140 



LARAMIE FLORA OF THE DENVER BASIN. 



drome secondaries; lateral ribs at an angle of 

 approximately 45°, thin, passing up about half 

 the length of the leaf; finer nervation obsolete. 



The single example figured is all that was 

 observed of this species. It is 5.5 centimeters 

 long and a little over 4.5 centimeters wide. It 

 appears to be closely related to Ficus ovatifolia 

 Berry, 3 from the Eutaw formation of McBrides 

 Ford, Ga. It is, however, more truncate at 

 the base and more obtuse at the apex, and the 

 lateral ribs do not ascend as high as in the 

 Eutaw form. 



This species is named in honor of Edward 

 Wilber Berry, of Johns Hopkins University. 



Occurrence: Laramie formation, Marshall, 

 Colo., railroad cut between old and new sta- 

 tions, collected by A. C. Peale, 1908. 



Ficus arenacea Lesquereux. 



Plate X, figures 2, 4; Plate XXI, figure 6. 



Ficus arenacea Lesquereux, U. S. Geol. and Geog. Survey 

 Terr. Ann. Rept. for 1871, p. 300, 1872; Tertiary 

 flora: U. S. Geol. Survey Terr. Rept., vol. 7, p. 195, 

 pi. 29, figs. 1, 4, 5, 1878. 



Ficus lanceoldta Heer. Knowlton, U. S. Geol. Survey 

 Bull. 152, p. 102, 1898. 



The early history of this species is the same 

 as that of Ficus lanceolata (now F. navicularis, 

 q. v.) — that is, it is a part of the collection from 

 an unknown locality, the original labels, 

 according to Lesquereux, "having been lost or 

 forgotten." The matrix is a hard, shaly, fine- 

 grained whitish sandstone, and although it was 

 subsequently supposed to have come from the 

 Green River formation it probably came from 

 the Laramie. In any event, the two frag- 

 mentary leaves from the Laramie at Marshall 

 here figured are not to be distinguished from 

 figure 4 of Plate XXIX of Lesquereux's 

 "Tertiary flora," and the species may now 

 take definite place in the Laramie flora. 



Occurrence: Laramie formation, Marshall, 

 Colo., collected by Arthur Lakes, 1890. 



Ficus? apiculatus Knowlton, n. sp. 



Plate XI, figure 6. 



Ficus? apiculatus Knowlton [nomen nudum], U. S. Geol. 

 Survey Bull. 696, p. 270, 1919. 



Leaf membranaceous, ovate-lanceolate, being 

 abruptly rounded below and prolonged above 

 into a long, slender acuminate apex; margin 



s Berry, E. W., U. S. Geol. Survey Prof. Paper 84, pi. 19, figs. 5-7. 

 1914. 



entire; nervation consisting of a rather strong 

 midrib and four or five pairs of thin, remote 

 secondaries, which curve upward and follow 

 the margin for a considerable distance; finer 

 nervation very obscure. 



This leaf, the only one observed, is nearly 

 perfect, as it lacks only the basal portion. It 

 is about 12 centimeters long and 3.5 centimeters 

 wide and may be known by its ovate-lanceolate 

 outline with long, slender tip and the few curv- 

 ing secondaries. 



This species has the same shape of leaf and 

 type of nervation as , Ficus populina Heer, 4 

 from the Swiss Miocene, but it differs abso- 

 lutely in the margin, which is entire in the 

 present species and crenate in the European 

 form. It is perhaps doubtful whether this leaf 

 should be referred to Ficus. 



Occurrence: Laramie formation, Cowan sta- 

 tion, south of Denver, Colo., collected by F. H. 

 Knowlton, 1908. 



Order ARISTOLOCHIALES. 



Family ARISTOLOCHIACEAE. 



Aristolochia brittoni Knowlton, n. sp. 



Plate XXIII, figures 3-5. 



Arislolochia brittoni Knowlton [nomen nudum], U.. S. 

 Geol. Survey Bull. 696, p. 96, 1919. 



Leaves of medium size, broadly reniform, 

 with rounded lobes, a deep rounded sinus, 

 entire margin, and abruptly acuminate or 

 obtuse apex; petiole very thick; nervation pal- 

 mately three-ribbed from the very base of the 

 blade; midrib thick, especially below, becoming 

 flexuose in the upper portion, three or four 

 pairs of alternate secondaries above the middle, 

 arising at an angle of approximately 35°, fork- 

 ing well below the margin, and each joining 

 the one next above by a broad loop and with 

 one or two series of loops outside; lateral ribs 

 strong, arising at an angle of about 45°, passing 

 upward, and joining the lowest secondary on 

 the midrib by a broad loop, each with about 

 four secondary branches on the outside, which 

 arch and join similarly to the upper secondaries; 

 the lowest pair of secondaries with about four 

 tertiary anastomosing branches on the .lower 

 side, supplying the rounded lobes of the blade; 

 nervilles strong, percurrent, forming large rec- 

 tangular areas; ultimate nervation not pre- 

 served. 



4 Flora tertiaria Helvetiae, vol. 2, pi. 85, figs. 4, 5, 1856. 



