Devonian Era in Ohio Basin. — Claypole. 343 
that they were coniferous in their nature and the date of the 
conifers has accordingly been carried back to the earlier part 
of the Devonian era. But it seems on the whole, much more 
probable that they really belonged to the extinct family of the 
Cordaitese. No trace of any foliage resembling that of the 
conifers has ever been found in the same strata with the trunks ; 
whereas the broad strap-like leaves of Cordaites are of fre- 
quent occurrence. Solms Laubach refers Dadoxylon to Arau- 
carioxylon, and Araucarioxylon is now known to be the wood of 
Cordaites, so that the probability becomes almost a certainty 
that the fine leaved pines and firs must be omitted from De- 
vonia and the broad, thin foliage of the now vanished Cordaites 
must be substituted. When some fortunate geologist succeeds 
in finding the characteristic fruit of this family all doubt will 
be removed. I have similar leaves from the Cleveland shale. 
indicating the existence of like species on that horizon. 
Beyond the minute Sporangites already mentioned, the 
Marcellus has yielded almost no recognizable vegetable re- 
mains and the same is, in general, true of the Devonian strata 
below it in the east. In the Hamilton there are stronger indi- 
cations of both marine and terrestrial vegetation,* but even 
here the list is not long. Lepidodendron was represented by 
its earliest known species, L. primaevum from Huntington. 
Pennsylvania, described in the report of the First Survey 
Sigillaria halli is probably an error, the genus being of late- 
origin, at least in the United States. Dawson's Psilophyton 
has been reported from New York. Traces of the broad, flat 
leaves of Cordaites are occasionally met with and a few doubt- 
ful and broken fern-fronds and a Calamite (Bornia transi- 
tionis) nearly complete the list of terrestrial species, setting- 
aside indistinct and indescribable fragments. The fossil wood 
of Eighteen-mile creek in New York belongs with that of the 
Ohio shale. This has already been discussed and Rhachiop- 
teris, Syringoxylon and Psaronius are probably the stems of 
some of the other plants bearing other names. 
Nor has the Hamilton been very productive of seaweed-. 
The ambiguous form Ptilophyton, or Lycopodites, if belonging 
in this part of the kingdom at all, is the best preserved fossil of 
* The works of Si k William Dawson and Prof. L.ESQUBRKUX are referred 
to for details. 
