FOREST MARBLE SERIES. 
339 
Some of the shelly limestones are mainly composed of Oyster shells, 
while layers largely made up of Rhynchonella, Terebratula, and 
other Brachiopods are met with. Occasionally we find thin layers 
crowded with minute Gasteropods. Insects have only been very 
rarely noticed, although the proximity of land is indicated by 
the common occurrence of lignite, by worm-burrows and the 
tracks of invertebrate animals. Some masses of lignite are bored 
by Pholas and Lithodomus. Saurian remains are but rarely 
met with; but bones of Cetiosaurus, &c. have been obtained. 
Fish-remains in the form of palatal teeth are abundant, the 
more common forms belonging to Strophodus. Among the 
Cephalopoda, Ammonites discus (Fig. 119, p. 432) and one species of 
Nautilus have been obtained, though rarely. The Gasteropoda 
are represented by Actceonina, Monodonta, Nerita, Trochus, 
Turbo, &c., but they seldom occur in profusion. Polyzoa are by 
no means rare. The Crustacea include the old Crab Palceinachus, 
and a number of Ostracoda. Annelida are met with here and 
there. Of Echinodermata, Apiocrinus, Acrosalenia, and Cidaris 
are most frequentty found. Corals and Sponges are rare ; 
Foraminifera are fairly abundant in some localities, and will 
probably be found in most places when pains are taken to look 
for them. There are however few species peculiar to the Forest 
Marble, and of the characteristic and common forms none are 
confined to the strata. 
FOREST MARBLE (BRADFORDIAN) FOSSILS 
FIG. 94. FIG. 95. 
FIG. 94. Pecten annulatus, Sow. . 
,, 95. Ostrea Sowerbyi, Lye. f. 
,, 96. Terebratula coarctata, Park. X 2. 
97. Waldheimia digona, Sow. X 2. 
,, 98. Apiocrinus Parkinsoni, Schloth. |. 
Y 2 
