﻿FOLIAGE. 



95 



the apparent position of the cycads, which were, without exception, found eroded 

 out as loose boulders at the old locality. As a result specimen No. 208 was discov- 

 ered nearly or precisely in situ in a sandstone stratum not more than a few feet below 

 the Dakota sandstone and about 125 feet above the Atlantosaurus beds of Marsh. 

 Trunk No. 208 is large, flattened, much worn, and somewhat pear-shaped with 

 the large end basal, the top being wholly broken away and smoothed by either 

 water or more likely aeoliau erosion. It has the following dimensions : 



Height 89 cm. 



Long diameter 47 



Short diameter 34 



Least thickness, or diameter of flattened upper end 19 



Weight, 139.6 kilograms = 308 pounds. 



Of far more interest than its precise stratigraphical position are the structures 

 present. As collected, the trunk bears, laterally or adventitiously, ten or more 

 young leaves, which are marvelously preserved, still folded, and not yet emergent. 

 In the case of six of these the naturally polished transverse sections are in plain 

 view, but were not at once observed. When first examined the trunk was dust- 

 covered, and later, being a huge and otherwise most unpromising specimen, it was 

 not closely scrutinized, its wonderfully preserved leaves finally being found by acci- 

 dent, after leaves had been noted in various other species. None of these leaves 

 have yet been thin-sectioned, but the following descriptions — based solely on trans- 

 verse sections, in part polished naturally, and in part by means of carborundum 

 bricks without removal from the trunk, which remains intact as when collected — 

 fully testify to the beauty of leaf preservation exhibited. (See fig. 51.) 



The second striking fact concerning these adventitious leaves is their isolated 

 distribution laterally among the very old leaf bases, with but little or no indication 

 of their having arisen from lateral buds, such not having been once observed with 

 certainty, in either Cycadeoidea ingens or the closely related C. Jenneyana, although 

 both species are known from many specimens and freely bear the lateral fructifica- 

 tions usually seen in the cycads from the Black Hills. Orientation with reference 

 to the axis of the trunk is 

 nevertheless as regular and 

 exact as in case of leaves in 

 normal apical series; though 

 the lowermost leaf of the 

 young abnormally situated 

 series is borne far down on 

 the trunk and quite isolated 

 from the others, which are 

 mostly scattered over an area 

 of some 10 by 15 cm. The 

 distances of the several young leaves above the base of the trunk, which, as 

 noted before, is 87 cm. high and incomplete, together with the chief features and 

 the dimensions of the several transverse sections of the leaves as arranged accord- 

 ing to their size, are tabulated herewith. The unusual number and vigorous growth 

 of these adventitiously borne leaves may well be accounted for on the theory that 



