164 



LARAMIE FLORA OF THE DENVER BASIN. 



angle and are provided with secondary branches 

 on the lower side. The margin of the blade 

 seems to be entire for a short distance above 

 the base, then strongly undulate-sinuate. The 

 nervation all appears to be craspedodrome, 

 ending in the large marginal teeth. 



The poor state of preservation makes it 

 difficult properly to place this leaf, but on the 

 whole it appears to be most like the several 

 species of Dombeyopsis figured by Lesquereux, 

 and I have provisionally referred it to that 

 genus. It is larger than even the largest leaf 

 figured by Lesquereux and differs in being quasi 

 five-ribbed and in having a looser, more forked 

 nervation. It is perhaps closest to Dombeyopsis 

 platanoides Lesquereux, 65 from the Bozeman 

 coal field, Mont., but has a much more sinuate- 

 toothed margin and a different nervation. 



A specimen has been found among the Coal 

 Creek material which seems to belong- with' 

 this species. This specimen is much broken 

 but was evidently a leaf of large size. It is 

 more deeply heart-shaped than the first and 

 has an enormously thick midrib and lateral 

 ribs. Except as regards size it has exactly 

 the same character of nervation as the type, 

 including the secondary ribs at right angles 

 to the midrib and below the strong lateral 

 ribs; the nervilles are also the same. 



I am in doubt as to the correctness of refer- 

 ring these leaves to Dombeyopsis, but they may 

 perhaps remain here until more nearly perfect 

 examples are forthcoming. 



Occurrence : Laramie formation, Coal Creek, 

 Boulder County, Colo. (type). 



Dombeyopsis ovata Knowlton. n. sp. 



Plate XXIV, figures 1-3, 9. 



Dombeyopsis ovata Knowlton [nomen nudum], U. S. Geol. 

 Survey Bull. 696, p. 243, 1919. 



Leaves rather membranaceous, ovate in gen- 

 eral, outline, rounded and truncate or very 

 slightly heart-shaped at the base, rounded 

 above into a very small acuminate point; 

 margin entire below, then undulate or pro- 

 vided with two or three low, rounded lobes 

 which are separated by shallow rounded 

 sinuses; triple-nerved from the base of the 

 blade, the central or midrib slightly the stronger, 

 nearly straight, provided above with about 



« Lesquereux, Leo, The Tertiary flora: 17. S. Geol. Survey Terr. 

 Eept., vol. 7, pi. 47, fig. 2, 1878. 



six or seven pairs of strong, very irregular, 

 remote, and alternate secondaries, of which the 

 lower one is often forked ; the secondaries curv- 

 ing very near the margin and each joining the 

 one next above or running along just inside the 

 margin and fading out; lateral ribs arising at 

 the base of the blade at an angle of about 50°, 

 running nearly straight to the margin, just 

 inside which they apparently curve inward and 

 join the lower pair of secondaries, each with 

 six or eight secondary branches on the lower 

 side which are approximately at right angles 

 to the midrib, somewhat curved upward, often 

 forked, each curving near the margin and form- 

 ing by union with the next higher one a series 

 of large bows; nervilles thin, percurrent, and 

 broken. 



This form is represented in the collection by 

 several well-preserved leaves, four of which are 

 figured. There is considerable range in size, 

 the smallest (fig. 3) being about 6.5 centimeters 

 long and 4 centimeters wide and the largest 

 (fig. 1) about 10 centimeters long and 7 centi- 

 meters wide. The leaf shown in figure 9 is 

 9.5 centimeters long and 6 centimeters wide. 

 The configuration of the base is shown in 

 figures 1 and 2 and is found to be truncate or 

 very slightly heart-shaped. 



This species seems to be related to Dombey- 

 opsis platanoides Lesquereux, 66 from the 

 Bozeman coal field of Montana. It is, how- 

 ever, much longer and narrower, being ovate 

 instead of nearly circular, and, further, is 

 truncate instead of very deeply heart-shaped 

 at the base. The nervation is similar in char- 

 acter in the two species, except that in D. 

 ovata the lateral ribs are at a slightly more 

 acute angle. 



Occurrence: Laramie formation, Erie, Colo. 



SYSTEMATIC POSITION UNCERTAIN OB 

 UNKNOWN. 



Carpites lakesii Knowlton, n. sp. 



Plate XIX, figures 6-8. 



Carpites lakesii Knowlton [nomen nudum], TJ. S. Geol. 

 Survey Bull. 696, p. 135, 1919, 



Fruit evidently hard-shelled, ovoid, rounded 

 at the base, apparently acuminate at the apex, 

 surface not obviously striate or otherwise 

 marked. 



«s Lesquereux, Leo, The Tertiary flora: TJ. S. Geol. Survey Terr 

 Kept., vol. 7, pi. 47, flgs. 1, 2, 1878. 



