CONTENTS. XVil 
CHAPTER VIII. 
PAGE 
Upper Formations of the Old Red Sandstone. — Room enough 
for each and to spare. — Middle, or Cornstone Formation. — 
The Cephalaspis its most characteristic Organism. — Descrip- 
tion. — The Den of Balruddery richer in the Fossils of this 
middle Formation than any other Locality yet discovered. — 
Various Contemporaries of the Cephalaspis. — Vegetable Im- 
pressions. — Gigantic Crustacean. — Seraphim. — Ichthyodo- 
rulites. — Sketch of the Geology of Forfarshire. —Its older 
Deposits of the Cornstone Formation. —The Quarries of 
Carmylie. — Their Vegetable and Animal Remains. — The Up- 
per Formation. — Wide Extent of the Fauna and Flora of the 
earlier Formations. — Probable Cause, = ; . 125-150 
CHAPTER IX. 
Fossils of the Upper Old Red Sandstone much more imperfect- 
ly preserved than those of the Lower. — The Causes obvious. 
— Difference between the two Groups, which first strikes the 
Observer, a difference in size. — The Holoptychius a character- 
istic Ichthyolite of the Formation. — Description of its huge 
Scales. — Of its Occipital Bones, Fins, Teeth, and general Ap- 
pearance. — Contemporaries of the Holoptychius. — Sponge-like 
Bodies. — Plates resembling those of the Sturgeun. — Teeth of 
various forms, but all evidently the teeth of fishes. — Lime- 
stone Band and its probable Origin. — Fossils of the Yellow 
Sandstone. — the Pterichthys of Dura Den. — Member of a Fam- 
b* 
