116 BALA FOSSILS FOUND IN THE NEIGHBOURHOOD 
Diagrammatic Section, showing General Order of the Sub- 
divisions in the Bala Series. 
B|,c ld 
bs 2.) 33 i 
WENLOCK. CARADOC OR BALA SERIES. 
a—Flaggy beds. 
6—Denbigh grits. 
c—Graptolite shales. 
d—Tarannon shales. 
1—Hirnant grits, limestones, and shales, containing Orthis 
Hirmantensis, O. sagittifera, O. biforata, &c. 
2—Calcareous shales, containing Orthisina ascendens, Meristella, 
Pterinea, Ambonychia, Murchisonia, Echinoderms, &c. 
3—Polyzoa in abundance, especially Phyllopora, Ptilodictya, &c. 
4—Like the last zone, this is composed of fine sandy shales, the 
greater part- being barren; the fossiliferous zone is at 
the top, and contains several species of Trilobites, a few 
Echinoderms and dwarf Polyzoa, small Brachiopods, &c. 
5—This zone represents the Bala crystalline limestone and 
coarse sandy shales, containing Cephalopods, Cystideans, 
Univales, Lingula ovata, Orthis Actonia, O. calligramma, &c. 
6—Sandy shales, containing Asaphus Powist’, Homalonotus, and 
small Brachiopods. 
7—Sandy limestone resting upon an ash bed; the sandy lime- 
stone is full of Orthis vespertilio, and O. spirtferotdes. 
8—Calcareous shales, full of Lepfena, Orthis elegantula, Stropho- 
mena expansa, Beyrichia, and Cythere umbonata. 
9—Sandy or fine shales resting upon an ash bed. The shales 
contain various species of Brachiopods, but the most 
abundant is Orthis alternata, and it is confined to this 
zone. 
e—Dark earthy fossiliferous shales. 
f—Felspathic ash. 
g—Fossiliferous shales. 
