66 BULLETIN 69, UNITED STATES NATIONAL MUSEUM. 



SuTofaiDLily TIIYS^^:N"OSO]yLII^.2E Fiahrmann, ISOr. 



Subfamily diagnosis. — Anoplocephalidse : Uterus transversely elon- 

 gated consisting of several or numerous communicating sacs with 

 parenchymatous para-uterine organs, into which the eggs probably 

 pass in the oldest segments. Adults in mammals. 



Type-genus. — Thysanosoma Diesing, 1835. 



Genus THYSANOSOMA Diesing, 183S. 



Genenc diagnosis. — Thysanosominae : Segments much broader than 

 long, end segments only showing a tendency to become longer and 

 narrower. A double set of reproductive organs but only a single 

 uterus in each segment, with opposite or with irregularly alternating- 

 pores, those of one side, with the corresponding cirrus pouch, ovary, 

 and vagina having been suppressed. Genital canals pass between the 

 longitudinal excretory vessels, and dorsal of the nerve. Uterus trans- 

 verse, undulating, composed of numerous ascon-like pouches each 

 supplied with a parauterine organ. Horns of pyriform apparatus 

 absent. Adults in mammals (ruminants). 



Type-species. — Thysanosoma actinioides Diesing, 1835. 



Family DAVAINEID.E Fuhrmann, 1907. 



Family diagnosis. — Tsenioidea: Scolex with simple rostellum, 

 armed with double row (rarely a single row) of very numerous (and 

 generally very small) hammer-shaped hooks. Suckers armed or, 

 rarely, unarmed. A single or double set of reproductive organs in 

 each segment. Genital pores marginal, and bilateral, unilateral, or 

 irregularly alternating. Uterus sac-like, persistent; or sac-like or 

 branched, not persistent, replaced either by numerous 2gg capsules, 

 or by a single o^gg capsule whose formation is preceded by the appear- 

 ance of a para-uterine organ. Egg with thin transparent shells. 

 Adults in mammals and birds. 



Type-species. — Davainea Blanchard and E-ailliet, 1891. 



SuTofaiTiily 0]PH:RYOCOT^'ILiI]Sr.S: FuhrixiarLn, lOOT'. 



Suhfamily diagnosis. — Davaineidse : Rostellum," very broad, armed 

 with a double row of hooks on border. Surface of suckers armed 

 only near the anterior border, A single set of reproductive organs 



« Fuhrmann (1908a, p. 41) has found that the apical structure, with five de- 

 pressions, which has been described in different species of Ophryoeotyle, is really 

 a rostellum with an anterior enlargement which in certain stages of contraction 

 presents the peculiar appearance noticed by various authors. 



