602 



CESTOIDEA 



The following tables, modified froni Stiles, may be of help, as 

 they give the names of recognition of the genera, and the species of 

 Tcenia, as determined by the head or the segment, and also a scheme 

 for recognizing the eggs. 



Table of Genera. 



A. Head with two elongated or slit-like suckers; uterus forms a rosette; 



genital pores ventral — DihothnocephalidcB . 



I. Tapeworms. — Single set of genital and uterine pores present in 

 medium ventral line — Dibothriocephalus. 



Double set of uterine and genital pores present in ventro- 

 submedium lines — Diplogonoporus . 



II. Plerocercoids {Sparganum) . — Probably larval forms of this group. 



B. Head with four cup-shaped suckers ; uterus does not form a rosette ; 



genital pores lateral — TcBniidcB. 



I. Large forms, ripe segments 9 to 35 millimetres long. Uterus 

 median, with lateral branches — Tcsnia. 



II. Smaller forms, ripe segments up to 7 millimetres long. 



[a] Genital pores single, rostellum with no more than two hooks. 



(1) Suckers not armed. Three testes in each segment— 



Hymenolepis. 



(2) ' Suckers armed with hooks, 15 to 50 testes in each 



segment — Davainea. 

 {b) Genital pores double, rostellum with several rows of hooks- — ■ 

 Dipylidium. 



Table of the Species of Taenia found in Man. 



A. Specimen is a Tapeworm. 



Head Characters. 



I. Head armed with hooks. Snhgenus : Tcsnia. S-pecies: T. solium. 

 II. Head unarmed. Subgenus: Tceniarhynchus. 



(1) Circular ring around head behind the suckers, which are 



directed posterio-anteriorly- — T. hominis. 



(2) Without circular ring. 



{a) Head cuboid, i*5 to 2 millimetres in diameter; suckers 

 o*7 to 0'8 millimetre in transverse diameter — 

 T. saginata. 



ip) Head small, 1*38 millimetres broad, 1*03 millimetres 

 thick, 0-47 millimetre long; suckers 0'63 millimetre 

 in transverse diameter — T. africana. 



[c) Head small cuboid, i to 1*5 millimetres in diameter, 

 0-75 millimetre thick, and i millimetre long; suckers 

 0'34 to 0'37 millimetre in transverse diameter — 

 T. philippina. 



III. Head not known — T. confusa, T. hvemneri. 



Segment Characters. 



I. Segment Longer than Broad, 

 [a) Only in the last 100 segments- — T. saginata. 

 \h) In the last half of the worm — T. solium. 

 (c) In nearly the entire worm — T. confusa. 

 \d) In the entire worm— T. africana. 



{e) Known segments very large, 28*6 by 8-5 millimetres on an average — 



T. hremneri. 

 (/) Unknown. — T. hominis. 



