently were 

 classed simply as cycads. The cycads have heretofore been regarded 

 as embracing three groups, the Cycadece, now typified by the Cycas 

 of the eastern hemisphere, the Zamiece similarly typified by the living 

 Zamia of the western hemisphere, and the Bennettitece, a wholly extinct 

 family supposed to be true ancestral cycads; but recent investigations 

 have shown that the last differ from the others so much in structure 

 and mode of fruiting as to require their recognition as a divergent 

 type. While this divergence is universally recognized, some paleo- 

 botanists conservatively leave the group in the class Cycadales, under 

 the name. Bennettitece, while others make it a separate class, Ben- 

 nettitales. 1 It is at any rate cycadean in the broad sense of the term. 

 Besides many structural peculiarities which cannot be noted 

 here, the seed of the Bennettitales had certain angiospermous features. 

 Suggestive as this fact is, it is not to be inferred that the Ben- 

 nettitales were the ancestors of the angiosperms, for this is regarded 

 as improbable. In many cases the imperfect relics of Triassic species 

 do not afford the criteria for distinguishing between the Bennettitales 

 and the Cycadales, and such forms can only be spoken of as cycadeans. 

 It is probable that the majority of the known species were bennetti- 

 talian, but the true cycad branch was probably represented. Among 

 the genera referable to the group were Zamites (Fig. 338, e, /), Otoza- 

 mites (Fig. 338, i), Podozamites (Fig. 338, /), Pterophyllum, Ctenophyl- 

 lum, and Cycadeomyelon, the last, at least, identified as bennettitalian. 

 The Triassic conifers bore the scrawny aspect of the walchias and 

 voltzias of the Permian. They deployed into many new genera of 

 like types, such as Palissija (Fig. 338, a), Braclujphyllum (Fig. 338, c), 



1 Scott, Studies in Fossil Botany, 1900, pp. 445-475; Coulter, Seed Plants, 1901, 

 pp. 142-150; Ward, Older Mesozoic Floras of U. S., 20th Ann. Rep. U. S. Geol. Surv. 

 II, pp. 242-248, 1898-1899. 



