1901.] NATURAL SCIENCES OF PHILADELPHIA. 657 



ZYGEUPOLIA LITORALIS, A NEW HETERONEMERTEAN. 

 BY CAROLINE BURLING THOMPSON, PH.IX 



I. Introduction. 



At the end of August, 1899, four specimens of Zygeupolia litor- 

 alis were discovered by the writer at Wood's Hole, Mass. The 

 following summer the worms wei'e found in great abundance in the 

 same locality, and from fifty to one hundred specimens were 

 obtained. 



The work on this paper has been mostly done in the Zoological 

 Laboratory of the University of Pennsylvania, under the direction 

 of Prof. E. G. Conklin and Asst. Prof. T. H. Montgomery, Jr., 

 and it is a pleasure to express my thanks to both for their interest 



^ Contribution from' the Zoological Laboratory of the University of 

 Pennsylvania. 



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