293 
is somewhat different from that given by Professor Uhler. Pro- 
fessor Fontaine, in his laudable desire to do the maximum honor 
to the original discoverer, created a new genus of these forms 
and called them 7ysonia Marylandica. As it turns out he would 
have accomplished his object much better had he given Tyson’s 
name to the species instead of to the genus, since the latter can- 
not stand, as these forms obviously belong to the genus Cycadeo- 
idea of Buckland, which was indeed recognized by Professor Fon- 
taine, when, in a paper to the American Journal of Science,* in 
1879, he used the name « Cycadoidea” in referring to these very 
Specimens. At the same time, by the laws of nomenclature now 
So rigidly enforced, the species cannot be changed, and the name» 
of Tyson drops out entirely. 
The object of the present paper is to record the recent discov- 
ery and collection by Mr. Arthur Bibbins, Curator of the Museum of 
the Woman’s College, Baltimore, of noless than thirty-five additional 
specimens of cycadean trunks and parts of trunks from the same 
general region as that in which Tyson’s specimens were obtained. 
This I regard as one of the most important events in the history 
of palzontology in America, as it brings together such a body of 
facts relative to the cycadean vegetation of the Lower Cretaceous 
in Maryland that it will now be possible to give something like a 
complete history of that type of plants. 
The specimens are all good, many of them extraordinarily 
fine, Nearly half of them are so complete that they may correctly, 
be called trunks, and show nearly or quite all that was ever 
Present; although often much distorted by pressure, and more or _ 
less flattened either laterally or vertically. Many of the remain- 
ing fragments show fully half the trunk, and have the advantage 
of €xposing, on the broken side, the inner parts, the medullary 
axis, woody zones, and sections through the cortical portions. In. 
Several cases the scars produced by the separation of the medul- 
lary axis from the outer parts are very distinctly shown, and in 
one specimen we have a true Cycadomye/on, to the side of which 
the exterior portion of the trunk is attached for some distance, 
thus demonstrating for the first time the true nature of Cycado- 
myelon. Ina number of the specimens the “crow’s nest”’ is dis- 
* TIL, 17: 157. 
