86 
true nature, but I had a fucoid in my possession found by 
Mr. Grindlay in the drift near Laxey. 
As Mr. Lesguereux’s specimen so much resembles the one 
found at Laxey I shall give his description at length. 
“ Psilophytum cornutum , sp. nov. Plate 1 , fig. 1 . 
“Stem thick, dichotomous, divisions variable in distance, 
the terminal ones short, pointed nearly equal in size and 
length, surface slightly rugose and irregularly striate. 
“ The branches in the lower part are thick comparatively 
to their length, three or four millemetres, irregularly striate 
when decorticated, or merely punctuate upon the thin bark, 
with small projecting dots resembling the basilar remains 
of scales or small decayed leaves; lateral branches short, 
narrowed to a sharp point ; the upper or terminal ones about 
equal in length, appearing like a pair of pointed horns/'’ 
The species is only comparable to some of the fragments 
not specified but figured by Prof. J. W. Dawson (Geol. 
Survey of Canada, Fossil Plants of the Devonian and Upper 
Silurian formations, figs. 243, 244. The author remarks 
“that these fragments are probably originating in the Upper 
Silurian of Gasp6 ; that as they are found in the lower part 
of the limestone which underlies the Devonian Gaspe Sand- 
stone and become more abundant in the upper beds, this 
suffices to indicate the existence of the neighbouring land, 
probably composed of Silurian rocks and supporting 
vegetation.” 
From the preservation of its branches even to the small- 
est subdivisions, the specimens here represent part of a 
plant embedded in the place of its growth. The matrice is 
a piece of very hard calcareous shale seven to eight milli- 
metres thick, bearing on one side irregular undulations like 
ripple marks, without any trace of organic remains, and on 
the other the fragments of plants as figured here. The 
branch in ( a ) represents a different species, and indeed a 
marine or rather a brackish plant, closely related to the 
