506 CHELURIDJE. 



illustrations of this genus leaves little doubt but that 

 such is the case, although it might be thought that the 

 large plumose antennas would considerably interfere with 

 the action of the mouth in working the progressive course 

 of the tube. On the other hand the great and powerful 

 antennas cannot be used for the purpose of rubbing 

 down the wood, or we should find evidence in the worn 

 hairs at the extremity of the organ.* 



We believe that the posterior pair of caudal ap- 

 pendages are important organs in assisting the animal 

 to effect a retrograde movement when within its chamber. 

 When free in the water its movements are very active, 

 swimming chiefly on the back ; and Professor Allman says 

 that when out of the water it is capable of taking a 

 considerable spring, the immensely-developed branch of 

 the last pair of caudal appendages doubtless acting in 

 the same manner as the fork of the Poduridce. 



It appears to us singular, that as the subject of the 

 destruction of submarine architectural timber has been 

 so much studied and examined for so many years, in an 

 economical point of view, this animal, although so much 

 larger than the well-known Limnoria, should not have 

 been described until 1839, when it was found by Pro- 

 fessor Philippi at Trieste. Some specimens, labelled 

 Britain, in the collection of the British Museum, were 

 obtained by Dr. Leach, but their locality has not been 

 preserved, although supposed to have been taken by 

 himself or Col. Montagu in Devonshire or Cornwall. 

 Early in 1847 it was procured at Dublin in the piles of 



* Being desirous of studying this subject, upon being placed upon the 

 Committee " For Enquiring into the best Mode of Preserving Submarine 

 Timber from the Ravages of the Teredo and other Animals," Mr. Spence 

 Bate applied, through the Admiral Superintendent of the Dockyard at 

 Plymouth, for permission to make some investigations in that naval arsenal, 

 a favour which the Admiralty refused. 



