Another common name, proboscis worm, less widely used, calls attention to the most distinctive feature of nemerteans. This is a long, extensible, tubular proboscis that can be shot out the front end with explosive force to grasp prey or discourage enemies. The proboscis coils about the prey, holding it firmly and entangling it in sticky mucus which may be irritating or even poisonous. The proboscis is also everted as a device for burrowing in sand or mud or for attaching to objects as an aid in creeping about. It can be made to evert by irritating the animal, by plunging it into fresh water, or by placing it in a small dish of sea water and cautiously adding alcohol, drop by drop. The accurate aim of the proboscis receives recognition in the technical name of the phylum, Nemertea, from a Greek word that means "unerring." In some of the commonest worms the tip of the proboscis is armed with a sharp spike or stylet, which pierces the prey, sometimes several times, before a toxic secretion is poured on. Worms may have two or more pouches with a reserve supply of stylets, so that replacement can be made quickly if the main one is damaged. When not in use the proboscis is sheathed in a muscular tube that lies above the digestive tract.
Another common name, proboscis worm, less widely used, calls attention to the most distinctive feature of nemerteans. This is a long, extensible, tubular proboscis that can be shot out the front end with explosive force to grasp prey or discourage enemies. The proboscis coils about the prey, holding it firmly and entangling it in sticky mucus which may be irritating or even poisonous. The proboscis is also everted as a device for burrowing in sand or mud or for attaching to objects as an aid in creeping about. It can be made to evert by irritating the animal, by plunging it into fresh water, or by placing it in a small dish of sea water and cautiously adding alcohol, drop by drop. The accurate aim of the proboscis receives recognition in the technical name of the phylum, Nemertea, from a Greek word that means "unerring." In some of the commonest worms the tip of the proboscis is armed with a sharp spike or stylet, which pierces the prey, sometimes several times, before a toxic secretion is poured on. Worms may have two or more pouches with a reserve supply of stylets, so that replacement can be made quickly if the main one is damaged. When not in use the proboscis is sheathed in a muscular tube that lies above the digestive tract.
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