192 



THE NATURE BOOK 



anything else will induce it to cdnie 

 out again. 



If we are lucky, and capture the Solen. 

 we may witness the remarkable and rapid 

 manner in which the creature burrows. 

 On being placed on the sand, the Solen at 

 once protiiides a flat-shaped foot which 

 ends in a }wint. It then with ease proceeds 

 to drive this singular organ into the sand, 

 and bending the 

 pointed end into 

 the shape of a 

 hook, acquires a 

 sufficient hold to 

 drag the cylin- 

 drical shell into 

 an upright ]:>osi- 

 tion. The foot is 

 then unbent, elon- 

 gated, and again 

 forced downwards 

 to a depth of one- 

 half to two-thirds 

 of the length of 

 the shell, and then 

 the foot com- 

 pletely changes its 

 shape. Without 

 diminish ing in 

 length, it becomes 

 cylindrical, swell- 

 ing out near its 

 extremit\' into a 

 fleshy globe, which 

 becomes securely 

 embedded in the 

 sand. Then by 

 shortening that 

 portion of the foot 

 which is situated 

 between the glo- 

 bular swelling and the shell, the latter 

 is drawn downwards, and this process. 

 being rapidly repeated, the creature buries 

 itself with astonishing velocity. 



On all rocky shores the Limpets abound, 

 and this in spite of many foes. On a lonely 

 stretch of rock-strewn shore one may 

 watch one of the sea birds, called the 

 Oyster Catcher, at work, knocking the 

 Limpets off the rocks by sudden, well- 

 directed blows of its punch-shaped bill, 

 and then scooping out and devouring with 

 evident relish the fleshy ])arts of the un- 

 fortunate shell-dwellers. Another foe of 

 the Limpet is the Dog-whelk, which lives 



NATICA, OK SEA 

 THE CHITON, OR 



on the shore from close to high-water 

 mark down to and beyond low-water mark. 

 If we look about carefully amongst the 

 rocks we are pretty sure to find a Dog-whelk 

 perched u})on a Limpet, engaged in the 

 process of drilling a neat hole through the 

 shell of its tmfortunate and helpless victim. 

 When the Dog-whelk wants a meal, it 

 climbs up on to the crown of the Limpet 

 shell, and with the 

 aid of its file-like 

 tongue proceeds to 

 rasj)a hole through 

 the shell, and then 

 inserting its pro- 

 t r u s i 1 e mouth, 

 literally eats the 

 Limj)et out of 

 house and home. 



Though of hum- 

 ble exterior, the 

 Limpet is in its 

 wa}^ a really re- 

 markable creature. 

 The tenacity with 

 which it clings to 

 the rock upon 

 which it is resting 

 is proverbial, and 

 e.xperiments have 

 proved that it 

 takes about a 

 seventy- pound 

 pull to dislodge 

 a fair-sized Limpet 

 when once the 

 creature has got a 

 firm hold. Inside 

 its mouth it has 

 a long, ribbon- 

 shaped organ, 

 called the radula. or tongue, which has 

 many teeth upon its surface, and is used 

 by the Limjiet with a rasping movement 

 when feeding. There are about i6o rows 

 of teeth on this curious tongue, and as 

 each row has twelve teeth, the Limpet 

 has about 1,920 teeth in all. 



The familiar Periwinkle is also the pos- 

 sessor of a remarkably long tongue, fur- 

 nished with some 500 to 600 rows of 

 teeth, and it is with this wonderful organ ' 

 that the Periwinkle rasps away at the 

 seaweeds w'hich form its staple diet. 



r""re(iuently to be met with on the rocks 

 at low water is a curious shell-dwellci% 



SNAIL. 

 ARMADU.LO-SHELL, 



