WARD.) FOSSIL WOOD FROM THE JURASSIC. 417 
7. Cycadella nodosa. 14. Cycadella verrucosa. 
8. Cycadella cirrata. 15. Cycadella jejuna. 
9. Cycadella exogena. 16. Cycadella concinna. 
10. Cycadella ramentosa. 17. Oycadella crepidaria. 
1. Cycadella ferruginea. 18. Cycadella gelida. 
12. Cycadella contracta. 19. Cycadella carbonensis. 
13. Cycadella gravis. 20. Cycadella Knightii. 
The order can scarcely be called a classification, There is, however, 
something in common in the first twelve, viz, their general light 
color and calcareous structure, while the last seven are darker, coarser 
grained, and less calcareous. (C. gravis and C. verrucosa are interme- 
diate in these respects, but the former differs in its high specific 
gravity. These distinctions all relate rather to the mineral than to 
the vegetable character, and although there is always some connec- 
tion between them arising out of differences of structure, still it can 
scarcely be called a systematie grouping. The strictly botanical char- 
acters traverse these more conspicuous ones in such a manner that 
it is impossible to arrange the species according to both, and it was 
considered more satisfactory, upon the whole, not to attempt any finer 
classification until the internal structure can be studied, which should 
be done, and promises most interesting results. 
FOSSIL WOOD FROM THE JURASSIC. 
Fossil wood has been reported from the Jurassic in a number of 
cases, but I am able to illustrate it at the present time from only two 
localities. 
FOSSIL WOOD FROM THE CYCAD BEDS OF WYOMING. 
Accompanying the cycad collection of Professor Knight were three 
pieces of fossil wood, numbered 500.85, 500.86, and 500.87: of the 
Museum of the University of Wyoming. Two of these, Nos. 500.86 
and: 500.87, were placed in the hands of Dr. F. H. Knowlton, who 
offered to work out the internal structure and report the result. One 
of the specimens, No. 500.86, was a small limb somewhat split up and 
splintered, and it proved difficult to obtain from it slides of the proper 
character. ‘The other, No. 500.87, is a thick block of wood and has 
furnished good slides, although the structure is somewhat obscure. 
Enough was learned from the other specimen to indicate that it 
belongs to the same species, and the piece which was not treated, No. 
500.85, is clearly a part of the same stemas No. 500.86. All the 
wood, therefore, probably belongs to the same species. No explana- 
tion has been made of the source of this wood further than that it 
accompanied the cycads and is supposed to have been found with 
them. In fact, it was at first thought possible that they might be 
found to belong to the interior of cycadean trunks. They are, there- 
fore, of course, of the same age as the cycads. 
20 GEOL, PY 2——27 
