158 Mr. W. Thompson on Teredo norvegica, fyc. 



noria terebrans as at present existing on certain parts of the coasts 

 of the British Islands." The chief localities commented on, were 

 Portpatrick, on the coast of Scotland, and Donaghadee on that 

 of Ireland, in both of which places, floating timber as well as 

 the wood-work of the piers was destroyed to a most serious extent, 

 the Limnoria being by far the more destructive of the two spe- 

 cies. The Teredo was in that communication further mentioned 

 as having attacked the wood- work of a sluice at Youghal, on the 

 coast of Cork, and as having committed great havoc at the har- 

 bour of Dunmore, on the coast of Waterford — at the former 

 locality the Limnoria was also met with. This species alone — 

 without the addition of the Teredo — was noticed as destroying in 

 1834 the jetty at Kingstown harbour, in Dublin bay. 



I am not aware of the two destructive agents — Molluscan and 

 Crustacean — being commented on as conjoined in their evil 

 labours, previous to the publication of that paper ; nor do I 

 remember having seen any notice of three species of these borers 

 — and certainly not of four — having been at work in any one 

 locality *. 



Early in the month of May last, Major Martin of Ardrossan, 

 in Ayrshire— a gentleman well-known as a lover of natural 

 history, and as a successful collector of objects of zoological and 

 botanical interest— sent me a piece of wood bored by the Xylo- 

 phaga dorsalis, and labelled as from the dock-gates, Ardrossan. 

 Not having before heard of this animal attacking the fixed timber 

 of our harbours — it has been found in drift wood or portions of 

 vessels cast ashore — I made immediate inquiry respecting it, 

 suggesting at the same time that the Teredo should be looked 

 for, and also, that the outside of the timber should be examined 

 for very minute borings : — if such were observed, I requested to 

 be informed whether they were of more than one size. Speci- 

 mens of wood excavated by the Limnoria and Chelura were for- 

 warded by post for my friend's guidance. 



I shall here give his replies to queries on the subject gene- 

 rally. 



The piece of wood sent was a portion of the dock-gates. The 

 Xylophaga has been known to be consuming them since the 

 docks were opened in March 1844. It has been known for a 

 very considerable time along this coast, where there is no fresh 

 waterf. It attacks timber of all kinds: for instance, the wooden 

 pier (the supporters of which are nearly destroyed) and other 

 timbers that are under water about the quays, and have been 



* Philippi, writing in 1839, mentions the Teredo navalis, Linn., being in 

 the same timber with the Chelura at Trieste. 



f It is perhaps twelve years since specimens from that locality were sent 

 to me, but I imagined that they had been found in drift timber. 



