LIMNORJA. 
229 
these pigmy assailants that have made good a lodgment in 
them, and which, though not so big as a grain of rice, plv 
their masticatory organs with such assiduity as to have 
reduced great part of the woodwork which constitutes their 
food, into a state resembling honeycomb. One specimen 
was a portion of a three-inch fir- plank nailed to the north 
pier about three years before, which is crumbled away to 
less than an inch in thickness ; in fact, deducting the space 
occupied by the cells which cover both surfaces as closely as 
possible, barely half an inch of solid wood is left ; and 
though its progress is slower in oak, that wood is equally 
liable to be attacked with it. If this creature were easily 
introduced to new stations, it might soon prove as destruc- 
tive to our jetties as the Teredo navalis to those of Holland, 
and induce the necessity of substituting stone for wood 
universally.” 
It has been found at various parts on the coast, as, for 
instance, on the shores of the Firth of Forth, where Dr. 
Coldstream observed it, and made it the subject of an 
excellent memoir. Dr. Moore, in f CharleswortlFs Maga- 
zine of Natural History/ stated that for forty years its in- 
jurious powers had been known in the harbour of Plymouth, 
where it is called “ the gribble.” It has been found on 
