109 



ters broad, both having the same form: linear, abruptly rounded to the petiole, 

 and curving or deflexed to it, nearly truncate or broadly deltoid at the point. 

 Both leaves, also, have a comparatively thick medial nerve, and thin, more or 

 less obsolete secondary veins, emerging at a broad angle of 50° to 60°, undu- 

 lating in passing to the borders, and anastomosing with branches of the veins 

 above, camptodrome. 



There is apparently a great difference between these two leaves, espe- 

 cially in the borders, which in Fig. 3 are merely undulate, while in the large 

 leaf they appear undulate-crenate, a character which, to my knowledge, is not 

 recognized in any living species of the Magnoliaceee nor of the Anonacece, 

 some of which have a nervation and areolation somewhat similar to that of 

 this leaf. This denticulation of the borders, however, may not be normal. 

 In the upper part of the large leaf, especially on the right side of the figure, 

 the denticulation is more marked than seen upon the specimens, whose 

 borders are somewhat obscurely marked or as reflexed, and not more deeply 

 undulate than as they are seen on the left side. 



I have referred, these leaves, as advised by Saporta, to the genus Celas- 

 trophyUum, Ett., one species of which is described in the Cretaceous Flora v. 

 Niedershoena, (p. 26, PI. iii, Fig. 9,) under the specific name of C. lanceolatum. 

 The reference of our leaves to this genus is not, however, positive ; but their 

 relation is still less marked with Magnolia crassifolia, Gopp., of the Tertiary 

 of Silesia, to which I compared them formerly. The areolation is represented 

 in Fig. 3 as distinctly as it can be seen. Though the end of the veins is 

 effaced near the borders, they appear really camptodrome. This nervation 

 has its analogy in species of Oxandra, as O. laurifolia, Rich., of Cuba, of 

 which some of the leaves, at least, are abruptly pointed or obtusely acuminate. 



Habitat. — South Kansas, Mudge ; also six miles south of Fort Harker. 



Rhamnus tenax, Lesqx , PI. xxi, Fig. 4. 



Leaf eDtire, lanceolate-pointed, narrowed by a curve to a short petiole ; lateral veins close, numer- 

 ous, thin, parallel. 



Rhamnus tenax, Lesqx., American Journal of Science and Arts, loc. cit., p. 1 01 



A fine leaf, attached to a branch by a short petiole. Its substance is not 

 thick ; its form lanceolate, tapering upward to a slightly obtuse point, and 

 more abruptly downward from below the middle to the petiole. It is 9 cen- 

 timeters long, with the petiole, which is about one centimeter and a little more 

 than two centimeters wide in its broadest part. The thin lateral veins are 



