848 WINTERTON C. CURTIS 
SUMMARY 
Experimental infections of the sand shark (Carcharias littor- 
alis) with the cestode larva known as the Scolex polymorphus 
indicate that the larvae used for these experiments developed into 
the species Phoreiobothrium triloculatum. It seems clear that 
the common tapeworm (Crossobothrium laciniatum) of this 
shark cannot come from the Scolex polymorphus, even though 
this larval type may represent the young of a number of cestodes, 
a possibility which is referred to in the third section of this paper. 
Starving the sharks had no effect upon the cestodes, but by 
means of treatment with the oil of male fern followed by calomel. 
the great majority of the parasites wese eliminated before the 
sharks were artificially infected. It seems probable that by a 
little more experimentation a method of treatment could be 
secured, which, for eliminating these parasites, would be suffi- 
ciently effective for all working purposes. 
