36 



SUB-KINGDOM (TYPE) IV.ANNULOSA. 



THE body is usually more or less elongated, and is always 

 bilaterally symmetrical, instead of being radially disposed. 

 Typically, the body is composed of morphologically similar 

 segments, which may be definite or indefinite, and which are 

 arranged along a longitudinal axis. Lateral appendages may 

 be absent or present, and when present are bilaterally dis- 

 posed. A nervous system is present, consisting, in the 

 lower forms, of one or two anteriorly-placed ganglia, but 

 having typically the form of a ventrally-placed, double, gang- 

 liated chain. 



DIVISION L SCOLECIDA. 



CLASS I. PLATYELMIA (Flat-worms). 



ORDER I. T^NIOIDEA (CESTOIDEA). 



Fam. a. Tjeniada. Tcenia (fig. 30). 



Fam. &. Bothriocephalidse (Dibothridae). Bothrioceph- 



alus. 



.Fam. c. Diphyllidse. Ecliindbothrium. 

 Fam. d. Tetraphyllidse. Phylldbothrium. 

 Fam. e. Tetrarhynchidse. Tetrarhynchus. 

 Fam. /. Ligulidse. Ligida. 

 Fam. g. Caryophyllseidse. CaryopJiyllceus. 



(Van Beneden, Les vers Cestoides, Mem. Acad. de Bruxelles, 1850 ; 

 Leuckart, Die Blasenbandwurmer und ihre Entwickelung, Giessen, 1856 ; 

 Spencer Cobbold, Entosoa, An Introduction to the Study of Helminthology, 

 1864.) 



