Tank No. 22. 
61 
formed by these shells. It is hence concluded that the temple must 
have sunk under the level of the sea for a time and then have been 
raised again. 
Fig. 102. Two specimens of Litho- Fig. 103. Pholas dactylus in a 
domus dactylus within a piece of stone, 1/2 nat. size, 
tufa, Y 2 nat. size. 
Deeply buried in the sand may be found the liazor-shells, Solen 
Fig. 104) and Solecurtus (Fig. 105), which are sought after as delicacies. 
They are sold on the market with other edible shells as "Fruits of the 
Sea” (Frutti di mare], and are eaten raw. 
While all the above named bivalves afford examples of the still-life 
of the ocean, the Cockle and Scallop are by no means slow of movement. 
The Cockle, Cardium (Fig. 106), is a genus comprising many species; it 
derives the Latin name from the form of its shell. The animal has a 
Fig. 104. Solen vagina, ^2 nat. size, on the left the foot, on 
the right the respiratory tubes. 
„ Fig. 105. Solecurtus strigilatus , ^2 nat. size, on the left the foot, on the 
right the respiratory tubes. 
long, bent foot of a brilliant red colour, and knows how to make good 
use of it. It presses it on the ground, stiffens it out by forcing blood 
into it, and in this way clears a distance of several feet; this jump¬ 
ing seems a most surprising movement for a shell to make, but it is 
not solely restricted to the Cockles. It can also burrow very rapidly in 
the sand, using the bent foot as a hook. It is a very toothsome shell-fish 
and is collected in enormous quantities on the British coasts. 
