crabs are present in Plum lalmd Sound cftiring 

 the months of June, July, and August. 



3 . Individual crabs probably spend a 

 fairly short time in the sound each year . 



4. An offshore migration is most 

 evident during September . 



5 . Tag recoveries indicate that there 

 is a fairly discrete population of horseshoe 

 crabs in Ipswich Bay. 



6. The techniques used to recover 

 tagged crabs were not adequate for an accurate 

 estimate of the population size. 



REIFEIEENCES 



Shuster, C. N., Jr. 



1950. III. Observations on the natural 



history of the American horseshoe 

 crab, Limulus polyphemus . 

 Third report of investigations of 

 methods of improving the shellfish 

 resources of Massachusetts . 

 Mass. Dept. Consv., Div. Mar. 

 Fish., pp. 18-23. (Also Woods 

 Hole Oceanographic Institute 

 Contr. No. 564.) 



Smith, O. R., andE. Chin 



1951. The effects of predation on soft 

 clams, Mya arenaria . 

 Conv. Add. Nat. Shell. Assoc. 

 1951, pp. 37-44. 



Turner, H. J., J. C. Ayers, andC. L. 

 Wheeler 

 1948. App. II. The horseshoe crab and 

 boring snail as factors limiting 

 the abundance of the soft -shell 

 clam. 



Report on investigations of the 

 propagation of the soft -shell clam, 

 Mya arenaria . 



Mass. Dept. Consv., CXv. Mar. 

 Fish., pp. 43-45. 

 (Also Woods Hole Oceanographic 

 Institute Contr . No. 162.) 



14 



