160 
EDIBLE BRITISH MOLLUSKS. 
far for the operation of boring ; but how to account for 
the holes fitting the shape of the animal inhabiting 
them ? To this I fearlessly answer, that this is only 
the case when the Pholas is found in the rock which 
it entered when small. This mollusk evidently bores 
merely to protect its fragile shell, and not from any love 
of boring ; and in this opinion I am borne out by my 
own specimens. The young Pholas, having found a 
substance suitable for a habitation, ceases to bore imme- 
diately that it has buried its shell below the surface of the 
rock, etc. It remains quiescent until its increased 
growth requires a renewal of its labours. It thus con- 
tinues working deeper and deeper, and, should the sub- 
stance fail or decay, it has no alternative but to bore 
through, and seek some fresh spot where it may find a 
more secure retreat.^’ 
At Amroth, near Tenby, is a submerged forest, the 
trees of which are completely perforated by the Pholas ; 
and at spring-tides fine specimens may be collected. 
Montagu remarks that, whilst it is the general habit of 
shipworms [Teredo navalis, or Teredo norvegica) to bore 
parallel with the grain, the Pholas perforates the wood 
across the grain.* 
Mr. J. G. Jeffreys mentions that Redi, in a letter to 
his friend Megalotti, describes the Teredo as being not 
only eatable, but excelling all shellfish, the oyster not 
excepted, in its exquisite flavour. Nardo also praises it, 
and wonders why the Venetians, who call it bisse del 
legno, do not eat it.f 
The German name for the Pholas is very appropriate, 
viz., die bohrmuschel, steinbohrer, or pierce-stone ; in 
* Forbes and Hanley, Brit. Mollusca. 
t Brit, Conch, vol. hi. p. 159. 
