ROBERTS — DISTRIBUTION OF CEPHALASPIS AND PTERASPIS. 107 
stone interstratified, which must not be confounded with the trae 
Old Red cornstone which is quarried and tunnelled into beyond this 
quarry — and I have lately met with some bits of fish-armour, with 
cunningly convoluted striae, fragments of a related though, as yet, 
undescribed genus. These also occur in a brown-red coarse grit, at the 
Wall Hills, near Ledbury, though higher in stratigraphical position. 
I have said that through the Whitbatch portal we enter a very 
fine field of research, but our route must be advisedly taken ; and I do 
not recommend another halt in our march until we have left Down- 
ton Hall and its woods behind us, and are looking down from the high 
grounds of Hayton, upon the beautiful dale of the Corve. If we 
trace northward from Upper Hayton the lines of cornstone in out- 
crop parallel to the course of the Dale, we shall come to some notable 
exposures. 
At some points, Hayton's Bent, for example, they are cupriferous, 
though the poorness of the ore obtained, (a carbonate), has ;)4elded 
but little copper, and failure has attended the works. And at another 
spot, near the farm-buildings of DoAvnton Hall, they have yielded an 
ore of lead, in the well-known form of cubic galena. 
But it is for fishes we are searcliing, not metals. There is a small 
quarry in a field at the top of Hayton, which one would think a 
terrible place from its being called the "Devil's mouth," but there 
is nothing alarming about its appearance, nor has it any strange 
connections that I could see, save its treasures of Cephalaspid fish. 
I think I never saw Ptemspis Lloydii of equal size to those I have 
taken in this quarry, though I could meet with no other species. 
The stone is here a fine-grained light-coloured sand-rock, inter- 
stratified with true cornstone. Two miles east of this place, in the 
Upper Comstones of Hopton Cangeford, the monarch of the Cepha- 
laspides in point of size, the great G. asterolfqns, was found by Dr. 
Harley. More of this noble fellow when we mount up to him in 
time, and ascending order of beds. 
On the same horizon, and yielding more or less evidence of their 
former life are the comstones of Hall's Barn, near Kidderminster, 
and of Cradley, near Malvern. In both places I have found frag- 
ments of Cephalaspis and Pteraspis in abundance ; but I need hardly 
remind the collecting geologist that good scutes are of very unfrequent 
occurrence; the majority of specimens having been laid with the breccia- 
like gravel, whose weight and unequal pressure were enough, even if 
motionless and undisturbed by currents, to have broken up the shell- 
Hke plates. And in fact such an amount of grinding did actually 
take place among the shallows and pebble-reaches of the Old Red 
lagoons, that more than one layer of coarse grit lying above the 
lower cornstone is seen by a lens to be crowded with blue and purple 
atoms of fish-shell, the triturated remains of many a good Pteraspis. 
Steering north, with a slight easterly inclination, from the Hayton 
quarry, we shall find several breakages into the lower comstones, 
near the apex of the ridge, at Sutton and Bouldon and Tugford. 
Pteraspidean plates are to be found at each of these places, and a halt 
