L I M U L U S. 



4!) 



ticable remedies against the attacks of this pest, \ve 

 will notice more precisely the extent to which the 

 damage caused by it has extended in some of our 

 public works, our information being condensed from 

 Mr. Coldstream's paper. During the building of the 

 Bell Rock Light-house, it was necessary to erect a 

 temporary wooden building, in which the engineer 

 and his assistants resided, and which was supported 

 by twelve large beams of Memel fir fixed in bolt 

 holes cut in the rock ; the sides of these beams were 

 charred and pitched, but the bottoms, which closely 

 fitted to the holes, were left naked. In the second 

 year the edges of these timbers were in a state of 

 decay, owing to the borings of the Limnoria. The 

 logs of Norwegian pine laid down to support the 

 temporary railways were also very much destroyed : 

 the timbers, which were at first ten inches square, 

 being reduced in four years to seven inches ; that is, 

 losing at the rate of one inch per annum. In several 

 instances, also, the house timbers were so completely 

 eaten away at the bottom, that they stood clear of the 

 rock, supported only by the bolts and stancheons. The 

 piles,supporting the timber bridge at Montrose "were 

 Very much destroyed by the borings of the same ani- 

 mal, so that the stability of the whole structure was 

 seriously endangered ;" and in like manner the piles 

 supporting the Trinity Chain Pier at Leith were in 

 182.5, four years only after their first fixture, found 

 to have been so very much destroyed by the Lim- 

 noria as to be useless, and they were at a great ex- 

 pense removed and replaced by new ones ; the girth 

 of some of them which were originally forty-eight 

 inches in circumference, having been reduced to six- 

 inches, so that the least force was sufficient to break 

 them through. The attention of scientific men be- 

 came at length seriously aroused ; various plans for 

 remedying the mischief were proposed and tried ; but 

 none succeeded so well as covering the whole sur- 

 face of the pile, from the place where it met the 

 bottom of the sea to within a foot or two of mrau 

 high-water mark, with broad-headed iron nails, 

 technically called scupper nails, set close together; 

 the taste of wood, now encrusted with a thick coat, 

 as well as impregnated with oxide of iron caused by 

 the presence of the nails, probably otl'ending the 

 taste of the Limnoria. Thus a piece of wood covered 

 on three of its sides with the scupper nails was found 

 to have the whole interior eaten away, so much of 

 the exterior only being left as had been penetrated 

 by the nails on the side?. This plan was adopted at 

 an expense of about 1000/. in the Leith pier, which 

 cost 30.000/., and after four years, it was discovered 

 that none of the piles thus protected had been pene- 

 trated by the Limnoria; whilst some wood work 

 attached to the pier, but not so defended, is now 

 much destroyed. It is essential, however, to watch 

 the condition of the piles from time to time, even 

 though covered with the iron nails, because the heads 

 of the nails frequently fall off after being much oxi- 

 dated ; and it is very possible that the coat of oxide 

 which they have previously communicated to the pile 

 may also be abraded so as to leave the wood entirely 

 exposed to the enemy, and the nails which fall away 

 ought to be replaced by new ones as fast as possible. 

 We cannot take our leave of Mr. Coldstream's paper 

 without quoting at length his admirable and truly 

 philosophical observations upon the purposes which 

 the Livtnoria is fitted to serve in the economy of 

 nature, and which it will bo seen correspond in some 

 NAT. HIST. VOL. III. 



respects with the remarks which we made upon 

 the injuries arising from the attacks of insects in 

 our general article INSECT. " Although the de- 

 structive agency exerted by this minute animal be 

 forced upon our attention, chiefly by its ravages in 

 works of great practical utility, and therefore cannot 

 at first view be regarded by us with complacency or 

 admiration ; yet, upon further reflection, we must be 

 convinced that the purposes which the Limnoria is 

 fitted to serve in the great plan of the creation, nrc 

 such as could be accomplished by no other living- 

 creature with which we are acquainted, and that they 

 are calculated to contribute in no small degree to the 

 comfort and well being of man. Let us consider, for 

 instance, how possible it is that large trees or masses 

 of wood floated down by rivers might accumulate on 

 shoals at their mouths to such an extent as materially 

 to diminish the outlet for the waters, which then 

 would rise and overflow their banks, were it not for 

 the destructive boring of the Limnoria : what could 

 not be accomplished by the brute force of any marine 

 animal, and might baffle even the ingenuity and power 

 of man himself, is yet quietly accomplished by the 

 gradual but steady operations of a tiny crab." 

 " Nor must we omit to notice the possibility of its 

 being the means occasionally of causing the removal 

 of those serious obstacles to the safe navigation of 

 shallow seas, which are caused by the masts of sunken 

 vessels. But whether we be right or wrong in our 

 suppositions as to the use it may be of in the economy 

 of nature, we cannot be mistaken in regarding the 

 ravages of the Limnoria as showing what formidable 

 enemies to man the Creator can prepare, even amongst 

 what appear to us the most insignificant of His works, 

 and how He, who ruleth over all, effects important 

 purposes, by means of the smallest and apparent!}' 

 most incompetent agents." 



We must also refer to a paper by the Rev. F. W. 

 Hope, contained in the second number of the Trans- 

 actions of the Entomological Society, in which several 

 useful remedies are suggested ; and we would also 

 notice the probability, that the immersion of wood to 

 be employed in submarine works in Ryan's patent 

 solution, would al*o be very serviceable. 



LIMULUS (Fabricius). A curious exotic genus 

 of Crustacea, constituting the sub-order Xi/phnsura 

 (see article CRUSTACEA), and known by the common 

 name of king crabs, having the body covered by a 

 large and nearly rounded shell, divided into two parts, 

 the anterior being large and semilunar, and the pos- 

 terior toothed at the sides, and deeply notched be- 

 hind, and terminated by a very long and acute spine ; 

 the mouth is not provided with any sucker, the coxa 1 

 of the six anterior pairs of legs being dilated and 

 spined, and performing the office of jaws ; the anterior 

 pair of legs is very short, and seem to serve as a pair 

 of claws assisting in carrying materials to the mouth ; 

 the five following pairs are larger, and terminated bv 

 small bifid claws, but do not extend beyond the mar- 

 gins of the shell ; the terminal legs, which are ten in 

 number, are transformed into thin lamellatcd plates 

 serving for branchiae. These king crabs sometimes 

 attain the length of two feet. They inhabit the tro- 

 pical seas, frequenting the coast?, and appearing: to be 

 found only in the East Indies and the shores of Ame- 

 rica. According to M. Lrconfo, they aif given to 

 pigs for food, and the long and "pointed tail is some- 

 times employed by the Indians for the points of their 

 arrows. Their e-gs are ealrn by the Chinese. Fossil 

 I) 



