FONTAINE.] THE EMMONS COLLECTION. 803 
preserved so as to show its original dimensions and form. It was 
evidently unusually small, the height being only 6cm. and the maxi- 
mum width probably 8cm. A portion of the right-hand side is miss- 
ing, so that the entire original width is not shown. The shape was 
approximately broadly elliptical or bulbous. At the top is what seems 
to have been the growing bud. This appears to have been pressed 
down upon the sandy shale, which has preserved the imprint. It is 
merely an imprint, and not, as is commonly the case, the petrifaction 
of the trunk itself. The leaf scars are remarkably distinct, and they 
are rather small, as might be expected from the size of the trunk. 
They are approximately rhombic in form, about 6mm. long and 4mm. 
in height, the longer dimension being transverse to the axis of the 
trunk. They have a raised margin surrounding a depressed rhombic 
space. The upper and lower angles of the scar are more or less 
rounded and the lateral ones drawn out. The form clearly belongs to 
a new species of the group Cycadeoidea. 
inferred. The irregularity in the lower right-hand corner seems to be the result of defective pre- 
servation.” 
The specimen was sent to the University of Virginia, along with the other types requiring to be 
drawn, and came back to Washington with therest. It was very carefully drawn by Mr. F. von Dachen- 
hausen of the Division of Illustrations of the United States Geological Survey, under my immediate 
supervision and with the aid of all the descriptions and figures that had been made of it, including 
Professor Fontaine’s fresh notes and my own, as quoted above. We fully discussed the question of 
orientation, especially in view of the fact that Professor Fontaine, in copying Dr. Emmons’s figures, 
had reversed it, believing that Dr. Emmons had misinterpreted its nature. I have recently had occa- 
sion to examine and minutely describe several hundred specimens of cycadean trunks from the 
Mesozoic deposits of the United States, especially from the Potomac formation of Maryland, the Lower 
Cretaceous of the Black Hills, and the Jurassic of Wyoming (see infra., pp. 382-417). I also visited in 1894 
the principal mouseums of Europe where collections of such trunks exist, notably the British Museum 
at South Kensington and the Geological Museum at Bologna, and I have thus made myself some- 
what familiar with the nature of these objects. I was satisfied at a glance at Emmons'’s figure that 
he was right in regarding the impression as that of a trunk, and so stated early in 1894 (Proc. Biol. 
Soc. Washington, April 9, 1894, Vol. IX, p. 86). 
It is true, as Professor Fontaine remarks, that.such trunks are usually petrifications, having some- 
what their original form and three dimensions, whereas this is only a flat impression similar to 
that which most other kinds of fossil vegetable remains present. Still, there is nothing in this fact 
that precludes the possibility of this representing a trunk. Itis possible that the Triassic cycads 
may ‘have been more succulent and less decidedly woody than those of the later ages. Again, 
the well-known petrified trunks have all been preserved under entirely different conditions. None 
of them occur in coal beds, but all in a more or less sandy matrix. Such is the case in the Black 
Hills, and the fine collection of fossil plants made by Professor Jenney in the Hay Creek coal field, 
at the same horizon as that of the cycads, yielded no fossilized trunks (see Nineteenth Annual 
Report, Part II, pp. 521-946). Any such trunks that may be found in coal beds will, in all probability, 
have the general character of the one now under consideration. 
Special attention was paid to the true direction of the axis. The scars represent the leaf bases, and 
in all cases these have something like a keel on the lowerside. One of the angles of the scar is there- 
fore certain to be on the lower side, and this is one of the safest guides in finding the axis of the 
trunk. The position in which Dr. Emmons placed the specimen is an almost impossible one. It 
makes one series of rows of. scars vertical and the other horizontal, or nearly so, and none of the 
angles aredownward. By turning the bottom of his figure about 30° to the left the conditions of nor- 
mal growth are fairly well satisfied. This is done in the new figure (Pl. XLIII, Fig. 3). The true 
apex was also found, and the spiral rows of scars encircle the trunk in a normal way and cross one 
i 11-preserved forms. 
another as in most other well-p: LF. Ww. 
