AMERICAN TRIASSIC NEOCALAMITES 
EDWARD W. BERRY 
(WITH PLATE XVII AND ONE FIGURE) 
One of the most dogmatic statements of geology and pale- 
ontology refers to the almost complete change in the character of 
the floras in passing from the Paleozoic to the Mesozoic. This is a 
venerable dogma handed down from generation to generation until 
it has become almost axiomatic. Nevertheless, like most dogmas 
both scientific and otherwise, it was originally based upon lack of 
knowledge and its chief attribute is its unsoundness. A second 
misconception of a narrower kind is the current belief that the 
rocks of the Richmond coal-field in Virginia are of Keuper age. 
This latter seems to be based upon Stur’s comparison (7) with the 
Lunzer Lettenkohl flora of Austria, and upon the somewhat naive 
reasoning of SHALER (6) that since the continued flora, whose 
affinities were early recognized, is unmistakably Rhaetic in its 
facies, it therefore is not of Rhaetic age, since it must have taken 
it untold years to spread over the world. This is an extreme appli- 
cation of HuxLEy’s principle of homotaxis, which is entirely unwat- 
ranted, and one which will be referred to again. 
With increasing knowledge it has become obvious that one of 
the main reasons for the floral break at the close of the Paleozoic 
is conditioned by the unfavorable character of the early triassic 
sedimentation for preserving plant fossils. Among the forms which 
pass the magic boundary are Glossopteris, a probable pteridosperm, 
as WHITE (Q) and others have pointed out; Yuccites, Noeggerathiop- 
sis, Krannera, Eolirion, and Cardiocarpon, and possibly other more 
or less indefinite fossils may represent the Cordaitales in the older 
Mesozoic, as ZEILLER (12) has recently suggested. Sigillaria is rep- 
resented by the form which was christened Pleuromeia by CORDA. 
A number of genera of cycadophytes are already differentiated 
in the late Paleozoic, and it has long been evident that, in spite 
of the contrary tradition, the triassic Equisetales are more like their 
paleozoic than their existing representatives. 
Botanical Gazette, vol. 53] [174 
