66* 



Quercus pokanoides, sp. nov., PL XXX, Fig. 9. 



Leaf broadly oval or nearly round, undulate, obtuse at the top and the base; medial nerve thick , 

 lateral veins thin, mostly opposite, open, curved in passing up to the borders, carnptodrorue. 



The surface of this leaf is polished; its substance rather membranaceous 

 than coriaceous; it is 4 centimeters long and just as large, apparently round or 

 truncate at the point, and rounded to the base in the same way. It is marked 

 by 6 pairs of thin opposite secondary veins, emerging at an angle of 70° to 

 80°, the two lowest pairs more open still, curving and branching near the 

 borders, with intermediate thinner and shorter veinlets. The upper part of 

 the leaf is somewhat erased, and the details of areolation undiscernible. 

 The relation, therefore, of this species to Quercus is not more definite than 

 that of the former. 



Habitat. — Kansas, found in concretions, Mudge. 



Celtis(?) ovata, Lesqx., PL iv, Figs. 2-3. 



Leaves ovate, obtuse or truncate at the point, enlarging toward the base, truncate or abruptly 

 curved to a long petiole ; borders more or less undulate ; nervation palmate from the base, in three cras- 

 pedodrome divisions. 



Populites ovata, Lesqx., American Journal of Science and Arts, (2), xlvi, p. 94. 



This species has some affinity with this genus in the form of the leaves 

 and the palmate nervation. In this last character especially, it resembles the 

 American C. mississippiensis, and C. tourneforti by the form of the leaves, 

 which, however, are crenate in this last species. In Fig. 2, the primary 

 nerves, three only, join the top of the petiole, and ascend, branching more or 

 less, and under angles of divergence of 30°, to the borders. In the second 

 leaf, Fig. 3, the division of the primary veins is more irregular, the branch on 

 the left side being as thick as the medial nerve, and under an angle of 

 divergence of 30°, while the branch of the right side is thin, nearly in a right 

 angle to the medial nerve, appearing like a marginal veinlet, while another 

 branch above it has the normal direction of the primary lateral nerve, but is as 

 thin as the lowest marginal vein. This abnormal division of the nerves, as 

 also the multiplication of the lateral veins, is apparently casual, and cannot 

 indicate a distinction of species for these leaves. Their substance is the 

 same — thickish, membranaceous — and also the areolation, which, in its ultimate 

 divisions, is small, polygonal, derived from large, square continuous areas like 

 that of Platanus, as marked in the enlarged part. The border of the leaves, 

 at least, as seen in this same specimen, cut or rounded at the base to near 

 the petiole, turn abruptly down, and are slightly decurrent. 



Habitat. — Decatur, Nebraska, Hayden. 



