CESTODES 197 



4. Phyllobothrium van Beneden. Botliria sessile or nearly so, 

 with very convoluted edges and with an anterior accessory sucker; neck 

 very long: several species. 



P. f oliatum Linton. Length up to 18 cm. ; length of 

 tenninal segment about 1.4 mm., Avidth .9 mm. : often 

 numerous in spiral valve of the sting ray. 



5. EcHENEiBOTHRiUM van Beneden. Bothria stalked, 



elongate or oval, and very contractile, the face of each 



being subdivided by 1 or 2 longitudmal and several trans- ^coiex of 



EcJieneihothrium 

 verse septa ; myzorhynchus present but may be wanting in rariaWe 



old worms: several species. 



E. variabile v. Ben. (Fig. 319). Length about 10 cm.; neck long: 



in the spiral valve of the common skate; often common. 



Order 3. CYCLOPHYLLIDEA. 



Body usually elongate; scolex with 4 simple cup-shaped suckers, 

 between which a protrusile rostellum with hooks is usually present; 

 segmentation distinct; no uterine pore; common genital pore usually 

 marginal; yolk gland unpaired and usually behind the paired ovary: 10 

 families and about 50 genera which live principally in the higher verte- 

 brates; larva a cysticercus or cysticercoid, so far as known. 



Key to the families of Cyclophyllidea here described: 



Oi Uterus transverse in position and either tubular, sac-like, or reticulate. 



6i Scolex without hooks 1. Anoplocephalidae 



&2 Scolex with hooks. 



Ci No hooks in the suckers 2. Dipylidiidae 



Ca Suckers armed with hooks 3. Davaineidae 



flg Uterus consists of a median stem and side branches 4. T^niidae 



Family 1. ANOPLOCEPHALIDAE.* 



Scolex more or less spherical, without hooks but with large suckers) 

 segments short and wide; uterus transverse in position and tubular, sac- 

 like, or reticular: in mammals; 8 genera. 



Key to the genera of Anoplocephalidae here described : 



Oi Genital pore on but one side of the segment. 



&i Genital pores on the same side of all the segments 1. Anoplocephala 



62 Genital pores regularly or irregularly alternate 2. Bertia 



02 Genital pores on both sides of the segment. 



&i Uterus reticulate and double 4. Moniezia 



&2 Uterus tubular. 



Cx Uterus a thick tube, single or double : in rodents 3. CiTTOTiENiA 



c. Uterus undulate : in sheep 5. Thysanosoma 



♦ See "A Revision of the Adult Tapeworms of Hares and Rabbits," by C. W. 

 Stiles, Proc. U. S. Nat. Mus., Vol. 19, p. 145, 1S9G. 



