DESTROYERS OF SUBMERGED WOOD — MURPHY. 215 



XI. — Supplementary Notes on Destroyers of Submerged 

 Wood in Nova Scotia. — By M. Murphy, D. Sc, Pro- 

 vincial Government Engineer, Nova Scotia. 



Mucli has been said and written about the destructive habits of 

 the Limnoria Lignoruni, or " gribble," as it is usually called by 

 the fishermen in Great Britain. It is one of the most destruc- 

 tive creatures, attacking all woodwork below tide mark. Although 

 its ravages have gone on for centuries it was only made known 

 to naturalists by Dr. Leach in 1811. The living specimens wdiich 

 I place before you this evening have been just taken from their 

 burrows in a piece of a submerged pile from a wharf in Halifax 

 Harbor. The piece of pile was sawn off two feet below the sur- 

 face during low water at spring tide. It was immediately placed 

 in a bucket of sea water and brought to my office. On its re- 

 moval from the water the outer soft layers of wood were found 

 to have been burrowed into cells about one quarter of an inch in 

 depth, just deep enough to protect the workers without covering 

 them. I picked them from their burrows with the point of a 

 writing pen, letting them drop into the bottles where you now 

 observe them. You may notice that they are quite active, that 

 they dart forward or backward with equal swiftness and that 

 they are capable of moving rapidly in the water. 



I tried to get them photographed in the water, but without 

 success. Fig. 1, on the following page, is reproduced from a 

 drawing by Prof. J. Smith. Fig. 2 is from a photograph by Not- 

 man. Their length is 4.3 m.m. breadth, 1.6 m.m. ; color in water, 

 light greyish. They are no doubt identical with the Lim7ioria 

 Lignoritm, White, and are the same species of crustacean as that 

 first brought prominently into notice by the celebrated Robert 

 Stephenson, who found it rapidly destroying the wood work at 

 the Bell Rock light-house erected by him on the coast of Scot- 

 land. Unlike the Teredo, this creature is vegetarian and lives 

 on the wood which it excavates, so that its boring operations, 

 as remarked by Dr. Baird, provide it with both food and shelter 



