CRUSTACEANS. 241 



§ 10. LiMNORIA TEREBRANS. — Plate LXV. figs. 7, 8, 9, 10, 11, 12, 

 13, 14, 15. 



A Chain Pier, of considerable dimensions, was erected on the 

 southern shoi'e of the estuary of the Forth, about two miles from Edin- 

 burgh, in the year 1821. This structure proved of great public utility. 

 The previous inconvenience of the regular ferries along the coast, the 

 habitual intemperance of the boatmen, and the total deficiency of autho- 

 ritative regulations, still too general from the feeble police of Scotland, 

 rendered them alike dangerous and disagreeable. Providentially few 

 serious accidents occurred amidst perpetual painful tumult, disorder, and 

 alarm. Every improvement corrective of these grave annoyances be- 

 came of the highest importance. 



Besides, an enormous expense to the nation was incurred from inju- 

 dicious and incessant repair on Lcith harbour, within a mile of this new 

 structure, the Chain Piei'. Above £240,000 of debt had been con- 

 tracted by the managers of that harbour for repairs and alterations, 

 chiefly about the years 1836 and 1840. 



No expedient could have proved more beneficial, or could have suc- 

 ceeded better at first, than the structure now specified. But, it seems 

 incident to Scotland, that almost every imjDortant plan for public or 

 private benefit, is followed by immediate failure. 



Nevertheless, without imputing blame to individuals, so little do 

 mankind knoAV or study the operations of Nature, so weak and shallow 

 their penetration of futurity, that this strong and costly structure, which 

 bids defiance to the tempest, was attacked by a diminutive insect, whose 

 ravages threatened its speedy ruin. 



Having a favourable opportunity, my attention was directed to this 

 diminutive animal, originally in the year 1826, when I was enabled to 

 prosecute some enquiries with comparative facility, from Mr Scott of 

 Trinity, the owiier of the structure ; Captain Donaldson Boswall of the 

 Royal Navy ; Mr Dall, Superintendant of Go\"emment stores, and others 

 taking an interest in the subject. 



2 H 



