APPENDIX. 61 



pair being thinner and more like marginal veins than like primary nei 

 For this reason the lobes are not distinct, or scarcely more prominenl than 

 the obtnse large teeth of the borders. By this character this leaf corresponds 

 partly to the first of the subdivisions established by Heer in this description, 



leaves as broad as long, short-lobed, broadly obtusely dentate, and partly to the 

 fourth division, wherein he includes truncate or sub-truncate leaves. The 

 identification of this finely preserved leaf is positive. 



The relation of this species is with the present North American Acer 

 spicatum, the mountain Maple, whose range in the Northern States is from 

 the Atlantic to the Mississippi. 



Acer, species. 



The specimen shows only the middle part of a leaf. It is trilobcd, the lobes 

 separated by deep narrow obtuse sinuses ; coarsely sinuate dentate on the borders. As 

 far as the characters are recognizable, the fragment represents a leaf equally 

 referable to Acer macrophyllum, Pursh, and to Acer grandidentatuni, Nutt. It is 

 intermediate in size, but comes nearer the last of these species, especially 

 similar to a large form of A. grandidentatum, which I collected in the Ogden 

 Canon of Utah. 



It is to be regretted that the fragment is not in a better state of preserva- 

 tion, and that it cannot be ascertained if this leaf of the Pliocene does not 

 positively represent a species intermediate between A. macrophyllum and A. 

 grandidentatum, or an older type, modified by peculiar circumstances forcing it 

 to migrations, partly to the mountains where it became dwarfed, partly to 

 the south wherefrom it returned later and during the present period with 

 an amplitude of foliage resulting from a habitat in a warmer climate. 



Another specimen, No. 50, represents a large leaf, apparently referable to 

 Magnolia lanceolata, p. 24, PL VI. Fig. 4. 



The borders are erased, the nervation is obscure, the determination is not 

 certain. 



In a lot of specimens, sent for examination by Professor William Denton, I found a few fragments of 

 leaves from the Chalk Bluffs, in Nevada County. They represent Quereas cm . L sqx., Aralia Zaddutki, 

 Heer, species already published from the same locality, and an Acer, new for this Mora. It is .1. a ctianum, 

 Sap., a species found in France by the author, in theGypses of Aix, therefore an old type, at least Miocene 

 if not older.* The leaf is three palmately nerved and palmate-trilohate ; the medial lohe longer, and 

 sparingly dentate or minute-lobed ; but the lower part of the leaf is entire. In all its characters it seems 



* Saporta considers the formation as continuous from the upper Cretaceous to the lower Miocene. It has, how- 

 ever, a number of species identified in the Green River Group of the Rocky Mountains. 



