1908. CoLGAN. — Ship-wo7'm a7id Wood-boring Crustaceans. Ii 



passing beneafh the uails, had been worked from the unpro- 

 tected to the protected parts of the pile, while the surface 

 layer of this latter part remained quite intact, thanks to its 

 coating of oxide. 



At low tide, on the 4th November last, Mr. Gray took me 

 in a boat to examine the superannuated piles still rising from 

 the w^ater beneath the Carlisle Pier, alongside of the sound 

 working piles of comparatively recent date. We procured a 

 series of specimens of the old wood, thickly populated with 

 living Chelura and Limnoria, and I was pointed out "some 

 large piles of greenheart, driven about nine years ago, which 

 had unexpectedly begun to show signs of decay, for this wood 

 was reputed immune from attack. Some shavings chipped 

 from the surface with an adze were found to swarm with 

 living Limnoria, adult and juvenile. A few Chelura were 

 also present, and the wood for full}' a quarter of an inch from 

 the surface was quite honeycombed with borings. 



Thompson^ notes the vitality of Chelura, which he found to 

 remain alive out of the water in its borings for 90 hours. 

 With me this species showed a vitality even more remarkable. 

 In sections of old piles taken from Carlisle Pier at 4 p.m. on 

 the 4th November last, and kept fully exposed to the air in a 

 dry room, individuals were found living at 5 p.m. on the 14th 

 November, so that they lived in their borings without any 

 fresh immersion in salt water for ten days, or, to be perfectly 

 accurate, for 241 hours. According to Bate and West- 

 wood,- Limnoria lives at least for a fortnight in wood taken 

 out of the water and placed in a dry room. It seems clear, in 

 fact, that both species live in their wooden cells so long as 

 these retain any moisture. 



As showing the vast numbers of these crustaceans which 

 must be simultaneously at work on a large pile, I may men- 

 tion that I extracted from a small piece of Memel fir from the 

 pier, not more than half-an-inch in cubic contents, 63 living 

 specimens of Chelura and 48 of Limnoria. Observation of 

 the living animals showed that Limnoria was markedly 

 sedentary in habit, while Chelura was most active. The 

 former rarely, if ever, issued entirely from its burrow, its 



' Ann. and Mag. Nat. Hist. 



2 " British Sessile-eyed Crustacea." 



