EXCAVATORS. 349 



seen occasionally collected in small earthy pellets 

 about the margin." l 



Singularly enough, there are at least two kinds of 

 excavating crustaceans (allied to the shrimps) which 

 are found around our shores, excavating timber in 

 the sea, destroying the woodwork of piers to a most 

 serious extent. At first called the Limnoria and the 

 Chelura, names since amended and altered, we shall 

 continue to designate them as such. Both the crusta- 

 ceans labour harmoniously together in the work of 

 destruction, and are mingled in the wood as if they 

 were all of one species. " They can be readily dis- 

 tinguished from each other, either when alive or 

 dead, the Chelura being of a reddish, the Limnoria 

 of a pale greyish-yellow hue, resembling that of 

 light-coloured pine or fir. As they retain their 

 colours after death, we may even years afterwards 

 distinguish the tv/o species in the excavations which 

 they had formed, in timber subjected to their ravages. 

 From this circumstance, added to that of their 

 burrows being formed in the closest contiguity, and 

 many of the creatures dying in them, after the 

 timber has been removed from the sea, we may in 

 our museums display whole catacombs of them, as 

 closely packed as ever were mummies in the best- 



1 " Catalogue of British Non-Parasitical Worms," by George 

 Johnston, M.D. (London, 1865), p. 214. 



