AMPHIPODA. 399 



Esq. — who is officially connected with the harbour— to have all the 

 beacons or " perches " marking the channel of the river (which they do for 

 about two miles at the upper part of the estuary) examined, and if they 

 proved to be injured, to favour me with specimens of the damaged wood. 

 All this he kindly had done in the month of May, 1847, when the beacons 

 proved to have been all attacked, and those most under the influence of 

 the fresh-water to have suffered equally with those nearest to the open 

 sea. The ship-carpenter, who cut the damaged portions off that were 

 sent me, stated to my friend that some old mooring-buoys so high up as 

 the Old Long Bridge were found on removal injured in the same man- 

 ner. The Limnoria was the only borer of any kind found in the beacons 

 alluded to. 



It must be mentioned, that, judging from the superior size of the Che- 

 lura borings to those of the Limitoria in Dublin Bay, I had from that 

 circumstance noted down the perforations in pieces of oak and black birch 

 washed ashore at Belfast as the work of the Limnoria ; but perceiving, 

 on examination of the wood from Ardrossan, that the borings of the two 

 species may not only be of equal size, but that those of the latter species 

 may be the larger, I was taught that the presence of the excavator himself 

 must be essential to settle the point, and that circumstantial evidence is 

 insufficient. The wood in question had been so long tossed about in the 

 sea that the animals were all washed out : — both pieces had also been 

 bored by the Teredo norrer/iea (T. naralis, Turt.). 



In reference to the length of time that the CJielura will live after being 

 removed from its native element, the following note was made. A few 

 specimens taken from the sea on Monday morning and received by me in 

 the afternoon of that day were alive on Thursday morning, or seventy- 

 two hours afterwards, when, leaving home for England, I took the piece 

 of wood containing them with me, and on examining it next day found 

 them dead ; they had probably lived out of their native element about 

 ninety hours. A number had lived in the same wood for about sixty-five 

 hours; they were alive on Wednesday night at 12 o'clock, and dead on 

 the next morning at 7 o'clock. The wood in which they were, was a 

 small piece about six inches in length and an inch in thickness ; it was 

 not wetted since being received on Monday, and was kept in a warm 

 room (about 65° Fahrenheit) all the time. The apparently simple fact of 

 the species thus living so long out of water has a very important bearing, 

 for it suggests to us that this species could, like the Limnoria, commit its 

 devastations in wood left dry by the ebbing of every tide. Dr. Cold- 

 stream informs us that the latter species " often effects a lodgment in 

 piles very near high watei'-mark, where it is left dry by the receding 

 tide during the greater part of every twenty-four hours," and I have very 

 little doubt that the Chelnra could play a similar part. I have not heard 

 that the extent of the damage done at Ardrossan by the destructive ani- 

 mals noticed in this communication has yet been estimated, but on lately 

 writing to my obliging friend and correspondent there, requesting him to 

 procure if possible perfect specimens of the Xi//opJuu/a for dissection — the 

 testaceous portions only had before been sent — he replied that the ojipor- 

 tunity for so doing was now past, " as the damaged jiortions of the dock- 

 gates had been replaced by sound timber." 



