80 THE FLORA OF THE AMBOY CLAYS, 
identical with L. primevum, but the form is quite different, and no connect- 
ing links have been found. Professor Heer also unites with L. Meekii some 
ovate emarginate leaves from the Dakota and Greenland strata, to which he 
formerly gave the names Phyllites obcordatus and Leguminosites Marcouanus ; 
but it is by no means certain that they were borne by the same tree that 
carried the leaves called Liriodendron Meekii. Indeed, the probabilities are 
against it, since no intermediate forms have been found, and none of the 
panduritorm leaves of L. Meekii have been obtained from Greenland, where 
obovate, entire, or emarginate leaves similar to those given the above names 
do occur, and also many of the emarginate, oblong-ovoid, or lanceolate 
leaves which I have called Liriodendropsis simplex. 
Several additional species of Liriodendron are enumerated by Mr. Lesq- 
uereux among the fossil plants of the Dakota group, viz: L. giganteum Lesq., 
L. intermedium Lesq. (Cret. F1., p. 93, Pl. XX, fig. 5; Pl. XXII, fig. 2), Z. 
acuminatum Lesq., L. cruciforme Lesq., L. semi-alatum Lesq., L. pinnatifidum 
Lesq. (Bull. Mus. Comp. Zool., Vol. VI, No. 6, p. 227). As only the first 
two are figured, and these from fragments, and the others very briefly 
described, I am unable to make any satisfactory use of this important 
material in tracing the life history of the genus. 
I have’ elsewhere reported as a remarkable tact that among all the 
great collections of Laramie and Eocene plants made in Washington, Wyo- 
ming, and Colorado, and in the country bordermg the upper Missouri, not 
a single leaf of Liriodendron had yet been identified. Since then a frag- 
mentary specimen has been described from the Laramie strata, Point of 
Rocks, Wyo., by Prof. Lester F. Ward (Bull. 37, U.S. Geol. Survey, p. 102, 
Pl. XLVIII, fig. 2), and during the summer of 1889 numerous leaves of a 
marked species of this genus were obtained by Mr. R. C. Hills from the 
Lower Laramie at Walsenberg, Colo” Thus another link in the chain has 
been supplied. 
Norr.—At the time when the above was written the Flora of the Dakota Group, 
as edited by Dr. Knowlton from Professor Lesquereux’s manuscript, had not been 
published, and Dr. Newberry never saw the still further development of this genus 
as there depicted.— A. H. 
‘Bull. Torrey Bot. Club, Vol. XIV, p. &. 
2. alatum Newb., Hollick in Bull. Torrey Bot. Club, Vol. XXI, p. 467, Pl. CCXX.—A. H. 
