ORDER BIMUSCULOSA. 87 



as bait for fishes : the method of taking them is very 

 singular. Having discovered the place of retreat of the 

 creature, by observing the hole in the sand which leads 

 to its chamber, the fisherman throws into its entrance a 

 small quantity of salt. Although an inhabitant of salt 

 Avater, the pure salt produces so irritating an effect on 

 the extremity of its body, that it quickly mounts to the 

 surface ; the fisherman, waiting for its appearance, 

 snatches hastily at it, and if he succeeds in seizing it 

 firmly, makes good his capture; but if not sufficiently 

 active, and the animal escapes, the application of fresh 

 salt produces no further effect; either it is not sensible 

 to the additional infusion of salt, or, which is most likely, 

 the instinct of self-preservation causes it to put up with 

 the inconvenience rather than be taken. In this case, no 

 other means are left of securing it, than using an iron 

 instrument to dig it out with. The number of species is 

 upwards of twenty. 



Thi;: Date-Shaped Pholas, {Pholas dactyloides.) 



These creatures have much more powerful means of 

 boring than the solens, for not only do they imbed them- 

 selves in hard clay, but even in stone and lava. In what 

 manner this is effected has been the subject of much 

 dispute ; it is almost certain that the process is not me- 

 chanical, for their soft body, and the fragile nature of 

 their shells, seem an insuperable bar to such a proceed- 

 ing. Some authors have asserted that the hole is formed 

 by means of an acid secreted by the animal, which acts 

 chemically on the stone ; but there are two reasons 

 against this solution of the difficulty ; first, no acid liquid 

 has been discovered in the living animal, and, secondly, 



