and Limnoria terebrans. 127 



• The Teredo holds not undisputed sway over the piles at Port- 

 patrick, as the disastrous effects of another species are but too 

 apparent. This is a very minute crustaceous animal, first de- 

 scribed about twenty years ago by Dr Leach (Edin. Encyc. 

 vol. vii. p. 433, and Linn. Trans, vol. xi. p. 370), who made of 

 it a new genus, and announced it under the appropriate title of 

 Limnoria terebrans. Kirby and Spence, in their " Introduction 

 to Entomology" (vol. i. p. 236, 4th edition), observe concern- 

 ing it : — " If this insect were easily introduced to new stations, 

 it might soon prove as destructive to our jetties as the Teredo 

 navalis to those of Holland, and induce the necessity of substi- 

 tutino- stone for wood universally, whatever the expense ; but 

 happily it seems endowed with very limited powers of migration, 

 for though it has spread along both the south and east piers of 

 Bridlington Harbour, it has not yet, as Mr Lutwidge informs 

 me, reached the Dolphin, nor an insulated jeity within the har- 

 bour." 



At Portpatrick the real is doubly worse than the imaginary 

 danger contemplated by these benevolent authors, for the dread- 

 ed Teredo navalis and the Limnoria terebrans have here com- 

 bined their forces ; the former consuming the interior of the pile, 

 whilst to the latter the exterior falls a prey. The result of these 

 united efforts can hardly fail to be the utter and speedy destruc- 

 tion of all the timber in the pier. 



A piece of sound pine timber which I examined, and which 

 had been originally nine inches in diameter, when taken up af- 

 ter being five years and a half used as a pile, was so reduced by 

 the continued operations of these animals, as to contain not more 

 than about an inch in breadth of sound timber in any part, and 

 in several places was pierced entirely through. This pile was 

 placed fifteen feet below high-water mark, and only left dry du- 

 i-ing the low water of spring-tides. 



In the " Introduction to Entomology," it is stated that " no 

 other remedy against the attack of the Limnoria is known, than 

 that of keeping the wood free from salt water for three or four 

 days, in which case it dies." I remarked this animal to be much 



was more especially the case in the island of Achil, where we in vain sought 

 for a piece of even trivial dimensions, that had not formed an habitation for 

 the Teredo, previous to being subjected to the use of man. 



