figures li;m' ln'cii ((iiLsiiKud as far a.s pusKililf aiiij dala 

 derived Irniii lliciii luno l)coii (■(niiliin.'d wiili iiioiv re 

 cent diiif^uoses and descriptions. 



It would be well if authors iiiaUin^ and iiiililishinj; 

 specific determinations in this grouj) would preserve 

 I heir specimens in some way, so that they may be used 

 by later writers on the subject, for in many of the 

 species described below the determination can be 

 looked upon only as approximate and provisional. 

 'J'he si)e(ific determination of these forms is of much 

 {greater importance from a practical standpoint than 

 is fjenerally assumed, for an exact knowledge of the 

 s])ecies is necessary as a f<iunda(ion for {general pre- 

 ventive measures. 



Nomenclature.^In several ])laces where it is per- 

 fectly evident (hat the parasites are now sailing under 

 wrong names, I have corrected the names according \i> 

 (he international rules. In the majority of cases, hmv 

 ever, I postpone changes until I can complete a revi 

 sion of the entire group based upon original material. 



In the systematic arrangement given below keys are 

 given not only to (he species of adult tapeworms n.f 

 domesdc fowls, but also to some closely allied forms. 

 The allied genera and subfamilies are given in (he 

 keys in order (o show (he general relationships of (he 

 group. 



The tapeworms of fowls belong to two families, the 

 Hothriocephalidae and Taeniidae. 



Regarding the gener-ic i)Osition of the tapeworms of 

 domesiicated fcwls it may be stated that np (o witliin 

 very recent years nearly all of the forms have been 

 ))laned in the collective genus Taenia. To R, P.hiii 

 chard and A. Railliet is due the chief credit of ])ointing 

 out the absnrdi(y of uniting these forms genericnlly 



