CHAPTER III: THE OYSTER DRILL 



Family MuRiciD/t 



Genus UROSALPINX, Stimps. 



Shell elongated, oval, longitudinally ribbed or undulated, 

 spirally striated; varices none; aperture ending in short canal; 

 outer lip toothed, operculum semi-cordate, nucleus lateral and a 

 little below middle; lingual ribbon well developed; ova capsules 

 oblong, shouldered, widest near top. 



A small genus of twenty recent species differing from Ocinebra 

 in its lack of varices, open canal and smoother shell; resembling 

 Trophon in its dentition and Purpura in its operculum. It seems 

 to Tryon a connecting link between Murex and Fusus. Distri- 

 bution, Atlantic coast of America, Cape Horn, Cape of Good 

 Hope, New Zealand, California. 



The Oyster Drill (U. cinerea, Say) is a small unobtrusive 

 looking citizen of rocky shores; his modest yellowish gray shell 

 attracts little attention. The solid spire bears strong varicose 

 folds across the whorls; the largest specimen is scarcely an inch 

 long; the stronghold is closed by a horny door. You may find 

 the rocks and drift-wood fragments alive with these mollusks at 

 low tide almost anywhere from Maine to Florida. 



This is the "oyster drill," the despair of oystermen, who 

 place it first among the destructive agencies against which the 

 oyster industry has to fight constantly for its life. 



The animal has an extremely small foot, with a yellowish 

 border and dotted with gray above. The small head protrudes 

 just far enough to show its black eyes. The siphon reaches scarcely 

 beyond the tip of the canal. 



The drill has an insatiable hunger and thirst for oyster pulp, 

 and untiring industry in appeasing its appetite. It moves slug- 

 gishly among the helpless bivalves, chooses a victim, and with 

 its strong toothed radula soon bores a neat round hole through 

 one valve near the hinge. It is the method used by all carniv- 



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