and Limnoria terebrans. T29 



farther west than Portpatrick, as there is at present near the 

 beach at the entrance of Belfast Bay, a large birch tree {Betida 

 alba), which was thrown ashore, after being for some time sub- 

 jected to the sea, tliat, wherever decorticated, has been eaten away 

 to the depth of some inches by this animal. The presence of 

 incrustations of Serpulce, Balani, Cliiia, Flustrce, &c., all of na- 

 tive species, on such parts of the bark as remain, affords circum- 

 stantial evidence that the tree has not been washed from anv 

 foreign locality. 



Since the above was written, I have received the following 

 additional information on the Teredo and Limnoria, from my 

 friend Mr Hyndman, who, at my request, gave attention to the 

 subject during a visit to Donaghadee (in the county of Down), 

 in February 1834. Mr Stephen, the overseer of the Harbour 

 of Donaghadee, states, tliat soon after the works commenced in 

 1828, the building float was found to be perforated by the Te, 

 redo, but that the animal did not afterwards appear in any num- 

 bers. I myself examined two piles of pine timber that had been 

 used in the works. They were put down in 1828, and taken up 

 in 1832 ; one of them had a few perforations of the Teredo in 

 it ; they were both eaten away to a considerable extent by the 

 Limnoria, which attacks all wood here exposed to the sea. Elm 

 particularly suffers from it. Memel timber, as may be supposed, 

 withstands it longer than the American pine. Mr Stephen in- 

 formed me, tliat upon one occasion on examining the bottom of 

 the steam dredge, the wooding sheeting was found to be almost 

 totally destroyed by the Limnoriae ; indeed, to such a degree, 

 tliat the men could almost thrust their hands through it. Buoys 

 used about the harbour had occasionally to be renewed, in con* 

 sequence of the destruction caused by the Limnoriae alone, as 

 they have not been yet attacked by the Teredo, nor has the lat;- 

 tcr so much injured any piles as to render them unfit for use. 

 Its effects have not been thought of, compared with those of the 

 Limnoria; and it has been against this species that any precau- 

 tions have been taken. As an experiment, Mr Stephen once 

 coated two sides of a piece of timber with the common mixture 

 of tar and sulphur, and the other two with white paint ; and ha- 

 ving done so, placed them under Avater. The sides coated with 

 the former were soon attacked by the Linuioria^, but those which 



VOL. XVIII. NO. XXXV. — JANUAllY 1835. L 



