380 Systematic Paleontology 



Subfamily PODOCARPEAE 



Genus NAGEIOPSIS Fontaine 

 [Mon. U. S. Geol. Surv., vol. xv, 1890, p. 194.] 



This genus was founded by Fontaine in 1890 for forms apparently- 

 allied to the modern species which make up the Nageia section of the 

 genus Podocarpus. He characterized it as follows : 



" Trees or shrubs with leaves and branches spreading in one plane ; 

 leaves varying much in size and shape; those towards the base of the 

 twigs sometimes smaller than those higher up, distichous mostly, or 

 rarely subdistichous, opposite and persistent, attached by a short, slightly 

 twisted footstalk, usually to the side of the twig, more rarely slightly 

 within the margin on the upper or under surface of the stem, either 

 attenuated towards the base or abruptly rounded off there, at their 

 ends acute or subacute; nerves several, coalescing at base to form a 

 footstalk, forking immediately at the base or a short distance above; 

 then approximately parallel to near the tips of the leaves, where they 

 are somewhat crowded together, but do not converge to a union, ending 

 in or near the extremity." 



The diagnostic characters which deserve emphasis are the branching 

 habit, the persistent leaves and the parallel veins which do not converge 

 to any great extent in the apex of the leaf. These all serve to distin- 

 guish the species of Nageiopsis from the cycadaceous fronds or leaflets 

 with which they are most likely to be confused. The genus Podozamites 

 for example, which is usually considered to be cycadean, although Seward 

 suggests that it may be araucarian, is very similar in appearance; so 

 similar in fact that Professor Fontaine included a number of Podozamites 

 leaflets in his various species of Nag&iopsis. But Podozamites is usually 

 represented by detached leaves, hence it was deciduous in habit; the 

 fronds are not known to branch, which habit is not only a distinguishing 

 character but an argument against an araucarian affinity; finally, the 

 veins converge, more or less, apically. 



It has seemed wiser in considering detached and fragmentary leaves 

 such as are those specimens which have been referred to Nageiopsis from 

 the Shasta, Lakota, and Kootanie horizons to fully indicate their 



