at one end of an aquarium containing aerated sea water , At varying distances 

 from these meats he positioned drills and watched their movements, The 

 results indicate that under the conditions of the experiment oyster meat was pre- 

 ferred to any other and mollusks were preferred to fin fishes By introducing 

 living oyster spat he determined that a large proportion of the drills were 

 attracted to the spat m spite of the fact that they had to circumvent freshly killed 

 oyster meatto reach them 



No information is available on the role of firm surface encrustations 

 (sessile protozoans, coelenterates, bryozcans minute algae ; and similar organ- 

 isms) in the diet of the oyster drill . The writer has observed drills rasping 

 the surface of encrusted shells in the laboratory a number ol times It is possible 

 that this source of food, particularly in the absence of other kmds, may be 

 utilized more than has been appreciated, and may tide them over long periods of 

 time Since so far as is known drills remaining on grounds from which oysters 

 have been harvested are not eliminated by the removal of the bivalve s ; it would 

 seem that another source of, food is utilized. Stauber (.1943) suggests that even a 

 small quantity of food (kind pot specified) remaining on the bottom will maintain 

 them . A study of this aspect of the nutrition of Urosalpinx would undoubtedly 

 provide u seful information 



T. C. Nelson (1923) in Little Egg Harbor. New Jersey, made the significant 

 observation , that where Bracfiidontes recurvus were attached to young oysters. Uro 

 salpinx continued to feed on the oysters until the oysters developed shells thicker 

 than those of the mussels, then moved to the mussels The writer (1951) in a series 

 of field cage experiments in .this same bay likewise noticed that the presence of 

 such buffer species as thinner valved mollusks affords some temporary protection 

 to the thicker shelled bivalves , In a mixture of 200 Volsella ( =Modiolus) dermssa 

 2-8 cm, long- larger sizes predominating; 74 oysters, 2.5-15 cm, long; 50 

 Mercenana mercenana, 1 .5-3 cm long; and .100 Uro sal pinx, 20-30 mm, m height, 

 confined for 47 days during the summer, Urosalpinx drilled all of the ribbed 

 mussels, half of the large and all of the spat oysters, and none of the hard clams 

 Jn view of the fact that during the summer the siphena! tip of the valves of Mercenan a 

 frequently projects a short distance above the bottom, it is surprising that no 

 Mercenana were drilled. It is possible that Merceraria dislodges such predators 

 by diggirg deeper into the sediment 



It is a provocative tact, and one worthy of further research leading to 

 possible control of the drill; that Urosalpinx only infrequently attack the jingle 

 shell Anomia, even though in many areas within its range this bivalve is one of 

 the most conspicuous and abundant animals on the bottom In aquaria GaJ.tsoff et 

 al (1937) observed that of all the foods offered to drills the jingle shell remained 



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