490 MOLLUSC A. 



ami the opi'n-iilatt'd norite retire into his home, but the enemy, with rasp-like tongue, armed 

 with silieioiis teeth, tiles a hole throutrh the shell — vain shield where instinct guides the attack! 

 Of the myriads of small shells which the sea heaps up in every sheltered nook, a large proportion 

 will I.e foun«l thus hored by the whelks and purples; in many fossil-shell beds, nearly half the 

 bivalves and sea-snails are perforated — the relics of antediluvian banquets. 



Tliis is on the sliore, or on the bed of the sea; far away from land the carinaria and firola 

 pursue the floating acalephe ; and the argonaut, with his relative the spirula, both carnivorous, 

 are fonml in the high seas in almost every quarter of the globe. The most active and rapacious 

 of all are the ealamaries and cuttles, who vindicate their high position in the naturalist's system 

 b\ preying even on fishes. 



As the shell-fish are great eaters, so in their turn they afford food to many other creatures — 

 fullilling the universal law of eating and being eaten. Civihzed man still swallows the oyster, 

 and with .some the snails are still reckoned a dainty dish; mussels, cockles, and periwinkles are 

 in <:reat esteem with children and the other unsophisticated classes of society; and so are scallops 

 and the lialiotis, where they can be obtained. Two kinds of whelk are brought to the liritish 

 markets in great quantities; the arms of the cuttle-fish are eaten by the Neapolitans, and also 

 by the East Indians and Malays. In seasons of scarcity, vast quantities of shell-fish are con- 

 sumed by the poor inhabitants of the European coasts. Still more are regularly collected for 

 bait ; the calamary is much used in the cod-fishery off Newfoundland, and the limpet, whelk, 

 and clam on various coasts. 



Many wild animals feed on shell-fish; the rat and the raccoon seek for them on the sea-shore 

 when pressed by hunger; the South American otter and the crab-eating opossum constantly 

 resort to salt marshes and the sea, and prey on the moliusca; the great whale lives habitually on 

 the snndl floating pteropods ; sea-fowl search for the littoral species at every ebbing tide ; while, 

 in their own element, the marine kinds are perpetually devoured by fishes. The haddock is a 

 great conchologist, and some good northern sea-shells have been rescued, unbroken, from the ^ 

 stomach of the cod; while even the strong valves of the cyprina are not proof against the teeth 

 of the cat-fish. Many species fall a prey even to animals much their inferiors in sagacity : the 

 star-fish swallows the small bivalve entire, and dissolves the animal out of its shell ; and the 

 bubble-shell, itself predacious, is eaten both by star-fish and sea-anemone. The land-snails aflford 

 food to many birds, especially to the thrush tribe; and to some insects, for the luminous larva 

 of the glow-worm lives on them, and some of the large predacious beetles occasionally kill slugs. 



The greatest enemies of the Moliusca, however, are those of their own nation ; scarcely one- 

 half the shelly tribes graze peacefully on sea-weed, or subsist on the nutrient particles which the 

 sea itself brings to their mouths ; the rest browse on living zoophytes, or prey upon the vege- 

 table feeders. 



Yet in no class is the instinct of self-preservation stronger, nor the means of defense more ade- 

 quate ; their shells seem expressly given to compensate for the slowness of their movement and 

 the dimness of their senses. The cuttle-fish escapes from attack by swimming backward and j 

 beclouding the Avater with an inky discharge ; and the sea-hare pours out, when irritated, a ' 

 copious purple fluid, formerly held to be poisonous. Others rely on passive resistance, or in 

 concealment for their safety. It has been frequently remarked that molluscs resemble the hue 

 and appearance of the situation they frequent ; thus, the limpet is commonly overgrown with 

 balaiii and sea-weed, and the ascidian with zoophytes, which form an effectual disguise ; the lima 

 and modiola spin together a screen of grotto-work. One ascidian, .1. cnchlir/cra, coats itself with 

 shell-sand, and the carrier-trochus cements shehs and corals to the margin of its habitation, or 

 so loads it with pebbles, that it looks like a little heap of stones. 



It must be confessed that the instincts of the shell-fish are of a low order, being almost limited 

 to self-preservation, the escape from danger, and the choice of food. Their history offers few i 

 of those marvels which the entomologist loves to relate. An instance of something like social ' 

 feeling has been observed in a Roman snail, who, after escaping from a garden, returned to it in . 

 quest of his fellow-prisoner ; but the accomplished naturalist who witnessed the circumstance, 

 hesitated to record a thing so unexampled. The limpet, too, if we may trust the observations ' 





