64 ILLINOIS BIOLOGICAL MONOGRAPHS [414 



saclike. Development usually by outpocketing, the uterus 

 rarely breaking up into separate compartments, never with 

 paruterine organs. Vitelline and shell glands always pres- 

 ent -Anoplocephalinae 2 



Uterus breaks down early into egg capsules. Genital canals 

 pass ventral to excretory ducts or between them. Cortical 

 parenchyma usually very thick. A single set of reproduct- 

 ive organs in each segment in all known species. Vitelline 

 and shell glands always present Linstowinae 51 



Paruterine organs present. Genital canals pass between the 

 excretory vessels and dorsal to the nerve. Embryos with 

 two shells, usually with pyriform apparatus which is de- 

 void of horns. Testes in two lateral groups which cross 

 the excretory ducts on either side. Vitelline and shell 

 glands present Thysanosominae 70 



Paruterine organs present. Genital canals pass dorsal to excre- 

 cretory ducts or between them. Eggs with two shells, no 

 pyriform apparatus. No vitelline gland or shell gland. 

 All known species inhabit ruminants. (See Gough, 1911.) 



Avitellininae 71 



Anoplocephalinae 



2. Without genital pores. Testes crossing excretory ducts on both 



sides of the proglottid. No pyriform apparatus. One genus 



and species. (See Fuhrmann, 1902.) Aporina alba 



With genital pores. Testes not crossing excretory ducts on 

 pore side — 3 



3. With not more than one cirrus pouch in each lateral half of the 



segment. With numerous testes. With external evidences 



of segmentation 4 



With four or five cirrus pouches in each lateral half of the 

 segment. With but one testis in each lateral half of the 

 segment. Without external evidences of segmentation. One 

 genus and species. (See von Janicki, 1906.) 



Triplotaenia mirabilis 



4. With but one set of reproductive organs in each proglottid _.~ 5 



With two sets of reproductive organs in each proglottid — 6 



5. Vaginal pore posterior to cirrus pouch. Uterus reticular. 



Either with a pedunculated prostate gland or with ventral 

 excretory ducts enormously developed. Genital pores all, 

 or nearly all dextral. (See present paper.) Andrya 7 



