CESTODES 



199 



elongate and not in groups: in small intestine of sheep and cattle; often 

 common. 



M. expansa (Rudolphi) (Fig. 323). Body up to 4 m. long and 26 

 mm. wide, and often 

 quite thick; interpro- 

 glottidal glands a 

 straight row of round 

 sacs : in sheep, cattle, 

 deer, and goats ; com- 

 mon. 



5.THYSAN0S0MA 



Diesing. Segments broader than long with 



Fig. 323 — Moniezia expansa (Stiles). A, two segments; 

 B, end view of liead ; g,, interproglottidal glands. 



only on one side, and either 



324 — Thysanosoma actinoides (Stiles) 

 side view and ventral view ; B, segments. 



A, head, 



genital pores on both sides or 

 or 1 set of genital organs; a single uterus 

 in each segment con- 

 sisting of an undulat- 

 ing, transverse tube 

 with side pockets: 2 

 species, in sheep. 



T. actinoides Dies. 



The fringed tapeworm 



(Fig. 324). Length 



up to 30 cm.; width 8 mm.; head prominent; neck veiy flat and broad; 



binder margin of each segment fringed: common in the west. 



Family 2. DIPYLIDIIDAE. 



Scolex usually with hooks on a rostellum; uterus made 

 up of a large number of egg sacs, or it may be absent, in 

 which case the eggs are distributed throughout the par- 

 enchyma; larva a cysticercoid : in birds, mammals, and 

 reptiles; 10 genera. 



1. DiPYLiDiTJM Leuckart. Rostellum retractile and 

 with hooks; genital pores and organs double in each seg- 

 ment; uterus reticular: 1 species. 



D. caninum (L.) {D. cucumerinum Rudolphi) (Fig. 

 325). Length up to 25 cm.; breadth 3 mm.; ripe segments 

 about 7 mm. long and 3 mm. wide and often reddish in 

 color : in cats and dogs, and occasionally in young children ; 

 cysticercoid in the dog's flea; common. 



2. Hymenolepis* Weinland. Small filiform worms with broad seg- 

 ments with the genital pores all on the left and never on both sides; 



* See "An Account of the Tapeworms of the Genus Hymenolepis Parasitic in 

 Man," by B. H. Ransom, Bull. No. 18, Hyg. Lab., 1904. 



Fig. 325 

 DipyUdium 



caninum 

 (from Ward). 



