DEVONTAN AND, OLD RED? PERIOD. ey) 
GENERALISED SECTION OF THE DEVONIAN ROCKS OF 
NortH AMERICA. 
Fig. 76. 
Z, = 
es m ,° . 
s Pin aes es oe Ses fy Seas eee Catskill Group. 
(oe) : ne ie < = ang fy te =e 
= Stic hate ta ke, ee e « --} 
~ as = a » e . 
fan SSE Se 
e SSS 
= _————————————————— et rel Chemung Group. 
oa _—— 
=) SSIS eS Se OM ae a ee ee 
SA Se Se ea ea CE UN | 
Ree et eee Portage Group. 
x - = te o = © & i ear = 
Z, 
= 
a Hamilton Group. 
= 
x 
A 
co 
= 
a J 
S| Corniferous Limestone. 
= 
= 
De iol) GS 10)).6/( 0.8 jo.6\---— Schoharie Grit. 
BS -: Serre 
= 7, ae ae Spe ee inte | Ee : Wee 
Z g acer eirte otae e Cauda-Galli Grit. 
= A Oriskany Sandstone. 
Lower Helderberg. 
also yielded traces of many other plants (such as Annwlaria, 
A sterophyllites, Cardiocarpon, &c.), which acquire a greater pre- 
dominance in the Carboniferous period, and which will be 
spoken of in discussing the structure of the plants of the Coal- 
measures. Upon the whole, the one plant which may be con- 
sidered as specially characteristic of the Devonian (though not 
confined to this series) is the Pszophyton (fig. 77) of Dr Daw- 
son. These singular plants have slender branching stems, 
with sparse needle-shaped leaves, the young stems being at 
first coiled up, crosier-fashion, like the young fronds of ferns, 
whilst the old branches carry numerous spore-cases. The 
