579 



15. <i 



17. 



16. <! 



' Dorsal root longer Iban 

 prong- or ventral root; if 

 rostellum is armed there 

 are 24 to 30 hooks present; 

 senital pores unilateral 

 (on left of segments); 3 

 testicles normally pres- 

 ent in each segment; re- 

 tractile rostellum armed 

 with minute hooklets or 

 rudimentary and un- 

 armed; eggs with 3 en-, 

 velopes; parasitic in man, 

 chiroptera, insectivo'ra, 

 rodents, ■a.itil insectivior- 

 ous birds; larval stage in 

 insects or myrianoda, ... 



Hooks on suckers arranged 

 in circular rows on bor- 

 der; hooks on rostellum 

 resemble a hammer in 

 form and arranged in a 

 double row; with four ex- 

 ceptions knoT\'n only In 

 birds, 



Hooks on suckers ari-anged 

 in several transverse 

 rows; hooks of infundi- 

 bulum very small (4 u ) 

 arranged in a single row ; 

 known only in biids 



Hooks on suckers arranged 

 in one median set and 

 two lateral sets; hooks on 

 rostelluni' iprovidejd with 

 long dorsal root and ar- 

 ranged in a single row; 

 known only in birds, . . . 



Anterior extremity of stro- 

 bila expanded in form 



of a hammer 



\ Anterior segments become 



Icaliclform and function 

 as a pseudoscolex 



HYMENOLEPIS, p. 591 



DAVAINEA, p. 613 

 OPHRYOCOTYLE, p. 630 



ECHINOCOTYLE, p. 62S 



FIMBRIARIA, p. 636 

 INDIOGBNES, p. 637 



Family BOTHRIOOEPHALIDAE. 



Diagnosis: Head provided with two groove or slit-like suck- 

 ers; rostellum wanting; uterus with special pore; genital pores 

 generally (possibly always) dorsal or ventral. Type genus: 

 Bothriocephalus Rud.. 180S. 



