CHAPTER VIII: THE BASKET SHELLS. 

 DOG WHELKS 



Family Nassid^e 



Shell small, ovate; spire elongated; base of aperture a 

 notch or short recurved canal; columella callous; operculum 

 horny; nucleus apical. Body with forked tail; foot long and 

 broad; siphon long; tentacles slender, bearing eyes; radula well 

 developed; teeth arched, serrate. A world-wide marine family, 

 near shores of temperate warm seas. Habits active, predatory. 



Genus NASSA, Lam. 



Characters of the family. Over one hundred species. 



These shells have their name from their resemblance to the 

 tapering, narrow-mouthed wicker baskets used in Europe to catch 

 fish and lobsters in. The cancellated surface of the shells suggest 

 basketry. The moUusks are taken in considerable quantities 

 adhering to these baskets to which they are attracted through 

 their keen sense of smell, and their corresponding appetite for fish, 

 dead or alive. The peasants eat the species mutahilis in Italy. 



The scavenger work done by these dog whelks certainly puts 

 them on the white list of useful mollusks. The seashore is fresh 

 and clean because they help other scavengers to remove such 

 wrecks of fish and other creatures as the waves wash ashore. 

 These, if left, would become vilely offensive in a short time. 

 No better cleanser of a polluted aquarium is known than a 

 handful ot dog whelks. 



The broad foot with its forked tail and lobed front is interest- 

 ing to watch as it glides along leaving a trail in the mud. The 

 animal finally rests under a small pellet of mud, at the end of the 

 trail. What is intended as a mode of concealment is in reality 

 a prominent sign board: "If your looking for the maker of this 

 trail you '11 find him under a ball of mud at the end." 



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