PROCEEDINGS OF THE UNITED STATES NATIONAL MUSEUM 



haued l^^fVvi, 0?!^ hy the 



SMITHSONIAN INSTITUTION 

 U. S. NATIONAL MUSEUM 



Vol.89 Waihington: 1940 No. 3101 



THE POLYCLAD FLATWORMS OF THE ATLANTIC COAST 

 OF THE UNITED STATES AND CANADA 



By LiBBiE H. Hyman 



Since the work of Girard and Verrill and the one paper by Wheeler 

 in 1894, the polyclads of the Atlantic coast of North America have 

 not been studied until recently, when the subject was simultaneously 

 and independently attacked by Dr. A. S. Pearse, of Duke University, 

 and myself. Pearse and his associates ^ published their work in three 

 papers appearing in rapid succession which antedated my article on 

 some of the same species (Hyman, 1939a) . More recently I undertook 

 this revision of all the Atlantic coast material contained in the collec- 

 tions of the United States National Museum, including the polyclads 

 studied by Pearse, Littler, and Walker. Dr. Pearse himself furnished 

 me with two shipments of live polyclads. 



In the hope of discovering whole mounts mentioned by Verrill in 

 his account of New England polyclads (1892-93), I made a trip to 

 the Peabody Museum of Yale University and examined large numbers 

 of Verrill's slides. Nothing of value, however, was discovered. 

 Thanks are expressed to M. D. Burkenroad, assistant curator, for 

 time and trouble expended in helping me with these slides. 



The work of Pearse and his coworkers was based on whole mounts. 

 These have now been studied in serial section, except in the case of 

 one specimen, of which only the type was available. Unfortunately, 

 Pearse's specimens were found to be in extremely bad histological 

 condition, so that the sections were often unsatisfactory. It has 

 nevertheless been possible to determine the status of practically every 

 species. 



1 Pearse, 1938 ; Pearse and Littler, 1938 ; and Pearse and Walker, 1939. 



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