[MATTHEW] CLIMATIC ZONES IN DEVONIAN TIME 131 
to underlying Silurian limestone which thus exactly fixes the time 
of the appearance of the flora in the Gaspé district, or the light they 
shed on some phases of the peculiar vegetation of the Age. 
To take up this table in detail one may say that the Lower Devonian 
of Gaspé seems to indicate two phases of vegetation, which are primi- 
tive in that both appear to show, judging from Sir William’s descriptions, 
traces of a marine origin. The species Prototaxites Logani which that 
author thought to be a land plant, Mr. Wm. Carruthers asserted to 
be a seaweed, and two other species (which however belong to the 
Middle Devonian) Nematoxylon crassum and N. tenue, Prof. D. P. 
Penhallow has claimed to be algoid in their structure. 
Another group of the Lower Devonian of Gaspé, appear to the 
writer to represent the Maritime forms of a modern flora these are 
Psilophyton robustius, Cordaites angustifolia (?) and Arthrostigma gracile. 
Of the first of these it was suggested by Sir William that the trunks 
may have stood in water,* and we have found a strong resemblance 
between its fruiting branches and the fruiting stems of an undescribed 
Silurian plant of southern New Brunswick. The second species Sir 
William referred only tentatively to Cordaites; it is only known from 
its leaves, and these Sir William compared with those of Zosterat. In 
this plant also we have a form which in the way it was entombed in 
the shales, forcibly recalls the attitude and appearance of the vegetative 
part of the Silurian plant above referred to. Finally the Arthrostigma 
gracile, Dn. is congeneric with another Silurian plant which occurs in 
close association with that above described. 
Setting aside the ubiquitous Psilophyton princeps, (and Didymo- 
phyllum reniforme, which may be a rhizome of a Psilophyton or a 
Lepidodendron), the plants of the Lower Devonian of Gaspé appear 
to be a Maritime grouping. 
One might surmise that the plants of the Middle Devonian of 
Gaspé present two ecological groupings. There are the Maritime 
types, C. angustifolia and Arthrostigma gracile, which still retain 
their place in the Devonian sandstones of Gaspé; and to these are now 
added Asterocalamites scrobiculatus v. inornatus Dn. and Annularia 
laxa, Dn., which however may have had fresh water at their roots. 
But Asterocalamites like Psilophyton, seems to have had a wide range 
of habitat. 
The other grouping of plants in the Middle Devonian of Gaspé 
includes the two species of Lepidodendroidea, and the Rachiopteris, 
*Fossil Plants of the Devonian and Upper Silurian, p. 40. 
fIbid. p. 44, 106. 
