^°189o"''] PROCEEDINGS OF THE NATIONAL MUSEUM. 31 



Formation, the age of which has been considerert as Upper Cretaceous. 

 This leaf is figured in Professor Ward's "Types of the Laramie Flora."* 

 and shows, even if the upper part is wanting, a form so much like the 

 leaves I have figured on Plate viii, Figs. 36 and 37, that I do not see 

 any difference at all, as far as concerns the preserved part of it. The 

 margin seems to have been entire and the nervation accords with this 

 variety in all details. 



Three other species have been described by Dr. Newberry {I. c), 

 namely: L. oblongifolmm, L. quercifoUum, and L. simplex, collected in 

 the Amboy clays — Middle Cretaceous — of New Jersey and Long Island. 

 These three forms are large leaves, being deeply-lobed in L. quercifo- 

 Hum, shortly lobed in L. ohlojig [folium, and almost entire margined in L. 

 simiilex. The two first mentioned show a variation analogous to the 

 recent form and the last one is very much like the leaves of very young 

 trees of our living species. L. oblong I folium was a very large-leaved 

 form, of which the leaves were 6 to 8 inches long and 4 to 5 inches wide, 

 and, according to the figure in Dr. Newberry's paper, Plate lxi. Fig. 1, 

 there are four teeth or very short, acute lobes on one side of the leaf. 

 The other half is broken, but shows two lobes which are not quite oppo- 

 site those on the other side. This leaf has, then, been subalternately 

 lobed or rather dentate. There is a distinct notch at the ajiex of the 

 blade, and the base does not taper into the petiole, so that it accords 

 very well with the leaf of a true Uriodcndron, but it may bo a ques- 

 tion whether to consider it as a species or merely as a variety. It looks 

 so very much like the variety from the United States Botanical Gar- 

 den that although it is far from my intention to connect it with the 

 recent type, 1 can but regard it as a variety of a form with more deeply 

 lobed leaves, or in any case as something corresponding to our recent 

 form. The leaf, figured on Plate viii, Fig. 34, shows a somewhat sim- 

 ilar shape having three teeth, which are a little shorter than those of 

 L. oblongifoliiim. In regard to the occurrence of this species, it has 

 been found together with L. qnercifoUum, figured by Dr. Newberry {I. c, 

 Plate LXii, Fig. 1), and this seems to be a very interesting circumstance. 

 This species, L. qnercifoUum, has four pairs of long acuminate lobes, 

 and the size of the leaf was almost the same as indicated for L. oblongi- 

 folium, but did not attain the length nor width of larger specimens of 

 this. That is the same case that I have observed in the recent typical 

 form and the variety from the Botanical Garden, and it is possible that 

 we have, to support this conclusion, an analogous variation before us, 

 rather than two distinct species. It may not be denied, if we will com- 

 pare them with the above-mentioned leaves of the recent type and the 

 variety, that there is a very good accordance, and in that manner, that 

 L. quercifoUum should be the species and L. oblongifoUum its variety. 

 But it is, on the other hand, ditficult to say whether Dr. Newberry's 

 third species, '■' simple x,^^ is a Liriodendron or not, at least according to 

 the figures given by him {I. c), since the nervation is so entirely differ- 

 *Bul]. of U. S- Geol. Survey, 1887, p. 102, Plate XLViii, Fig. 2, 



