THE AVONIAN OF THE AVON GORGE 
165 
The sockets are crenulated. 
In the pedicle valve, dental plates are well-developed. 
Note : — In the genotype, Rhynchondla congregata of the Devonian, the 
two portions of the hinge plate are not in contact along the middle line, but, 
in CamarotcecMa rnitcJieldeanensis, these two portions are united anteriorly, 
although they are separated by a gap near the beak. 
The Terebratulids 
Dielasma. 
Terebratuliform, elongate-oval, smooth shells with perforated 
beak. 
Shell structure punctate. 
Internal loop. 
Strong dental plates. 
This genus is very rare in the South-Western Province ; it 
is at once distinguished from Seminula by the possession of 
an internal loop and a punctate shell. 
Figures: Dav. Plate I. 
[Note. — The figures of the pedicle valve of Daviesiella afl:. comoides and of 
the brachial valve of CamarotcecMa mitcheldeanensis are reproduced 
from Quart. Journ. Geol. Soc., vol. 61, pp. 295 and 302.] 
