TRANSACTIONS OF THE SECTIONS. 105 
obscure vegetable forms, Parka decipiens of Lyell, Plerygotus, and Cephalaspis, he 
was now enabled to add several new and gigantic forms of Fucoids, a Cyclopteris, and 
a Lepidodendroid stem, which was clearly of terrestrial origin. To the Fauna he has 
added gigantic Foralites and Scolites, or annelid burrows and annelid tracks, and an 
organism which appeared to be the remains of an annelid itself. © There had also been 
discovered several new portions of Pterygotus, which rendered the true structure of 
that gigantic crustacean much more apparent ; and he had also been enabled to de- 
scribe and figure two new crustaceans under the names of Kampecaris and Stylonurus, 
the latter closely related in structure to Eurypterus, and approaching the forms of 
those found in the Lanarkshire strata. To Cephalaspis, of which little more was 
known than the head and bony ring-plates of the body, he had now to add a well- 
marked corneous eye-capsule, a pair of pectoral fins (or rather swimming paddles), a 
subdorsal fin, and the true form of the large heterocercal tail;—so that, instead of 
figuring this much-caricatured fish as had hitherto been the case, as a saddler’s knife 
for the head, and a parsnip with a few radicles for the body, we could now restore it 
as a legitimate and elegant fish, much resembling in general contour the armed bull- 
head or Aspidophorus of our present shores. There had also been discovered a vast 
number of fin-spines or Ichthyodorulites, which were yet undescribed; and a small 
fish with fin spines and shagreen-like scales, to which he had given the name of Icti- 
nocephalus granulatus, in allusion to its kite-shaped head and shagreen-covered body. 
For the discovery and preservation of these new fossil forms, palzontologists were 
mainly indebted to James Powrie, Esq., of Reswallie, Forfar, and to Mr. Simon, sur- 
geon, Lismahagow. 
On the Relations of the Metamorphic and Older Paleozoie Rocks in Scot- 
land. By D. Pace, F.G.S. 
As was well known, a large development of Silurian strata occurred in the south of 
Scotland, dipping northward under the Old Red Sandstone, which in turn underlaid 
the coal-fields of the Forth and Ciyde. On the northern side of the coal-basin, the 
Old Red dipped southward, again underlying the coal-measures ; but between the 
Old Red and the Grampians, no true representative of the Silurian system had as yet 
been detected. What, then, were the relations of these rocks? He had made many 
sections during the last two summers, and found that everywhere, from Stonehaven 
on the east to Bute on the west, a thick mass of trappean conglomerate succeeded the 
crystalline schists, that this was succeeded by the fissile grey strata of Perth and 
Forfar, containing Pterygotus and Cephalaspis, these by the ‘Great Pebbly Conglo- 
merate,” and then the middle Old Red with Holoptychius, and the upper yellow 
beds with Holoptychius and Pterichthys. The Pterygotan beds, though evidently 
approaching the upper Silurians of Lanarkshire in fossil characters, were still the 
basis of the Old Red; and if Silurian strata did exist on the southern slopes of the 
Grampians, geologists must seek for them either in the trap conglomerate and grits 
below, or in the clay-slates and mica-schists which might be the metamorphosed 
equivalents of the Silurians of Peebles, Roxburgh, and Dumfriesshire. Two con- 
clusions thus presented themselves: either the physical geography of the north had 
been such during the Silurian era, as not to admit the deposition of strata; or having 
been deposited, as in the south, they had been subsequently metamorphosed and all 
traces of organic life been obliterated in their crystalline structure. Whichever view 
might be adopted, we had in the mean time no fossil evidence of Silurian strata on 
the southern flanks of the Grampians, though in the south of Scotland, and on the 
south side of the great basin of the Clyde and Forth, a vast development of lower, 
middle and upper Silurians had been traced and pretty closely examined, Grouping, 
therefore, the older rocks of Scotland according to the present state of our inform~ 
ation, we had something like the following succession :— 
PERMIAN. ..+...+e. Breccia conglomerates of Annandale. 
Upper and ‘lrue Coal Measures, 
Millstone Grit (feebly indicated). 
Carboniferous Limestone (Marine). 
Lower Coal Series (Estuarine). 
CARBONIFEROUS... 
