G. li. Wieland — William sonian Tribe. 453 



the study of modes of occurrence and conservation which may 

 direct attention to other regions and localities equally rich in 

 fossil remains. That a freer illustration of the Yorkshire coast 

 fossils would soon have brought out the peculiarities of cast 

 conservation, and would long since have disclosed the chief 

 structural features of the ovulate cones, can scarcely be doubted. 



Ovulate Cone and Cast Characters. — Nothing is more baf- 

 fling in the study of these cones than the capricious manner in 

 which conservation begins and ends, often in the midst of a 

 tissue zone. Thus in the English Williamsonias, save the lost 

 type of Buckland's " Pandanus" figured in the Bridgewater 

 Treatises, the seeds uniformly fail of preservation. Yet in an 

 isolated pone of Cycadeoidean form from the Argonne the large 

 seeds are distinct and even the embryos are at times outlined. 

 But while the seeds so often fail to outline themselves, the 

 conserved sterile interseminal scales are very apt to clearly 

 demark the fruit base and the summit, a caprice of cast and 

 imprint formation also much in evidence in the Oaxacan region. 



The ovulate fruits of the Yorkshire coast as collected in the 

 early days when the naturally weathered-out specimens were to 

 be found in some abundance, are the large forms five to eight 

 centimeters in diameter, and often but not always flattened. 

 Such are shown in the painstaking drawings of Mr. Weber, 

 reproduced in the figs. 7-13, all the result of joint study of 

 details by both writer and artist. 



The striking association of fronds with an abundance of 

 strobili in some of the weathered specimens seemingly broken 

 up at random, appears especially in figs. 9-11. But further 

 considering fruit outlines, a most instructive strobilus is fully 

 illustrated in complete projection by fig. 8 showing the lateral 

 and end views with a median longitudinal section partly restored. 

 As clearly appears from the figure, the bracts enclosed a strik- 

 ingly handsome fruit ; though as partly due to weathering and 

 partly to the lack of uniformity in preservation already spoken 

 of, no surface details actually appear, and one is left to wonder 

 at the weathering-out so nearly on the original outer surface. 

 But contrariwise, certain interior features are unexpectedly 

 clear ; the form of the conical-shaped receptacular axis is 

 sharply outlined, some of the soft tissue even retaining struc- 

 ture, while at the apex conservation again begins in the out- 

 curving mass of interseminal scales, and as sharply ends to form 

 a pyriform cavity more or less filled with the white clayey ma- 

 terial " scarbroite." In fact we can easily see that the entire 

 space occupied by the cavity was in life filled out by the con- 

 tinuation of the zone of slender sterile organs as a closely 

 packed mass, silky or wavy and slightly spreading at the sum- 

 mit. And this is an interesting feature, in its turn aiding us 



