106 pholadiDjE. 



gracilis was found by M. Cailliaud on tlie faluns of 

 Touraine. Its exotic range in a recent state extends 

 from Norway to Sicily and Algeria. M f Andrew describes 

 his Spanish specimens as being of small size. Cailliaud 

 has noticed it as perforating micaceous schist at Croisic 

 in Lower Brittany. 



The " Pierce- Stone " of Petiver. In Da Costa's time 

 it was reckoned "a very excellent and dainty food." 

 Philippi says that it is esteemed in Sicily by all classes ; 

 and at Rocheile it is sold in the market and served at 

 the best tables. I am not aware,, however, that it is now 

 eaten in Great Britain ; although it is often dragged out 

 of its hole by our fishermen to entice and capture their 

 finny prey. It buries itself eight, ten, or even twelve 

 inches ; and its tubes, when fully extended, are three 

 times the breadth of the shell. Like all its congeners 

 this species is very prolific. In a spot three feet 

 square at Saundersfoot near Tenby, Mr. Jordan dug up 

 100 living specimens. He calculated, that owing to the 

 removal by the waves of a foot in depth of mud during 

 the autumn equinox of 1863, no less than 15,000 in- 

 dividuals perished ; their empty shells remained below 

 the surface. Some of them might also have been choked 

 and destroyed by a silting up, as well as by the mud 

 being disturbed in the course of its removal. The 

 late Dr. Lukis took a P. dactylus out of peat, and kept 

 it alive in clear sea water for four or five days. At the 

 end of that time it died. The shell had become so thin 

 from excessive absorption of its calcareous substance, 

 that he was unable to lift it with the animal out of the 

 water in a perfect state. Another intelligent and inde- 

 fatigable naturalist, Mr. Peach, endeavoured to discover 

 the way in which this Pholas makes its cell. He 

 carefully and patiently watched 15 or 16 of them in a 



