214 



SHORTER COXTRIBUTIOXS TO GENERAL GEOLOGY, 1921. 



meters long and 1.5 centimeters wide. The 

 average dimensions of a large number of speci- 

 mens, however, are 6 to 7 centimeters long by 

 1 to 1.3 centimeters wide. 



Leaves thick, with smooth surface. Rachis 

 and midrib stout. Venation more prominent 

 than in the other species but still very faint, 

 with the exception of the secondaries, which 

 though fine are more conspicuous than in the 

 other species. Secondaries forming a wide 

 angle with the midrib, nearly straight for two- 

 thirds of the distance to the margin, where they 

 bend sharply upward and join the secondary 

 next above by a slightly curved arch. As the 

 secondaries are numerous and almost uniformly 

 spaced the venation resembles that of a 

 Eucalyptuft except that the marginal hem is 

 much broader than in that genus. In fact 

 some of the detached leaflets were determined 

 by Ward as forms of Eucah/ptuf<, as also was 

 some of the Mrginia material of this species. 



This species is exceedingly abundant at many 

 localities in the Patapsco formation in Maryland 

 and Mrginiaand is by far the most characteristic 

 species of that formation, although it has not 

 been detected at certain other undoubted 

 Patapsco horizons. Not especially characteris- 

 tic material is abundant along Oak Creek, 

 Wyo., in beds that have been referred to the 

 Fuson formation. This species was also sug- 

 gested by Cockerell -' for some leaves from an 

 unknown geologic hoxizon in southwestern 

 Colorado. I have since examined this material, 

 which is very inconclusive, in my opinion. 

 Cockerell infers that Sapindopsis may be re- 

 lated to Giietum, but I cannot see any warrant 

 for such a supposition. 



This species is an exceedingly variable form 

 in all its details, and as during maceration the 

 most variable apical portion is the last to be 

 destroyed, this variability is emphasized in 

 fragmentary material such as that usually 

 found. When well preserved it furnishes most 

 striking specimens, as may be seen from the 

 specimens reproduced photographically in 

 Plate LV (figs. 2-4). In life its rigid pinnate 

 leaves and strict appearance must have made 

 it a very striking member of the Cheyenne 

 flora. 



The Cheyenne sandstone occurrences of 

 Sapindopsis variabilis are Osage Rock at Bel- 



" Cockerell, T. D. A., Washington Acad. Sci. Jour., vol. 6, p. 110, 1916. 



videre (2217, 2232) ; Stokes Hill (2220) ; Thomp- 

 son Creek near the flume, 2 miles northwest of 

 Belvidere (2221); Champion (Wildcat) Draw, 

 three-fourths mile south of Belvidere (2222); 

 Champion (Wildcat) Draw, right (east) branch, 

 in "Lanphier shale," hah' a mile south of 

 Belvidere (2224, 2228, 2231) ; in shale m a draw 

 1 mile southwest of Belvidere (222.5) ; left bank 

 of middle branch of Champion (Wildcat) Draw 

 (2229) ; shales in draws north of Belvidere 

 (2230) ; first draw west of Champion (Wildcat) 

 Draw (2233). 



Sapindopsis magnifolia Fontaine. 



Plate LV, figure 5; Plate LVI, Plate LVII, figure 2; Plate 

 LIX. figure 3. 



Sapindopds magnifolia Fontaine, U. S. Geol. Survey 



Mon. 15, p. 297, pi. 151, figs. 2, 3; pi. 152, figs. 2, 3; 



pi. 153, fig. 2; pi. 154, figs. 1, 5; pi. 155, fig. 6, 1890; 



in Ward, U. S. Geol. Survey Mon. 48, pp. 481, 482, 



528, 1906. 

 Berry, U. S. Nat. Mus. Proc, vol. 38, p. 642, 1910; 



Maryland Geol. Survey, Lower Cretaceous, p. 471, 



pi. 86; pi. 87, fig. 1; pi. 88, 1911. 

 Aralia dubia Fontaine, U. S. Geol. Survey Mon. 15, p. 



314, pi. 157, figs. 1, 7, 1890. 

 Sapindopsis obtusidolia Fontaine, idem, p. 301, pi. 156, 



fig. 13; pi. 159, figs. ,3-6. 

 Fkophyllum eucaly ptoides Fontaine, idem, p. 294, pi. 164, 



figs. 1, 2; in Ward, U. S. Geol. Survey Mon. 48, p. 



489, 1906. 

 Sapindopsis tenuinervis Fontaine, U. S. Geol. Survey 



Mon. 15, p. 301. pi. 153, fig. 1, 1890; in Ward, 



U. S. Geol. Survey Mon. 48, pp. 489. 528, 1906. 

 Rhus uddeni Lesquereux, U. S. Geol. Survey Mon. 17 



(Flora of the Dakota group), p. 154, pi. 57, fig. 2, 



1892. 

 Knowlton, in Hill, .\m. Jour. Sci.. 3d ser.. vol. .50, 



p. 213, 1895. 



Leaves commonly odd-pinnate, although a 

 few even-pinnate forms occur, of considerable 

 size but somewhat variable. Leaflets three 

 pairs, comparatively large, lanceolate, tapering 

 almost equally toward apex and base, the base 

 inequilateral except in terminal leaflets, pointed, 

 often lacking apical portions, length increasing 

 proximad, averaging about 10 centimeters, 

 longest seen 14 centimeters (estimated), short- 

 est 5 centimeters, width varying from 1.1 to 3.2 

 centimeters, inequilateral, as the outer half of 

 the lamina is broader than the inner half and is 

 markedly decurrent. This feature is least em- 

 phasized in the basal leaves, which may even 

 have a considerable petiole, but becomes in- 

 creasingly pronounced distad, the terminal 

 leaflets often forming a bilobate or trilobate 



