578 



10. 



' Kg'gs with thin transparent 

 shells; frequently in egg 

 eapsules, in some cases 

 scattered through the 

 segment; head nearly al- 

 ways armed with hoo In- 

 lets on rostellum; larvil 

 stage a cystlcercoid; 

 adults in birds and mam- 

 mals 



i Suckers unarmed. 

 I Suckers aimed with min- 

 { ute hooklets (with four 

 j exceptions known only in 

 i birds) 



11. 



(' Genital pores double 



i Genital pores single, ir- 



I regularly alternate or un- 



l. ilateral 



A 



Two submedian ovaries in 



22 J each segment 



One median ovary in each 

 segment, 



13 



( Several i-ows of hooks upon 



j rostellum 



1 A single row of hooks upvn 

 (. rostellum, 



{ Dorsall root of hook much 

 longer than ventral loot 

 or prong; ventral root 

 very short; hooks 8 to 12 

 H. { rarely to 26) in number; 

 known only in birds, .... 

 Dorsal root of hooks about 

 the same length as ven- 

 l tral root and prong, ... 



' Dorsal ^root shorter than 

 prong or ventral root; 

 hooks generally less than 

 20 in number (range from 

 10 to 26); genital pores 

 vmilateral or irregularly 

 alternate; known only in 

 birds 



15. { 



DIPYLIDIINAE, p. 58.5 



p. 586 



p. 587 



p. 585 



p. 586 

 AMABILIA, p. 588 



DIPYLIDIUM, p. 586 

 COTLTGNIA, p. 586 



DREPANIDOTAENIA. p. i}97 

 p. 591 



DICRANOTAENIA, p. 591 



lAs the terms anterior and posterior in referring to the roots 

 of the hooks are reversed by some authors. 1 suggest the use 

 of the words dorsal and ventral in their place. These words 

 are not open to misinterpretation, the dorsal root being a con- 

 tinuation of the dorsum of the prong; the ventral root lies 

 under the prong. 



