104 



The fishermen at the Isle of Man have found that 

 the best bait for their whelk-pots is Cancer pa-gurus, the 

 edible crab, used fresh. The whelk inserts the proboscis 

 through the holes broken into the carapace of the crab. 

 Whelks have been observed to attack living lamelli- 

 branchs, and on one occasion at Port Erin a large 

 specimen of Bucciiium was observed to prevent a Pecten 

 maximus from closing its valves by inserting the anterior 

 end of the shell between them. It then attacked the 

 adductor muscle with its long proboscis, and so at the 

 same time obtained food and disabled the closing 

 mechanism of the scallop. The same process of disabling 

 the prey has been observed by Colton in the American 

 genera Fulgur and Sycotypus. Colton experimented with 

 these animals, and found that when an oyster was given 

 to a hungry Sycotypus , the latter crawled on the top of 

 the oyster and waited until the valves were opened. It 

 then rotated on the columella and inserted the end of 

 its own shell between the valves. Forty minutes later it 

 left an empty shell. Fulgur actually hammers the 

 margin of lamellibranch shells by grasping with its foot 

 and contracting the columellar muscle sharply. The 

 proboscis is then inserted into the orifice so made. The 

 impression one usually derives from the literature of the 

 subject is that the whelk actively bores through 

 lamellibranch shells by means of its odontophore. 

 Colton states, however, that the radular teeth of Fulgur, 

 Nassa, Lunatia and Purpura do not appear as if worn 

 down against a hard substance, but broken off irregularly. 

 To this list the whelk can be added, for the old teeth 

 present a most ragged appearance (fig. 15). 



On one occasion a whelk was observed attacking a 

 dead Nephrops (the Norway lobster). It held the 

 crustacean by means of the anterior part of the foot, 



