PTERIID. 67 
VOLSELLA BARBATA, Linné (= Mytilus barbatus, Linné). 
Distinctive in the byssus, which resembles a bundle of fine 
tow. 
Minehead. Uncommon ! 
Occasionally washed ashore between Brean and Burnham ! 
PTERIIDZ. 
PINNA FRAGILIS, Pennant (= Pinna rudis, Linné). 
The “fan mussel” is one of our largest native shells, some- 
times fifteen inches long and eight inches in breadth. I found 
a single specimen of moderate size amongst the débris on the 
foreshore beyond Birnbeck Cove, Weston-super- Mare, in June, 
1910. 
OSTREIDZ. 
OsTREA EDULIS, Linné. 
The common oyster. It has been found in the raised beach 
at Woodsprings Hill, Weston, and Mr. Corder has notitied its 
presence in the Burtle Beds at Perry Green, Wembdon. The 
dead shells, often bored by a species of sponge (Cliona), are 
frequent throughout the coast. Some more or less cylindrical 
forms which have been observed near Minehead come near to 
the variety deformis, Lamarck. 
PEC TINID 4. 
PECTEN MAXIMUS, Linné. 
The “ grand-pélerine ” or “ palourde ” of the fish markets of 
Northern France. Jeffreys remarks of it: “If the oyster is 
the king of the mollusks, this has a just claim to the rank and 
title of prince.” 
Coast between Brean and Berrow. Rare! 
PECTEN PUSIO, Linné. 
An odd valve on the shore at the extremity of Brean Down ! 
PECTEN VARIUS, Linné. 
Not common. A form of this species was at one time given 
specific rank under the name of P. niveus; Macgillivray. 
Gwyn Jeftreys wrote: “I believe this varietal difference arises 
from habitat. The strong and few-ribbed P. varius lives on 
oyster-banks and rough ground on an exposed coast; while 
