154 



LARAMIK FLORA OF THE DENVER BASIN. 



ingly like certain of the leaves of C. americana 

 Linn6. In C. americana the lowest pair of 

 secondaries arises at the extreme lower limit 

 of the blade outside the parenchyma, and as 

 they are of the same strength as the midrib the 

 leaf appears triple-nerved. In the fossil leaf 

 the lowest pair of secondaries arises in the same 

 maimer, but they are not quite so strong as the 

 midrib, tlius producing less of the triple-nerved 

 appearance. This lower pair does not seem 

 to be branched on the outside, as Ln the living 

 C. americana, but the leaf is preserved on a 

 coarse-grained sandstone; none of tlie finer 

 nervation can be made out. The first pair of 

 prominent secondaries above the base is about 

 in the middle of the leaf. 



Occurrence: Laramie formation, Mount Car- 

 bon, Morrison, Colo., sandstone near coal seam, 

 collected by Arthur Lakes, June, 1890. 



Rhamnus goldianus? Lesquereux. 



Plate XVIII, figures. 



Rhamnus goldiamis Lesquereux, U. S. Geol. and Geog. 

 Survey Terr. Ann. Kept, for 1872, p. 381, 1873; idem 

 for 1873, p. 405, 1874; idem for 1876, p. 517, 1878; 

 Tertiary flora: U. S. Geol. Survey Terr. Kept., vol. 

 7, p. 281, pi. 53, figs. 4-8, 1878. 



The collection from the wooded bluff just 

 south of the station at Marshall, Colo., contains 

 the single fragmentary specimen here figured. 

 It seems to be identical with some of the 

 smaller leaves referred to Rhamnus goldianus, 

 but the base and all the sides, except a minute 

 portion, are lacking, and the identification can 

 not be positive. It is a Denver species and has 

 not before been reported from the Laramie. 



Occurrence: Laramie formation, Marshall, 

 Colo., wooded bluff just south of station and the 

 highest point in the section, collected by A. C. 

 Peale. Denver formation, Golden, Colo. 



Rhamnus salicifolius Lesquereux. 



Plate XV, figure 4; Plate XIX, figure 2b. 



Rhamnus salicifolius Lesquereux, Am. Jour. Sci., 2d ser., 

 vol. 46, p. 206, 1868; U. S. Geol. and Geog. Survey 

 Terr. Ann. Rcpt. for 1869 [reprint, 1873], p. 196; idem 

 for 1872, p. 400, 1873; idem for 1873, p. 382, 1874; 

 idem for 1876, p. 517, 1878; Tertiary flora: U. S. 

 Geol. Survey Terr. Kept., vol. 7, p. 282, pi. 53, figs. 

 9, 10, 1878. 

 Kno.vlton, U. S. Geol. Survey Bull. 163, p. 70, 1900. 



This species was first named from specimens 

 obtained in the Marshall coal mine, Boulder 



County, Colo. The type specimen is the 

 original of figure 9, Plate LIII, of the "Tertiary 

 flora" and is No. 446 of the United States 

 National Museum collection, though unfor- 

 tunately it can not be found at present. There 

 is in its place another specimen Nx-ith the same 

 number which may have been the counterpart 

 of the one figured, although, as it is very frag- 

 mentary, it is impossible to be certain of this. 

 It is exactly like Lesquereux's figure 9 in its 

 characters, at least so far as can be made out, 

 and is preserved in the whitish sandstone 

 characteristic of the locality. 



The other figured type ("Tertiary flora," PI. 

 LIII, fig. 10) is said by Lesquereux to have 

 come from Black Buttes, Wyo., where it was 

 obtained by Meek,^^ but as the United States 

 National Museum catalogue of fossil plants 

 made up by Lesquereux does not record the 

 species from Black Buttes, this is probably an 

 error. As the original type of this figure can 

 not be found among specimens of this species 

 from any other locality, it must be ignored until 

 it is found or is again collected from the local- 

 ity mentioned. 



The United States National Museum cata- 

 logue records a specimen from Golden, Colo., 

 which is evidently the one referred to by 

 Lesquereux in the Hayden report for 1872, 

 page 382. It is No. 837a and is preserved on 

 the same stone with Salix Integra Goppert (No. 

 837). The matrix is a hard, fine-grained 

 whitish sandstone, not unlike that from Mar- 

 shall, and undoubtedly belongs to the true 

 Laramie. 



A specimen of Rhammus salicifolius is also 

 recorded from the roof of a coal mine on Sand 

 Creek, Colo. Tliis example (No. 935) bears the 

 imprint of two leaves which are much larger 

 than the figured specimens, being 11 or 12 

 centimeters long and 4 or 5 centimeters vdde, 

 whereas the largest type as figured is 9.5 centi- 

 meters long and only 2 centimeters wide. It is 

 possible that this should be referred to a new 

 species. 



The material from Cowan station contains 

 several specimens that appear to belong to this 

 species, especiall}^ the one shown in figure 4, 

 Plate XV. Tills is indistinguishable from the 

 type specimen (Lesquereux's fig. 9), from 

 Marshall. 



« U. S. Geol. and Geog. Survey Terr. Ann. Kept, for 1872, p. 400, 1873. 



