SHELLS AND MOLLUSCOUS ANIMALS. 207 



sand, pierce the animal, and bring it to light. The 

 slight motion of the sand, made by the foot, 

 sufficiently alarms the fish to induce it to throw 

 out jets of water, or it would lie secure enough, 

 for the holes are not often easily discovered. In 

 some cases salt is thrown into the cavities, which 

 so irritates the fish, that it immediately comes to 

 the surface ; but the eye must be watchful, and 

 the hand must be ready, which is to secure it, as, 

 if not seized instantly, it plunges down again, and 

 no subsequent irritation from the salt will induce 

 it to come out to face farther danger. The French 

 call the Solen Manche de couteau, from the shape 

 of its shell. Several species are found on our 

 coast. Our figure represents the common Kazor- 

 shell (Solen ensis). 



Not less difficult of capture, from the depth in 

 which they bury themselves in the sands, are the 

 different species of Mya or gaping-shells ; so called 

 because at one end the shells, instead of meeting, 

 gape open. The sand mya (Mya arenaria) is a 

 common shell-fish on our sandy coasts, making- 

 holes under the sand, which it betrays by occa- 

 sionally putting out its proboscis. This genus is 

 interesting, as including the pearl mya (Mya 

 margaritifera), sometimes called Unio elongatus, 

 which, however, is not a marine animal, but a 

 native of rivers. The pearls produced by this 

 fish are very valuable ; several pearls of great size 



