413] ANOPLOCEPHALIDAE— DOUTHITT 63 



KEY TO KNOWN SPECIES OF ANOPLOCEPHALIDAE 



Owing to the fact that the literature of this group is scattered, 

 uncoordinated, and often inaccessible, the task of identifying material is 

 often very difficult and time-consuming. The writer in taking up for 

 the first time the several groups here studied, has had good cause to 

 realize this. In the hope that it will spare to others this waste of labor 

 in becoming acquainted with the field, the following key to all the 

 known species of Anoplocephalidae is presented. A great many poorly 

 described species are represented here, species as to whose affinities no 

 one has any means of judging. In order to avoid confusion they are 

 left in the genera to which they have been assigned, tho in many cases 

 there is no proof that they belong even in the family. To prepare a 

 key for such species has been found very difficult and in some cases the 

 only thing that could be done was to list them with such descriptions 

 as are possible. 



In order not to hamper the serviceableness of the key only the more 

 important synonyms are given and usually only the best reference is 

 given for each species. For an exhaustive bibliographic account of the 

 various species and genera, the reader is referred to Stiles & HassalTs 

 excellent summary (1912). True phylogenetic characters have been 

 used wherever possible ; and wherever such exist, classifications pre- 

 viously proposed have been accepted. No attempt has been made to 

 treat the Linstowinae critically ; they are included here merely to make 

 the key complete and critical study is left to someone better fitted to 

 take up the work. 



Family Anoplocephalidae : Scolex and suckers unarmed. Seg- 

 ments nearly always broader than long, generally many 

 times broader than long. Genital pores marginal (absent 

 in Aporina). Testes numerous, except in Triplotaenia. 

 Uterus transverse. Embryos with thin, transparent shells, 

 usually with a pyriform apparatus borne upon the inner- 

 most shell. Adults in mammals and birds, mostly in her- 

 bivorous mammals; larval stages unknown. Four sub- 

 families 1 



1. Genital canals dorsal to longitudinal excretory vessels and 

 nerves, except possibly in Triplotaenia, and in some pro- 

 glottids in some Schizotaenia. Uterus at the stage of sexual 

 maturity tubular, netlike, or diffuse, or, in Triplotaenia, 



