108 Beautiful Shells. 
to support the weight of the frond, and thus the 
plant is detached and driven on shore by the waves. 
* And so the forest tall, that groweth 
Underneath the waters clear, 
Does the little woodman mollusk 
Level every year; 
From small causes, great results— 
Teaching you to persevere.” 
RNOCK-BORERS. 
The family Pholade comprises a group of mol- 
lusks, the boring habits of which have long been 
known; they penetrate wood, hard clay, chalk, and 
rocks, and devastate the labours of man; they 
attack the hulls of ships, the piles which form the 
foundations of piers and breakwaters, and they force 
themselves upon our attention by the loss of pro- 
perty, as well as hfe, which results from their 
hidden depredations. Of this family, those belong- 
ing to the genus Pholus may be more especially 
likened to the Edomites of Scripture, because they 
take up their abode in the rock, and hollow out for 
themselves dwellings therein. With a shell as thin 
as paper, and brittle as glass, the wonder is how 
