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 Uebersetsungsrecht vorbehalten. 



On the American Representatives of Distomum 

 variegatum. 



By 



J. StaflFord, B. A., Ph. D., 



Zool. Lab., McGill Univ., Montreal, Canada. 



With plate 33. 



I. Creneral. 



As knowledge of faunistic helminthology widens, it becomes 

 increasingly apparent that, in many cases, the conception of a species 

 of the older investigators must, in the future, be broadened to include 

 a group of closely-related forms. One has but to think of such 

 species as Distomum appendiciilatum, of fishes, and Distomum cygnoides, 

 of amphibia, and of many conflicting Statements in the literature to 

 understand what confusion is likely to arise by a too-fervent anti- 

 pathy towards increasing the number of specific terms. 



Distomum variegatum Rud., from the lungs of anurous amphibia, 

 is another of the original species that has to be resolved into a 

 group of modern species. Its history dates back to Zeder's Erster 

 Nachtrag zur Naturgeschichte der Eingeweidewürmer, Leipzig, 1800; 

 its name dates from Rudolphi's Entozoorum Synopsis, Berolini, 1819. 

 Bremsee, Ckeplin, Dujardin, Blanchard, Diesing, Pagenstecher 

 and others have had their turn in working out its anatomy and life- 

 history. A modern and most thorough account of it is to be found 

 in the large volume by Looss: Die Distomen unserer Fische und 



