FOSSIL CYCADEAN TRUNKS FROM WYOMING 259 



or injured, all the organs have this uniform black or brown 

 color. It is, however, fortunate that while this interferes se- 

 riously with an ordinary macroscopic examination, the applica- 

 tion of a lens removes the obscurity to a considerable degree, 

 and in photographing the specimens it is observed that the dark 

 surfaces come out almost as clearly as the light or variegated 

 ones. 



Besides the lime incrustations on the under surface there was 

 usually a coating of lichens on the surface which lay uppermost, 

 and this, where it existed, was quite as fatal to an examination of 

 the parts thus concealed as the coating of lime. This, though 

 somewhat more difficult to remove, yields to a strong alkali 

 which has no effect upon the underlying structures. 



The cleaning of the specimens by both the processes em- 

 ployed was undertaken as soon as possible after the collection 

 had been unpacked and I commenced the systematic study of 

 the trunks almost at once, thoroughly noting and recording the 

 characters and peculiarities of every specimen and of all parts 

 of each, and by the end of May, 1899, ■'■ ^^^ completed this 

 part of the work. I have compiled tables of the characters 

 and the subdivisions into specific groups has been based mainly 

 upon such characters. Notwithstanding considerable sameness 

 among these characters it is possible to classify them, and there 

 seems no doubt that could their foliage and reproductive organs 

 be known the cycadean flora of the Jurassic of Wyoming would 

 be represented by a considerable number of species if not of 

 genera, although it would be rash to assert that the lines would 

 be drawn in all cases where we must draw them here. 



The most marked feature that struck me on first casual in- 

 spection of these trunks, aside from their relatively small size, 

 light color, and soft calcareous structure, was the frequency of 

 a sort of smooth, to the naked eye, structureless, dull, uniform, 

 covering: that invests their outer surfaces and cuts off the view 

 of the normal organs of the armor. A closer examination re- 

 vealed the fact that this was not an occasional condition, but the 

 normal state of these cycads, and that the cases in which this 

 outer coating is wanting represent the abnormal state. It further 

 became clear that there really are no cases in which it is naturally 



