JURASSIC CYCADS FROM WYOMING. 181 



are even approximately complete. The rest are fragments of all sizes, Ijiit 

 many of them very small, the least weighing no more than 5 or 6 grammes. 

 Many of the latter, however, show the internal structure very clearly, and 

 when the time arrives for making a study of them from microscopic 

 preparations these will yield excellent results. 



In view of these last-mentioned considerations, and also in the hope 

 of finding as many pieces complementary to the originally described types 

 as possible, I thought it worth while to make a somewhat careful study 

 of all this material, and I therefore devoted to it a considerable part of my 

 time from September 23 to December 31, 1901. The original types were 

 laid out in a conspicuous position and arranged by species for comparison, 

 and the_later collections were then similarly exposed and first arranged by 

 numbers. Before any satisfactory results could be reached it was found 

 necessary, as in the case of the original collection, to clean the specimens 

 with hj^drochloric acid and remove the incrustation of lime that obscured 

 the structure of the majorit}' of them. This was done simultaneously 

 with their study. At first it seemed that only a very few could be identi- 

 fied with described species on account of their fragmentary character, 

 but prolonged and minute inspection and comparison with the types 

 graduall}' revealed characters that could not otherwise be detected, and 

 finally enabled me to venture a provisional reference in the case of a large 

 number to the species described in the first paper. The question whether 

 the new material contains any additional species beyond the twenty species 

 previously described can not be definiteh' settled, but 1 incline to think 

 that some of the fragments belong to species different from those of the 

 first collection. This, however, is not certain from the scanty material, 

 and I have therefore referred such with doubt to the species that they 

 most closely resemble. It does not seem that any of the complete trunks 

 or large characteristic fragments belong to new species, although some of 

 them possess characters not seen in the original types. This is notably 

 the case with those that I am obliged to refer to species founded on only 

 one or two specimens, but in such cases this was to be expected. 



I shall take up the species in the same order in which they were treated 

 in the first paper and make such additional notes on each as the study of 

 the later material calls for. In view of the probability that the specimens 

 will be one day taken up and subjected to microscopic study from the 



