On Cephalaspis magnifica from the Caithness Flagstones. 273 
shows that the genus continued to exist until far on in that 
great epoch of the world’s history. 
But the specimen is of great interest in its bearing on the 
question of the imperfection of the Geological Record which 
a few writers seem even yet to be desirous of minimising. 
It is well-nigh seventy years since the fossil fishes of the 
Old Red Sandstone of the north of Scotland began to be 
assiduously collected,—for Sedgwick and Murchison’s paper, 
in which Caithness ichthyolites were first figured, was pub- 
lished in 1828.1 But the labours of Traill and others in 
Orkney—of Sedgwick and Murchison, of Dick, and of C. W. 
Peach in Caithness—of Hugh Miller, Stables, Malcolmson, 
Duff, Lady Gordon Cumming, and others along the shores of 
the Moray Firth, did not, during these sixty-five years now 
concluded, disclose a single relic of any Cephalaspidian in 
the rocks in question, and people were naturally left to 
believe that no fishes of that family existed in the waters 
in which they were deposited. 
Suddenly and unexpectedly, however, during the past 
summer a Cephalaspis is discovered in the Thurso district, 
and in a quarry which had been worked for paving-stones 
for at least thirty-five years. Only one single specimen, 
too, is found, but it must have had parents, and relatives, 
and ancestors. Where are they ? 
EXPLANATION OF PLATE VII. 
Fig. 1. Cephalaspis magnifica, Traq.; one-third natural size. 
Fig. 2. Tuberculation of the surface at the margin of the orbit; magnified 
3 diameters. 
Fig. 3. Finer tuberculation of the surface; magnified 3 diameters. 
Fig. 4. Pseudo-tessellation of the middle layer of the shield; magnified 2 
diameters. 
10On the Structure and Relations of the Deposits contained between the 
Primary Rocks and the Oolitic Series in the North of Scotland—Trans, Geol. 
Soe. (2), vol. iii., pp. 125-160, plates xiv. -xvii. 
