LIMNORIA. 229 



these pigmy assailants that have made good a lodgment in 

 them, and which, though not so big as a grain of rice, ply 

 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 ' Charlesworth's 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 



