TEREDO NAVALIS IN NOVA SCOTIA — MURPHY. 361 



about one-half inch on the exposed surface per annum, or about 

 one-half as much as at Halifax, and some other places on the 

 Atlantic coast. In 1877 one of the piers of the Victoria bridge, 

 which crosses Bear River near its confluence with Annapolis 

 Basin, toppled over, owing solely to the borings of the Limnoria 

 Lignorum. It had been constructed about 10 or 11 years, and 

 was erected thus : 



1st. Cribs were built of logs, floated to the site of the piers, 

 and there sunk by stone. 



2nd. Around the submerged crib-work a single row of piles 

 was driven at a distance of three feet apart centres. 



3rd. On the rectangular single row of piles the piers were 

 erected, which then, stilt-like, supported the whole weight of 

 superimposed pier and superstructure. 



Many of the piles suffered so much from the attacks of these 

 Crustacea, that several of them floated away with the tide, caus- 

 ing the pier to tilt over and carry the bridge superstructure 

 with it into the stream below. 



At the lowest spring tides known for that year, I visited the low- 

 er trunk of the pier which still remained standing, with the view 

 of having it renewed. Every pile was eaten at the level of low 

 tide to about three inches from the former surface, until its sec- 

 tion became so reduced as not to be able to support the superim- 

 posed weight above. The timber consisted of spruce, hemlock and 

 pine, — the attacks seemed to be just the same on each, irrespect- 

 ive of kind. I would here mention that the same remarks ap- 

 ply to hardwood, such as black maple and oak. 



I will now briefly advert to the animals themselves. 

 Dr. E. H. Von Baumhauer, Commissioner to the Centennial 

 Exhibition from Holland, in papers published in the "Popular 

 Science Monthly" for August and September, 1878, gives, through 

 the translation of Mr. Andrews, the following very full and in- 

 teresting description of the habits and workings of the Teredo 

 Navalis, as extracts from the "Archives of Holland" or extracts 

 from the report of the Dutch Commission, on the subject under 

 your consideration. 



"Teredos penetrate wood naturally by very small openings in 



