Name of the Shell. 
Margarita elegantissima, Bean . .|. 
| Lower Glacial. 
| Middle Glacial, 
Cemoria Noachina, Linz.......... adel Hoe 
Calyptrea chinensis, Linn. ...... ec 
Dentalium abyssorum, Sars 
, var. tarentinum 
dentalis? Linn. 
Rhynchonella psittacea, Chemn..|...|--- 
Anomia ephippium, Linn. ..... 
eer eeetesenslsee 
striata, Broce. ....cccsseeese. * 
Ostrea edulis, Linn. ..........0-.+- nee 
Pecten opercularis, Linn..........|... 
islandicus, Miill. ........00+- Au 
—— pusio, Pennant............... acallaoc 
Mytilus edulis, Zinn. ............ * 
Modiola modiolus, Zinn. ......)... 
Pinna pectinata, Linm..........++- * 
Pectunculus glycimeris, Linn....|... 
Arca lactea, Linn.....ccececceceeses a: 
Nucula Cobboldiz, J. Sow. ...... 
Leda limatula, Say 
Centre eee eeseee 
—- myalis, Couthouy 
tents, Mont. tase eeeee eee Pareles 
pernula, Mill. ......c00..0.. Bealls 
PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 
[ Dec. 8, 
Upper Glacial). 
| Bridlington (or 
| Crag. 
* XK 
*: 
~~ OK 
kK OK 
KK Ie OK 
see note at foot 
Living or extinct: 
of list. 
| 
| 
b> 
& 
| 
MM. plicata, Sars. 
Remarks. 
Puncturella Noachina of Forb. & 
Hanl., and of Jeffreys. 
One young specimen from the 
Middle Glacial. 
D. costatum, J. Sow. Two speci- 
mens from the Middle Glacial. 
The costs are as broad as, but 
less prominent than, in the Crag 
shell; but this may be due to 
wear. It is possible that the spe- 
cimens may be only the upper 
portions of D. abyssorum. 
A, squamula of Woodward’s list. 
Common in Middle Glacial, 
Sitka and Norway. 
Lower beds of Red Crag only. 
Middle Glacial of Stevenage, 
Herts, only. 
Very common in Middle Glacial, 
but fragmentary. 
A specimen in Brit. Mus. said to 
be from Bridlington. 
Worldwide. 
M. vulgaris of Woodward’s list. 
Fragments in Cromer Till. 
Very common, but small, in Mid- 
dle Glacial ;-dies out in the up- 
per beds of the Crag. 
The hinge of the Middle-Glacial 
(perfect but small) specimen is 
too worn for certain identifica- 
tion. i 
The Lower- and Middle-Glacial 
and Bridlington specimens show 
a tendency to depart from the 
Crag form in having the pecu- 
lar ornamentation more con- 
fined to the upper and central 
part of the shell. Represented 
by WV. Lyaili on the N.W. coast 
of America. 
Yoldia oblongoides of Woodward's 
British also? [list. 
Three specimens in Brit. Mus., two 
from Postwick, a Crag locality, 
and one from Runton, which 
* (except the forest freshwater 
bed) is Lower Glacial only. 
