1908.] NATURAL SCIENCES OF PHILADELPHIA. 9 



the ordinary methods to determine the intelhgence of Sycotypiis and 

 Fulgur. The solution of this problem awaits some ingenious future 

 investigator. 



Summary. 



1. Fulgur and Sycotypus are very hardy and hve well in caiotivity. 



2. Fulgur probably attacks any Lamellibranch. 



3. Sycotypus will attack any except Venus. 



4. Oysters are eaten in less than an hour. Clams in from an hour 

 to an hour and a half. Quahogs from seven hours to three days. 



5. They do not bore shells with the radula. 



6. They open shells of oysters by wedging their own shell between 

 the valves, and tear out the flesh with their radula. They probably 

 treat Quahogs in the same way. 



7. Some shells are injured in the process, depending on the amount 

 of gap and the sensitiveness of the organism to mechanical stimuli. 



8. Their meals are far between. 



9. They spend their time between meals buried in the sand. 



10. They may not be as serious a pest to the oj^stermen as previously 

 reported. 



11. Their behavior is adaptive. As yet we have no proof that these 

 animals are intelligent. 



Literature. 



1S95. Cooke. Cambridge Xat Hist., Vol. Ill, p. 60. 



1905. DiMON, A. C. Cold Spring Harbor Monographs, V, pp. 31-36. 

 1890. Francois. Arch. E.rp.G., (2), IX,p. 2-0). 



1870. Gould. Invertebrata of Mass., 2d. ed., bj'^ W. G. Binney. 



1906. Herrick, J. C. jMeclianism of the Odontophoral apparatus in Sycotypus 

 canaliculatus, -tHK .Vo^, Vol. XL, p. 707. 



1884. Ingersoll, E. Fisheries Industries of the U. S., Section I, p. 694. 



1906. Jennings, H. S. Behavior of the Lower Organisms, p. 334. 



1907. Jennings, H. S. Behavior of the Starfish Asterias forreri, U. of Cal. Pub. 

 in Zool, Vol. IV, No. 2, p. 155. 



1860. Stimpson. Check List, p. 6. 



1882. Tryon, G. W. Structural and Systematic Conchology, p. 137. 



1905. Wilcox, M. A. Biology of Acmsea testudinahs. Am. Nat., May, 1905, 



p. 325. 

 r 



Description of Plates I-V. 



Figs. 1 and 2 were drawn with the aid of a camera lucida and magnified about 72 

 diameters. 



Figs. 3 and 4 were drawn with a camera lucida and magnified about 270 times. 



The succeeding figures were drawn free-hand from living animals with the 

 exception of figs. 7 and 8, which are semi-diagrammatic. They are f natural size. 



