28 ILLINOIS BIOLOGICAL MONOGRAPHS [378 



The following species may be assigned with certainty to the genus 

 Anoplocephala. 



A. perfoliata Goeze A. magna Abildgaard 



(syn., A. plicata & A. zebrae) 

 A. globiceps Diesing A. mamillana Mehlis 



A. wimerosa Moniez A. variabilis Douthitt 



A. infrequens Douthitt 



The following species are not well enough known to allow of generic 

 determination, but should be left here for lack of better disposal. 

 A. inermis von Linstow A. blanchardi Moniez 



(syn., A. arvicolae) A. dentata Galli-Valerio 



A. omphalodes Hermann A. paronai Moniez 



A. rcstricta Railliet A. spatula von Linstow 



A. transversaria Krabbe 



Schizotaenia americana Stiles 1895 



[Figures 28, 29] 



Stiles in 1895 gave a short description of this cestode and placed 

 it in the genus Andrya. The next year he transferred it to the genus 

 Bertia, (now Bertiella). In 1906 von Janicki, having proposed the 

 genus Schizotaenia, included this form and Bertiella americana leporis 

 in that genus, basing his action mainly upon the distribution of testes, 

 since the description of Stiles was noncommittal or erroneous on other 

 points that might be of importance. The results of the present studies 

 justify completely von Janicki 's disposal. 



In 1906 Cohn expressed it as his opinion that this cestode was the 

 one described by Leidy (1855) as Taenia laticephala, and that the 

 specific name " americana Stiles" should be dropped as a synonym. 

 I cannot agree that the evidence justifies such a conclusion. With full 

 consideration for the ability of cestodes to contract and expand, it is 

 a severe strain on one's credulity to conceive how a cestode 1.3 inches 

 long and 2.8 lines broad could at will become 9 inches long, and % of 

 a line broad; and how a proglottid 12 times as broad as long could 

 become square. Moreover, Leidy states that the width of the neck in 

 the forms at his disposal is % of a line, or one-half the diameter of the 

 head. These specimens have no neck and strobilzation is very con- 

 spicuous even in the first proglottids. Leidy states that the anterior 

 proglottids are oblong-square. If this means that they were longer than 

 broad, we have a condition that is unprecedented in the Anoplocephali- 

 dae; if it means that they were broader than long, then Leidy 's speci- 



