Introduction to A 7itmal Morphology, 1 7 1 



phalus, found in Teleostean fishes. Pterobothrium inhabits^ 

 Trichiurus. Phyllacanthinas have the suckers each armed 

 with 2-4 hooks. Acanthobothrium is a fish parasite. 

 Family 5. Ligulidoe — body only weakly transversely striped ; 

 head not separate ; suckers, 2, developed late ; middle 

 of the body with a long furrow. The series of medio- 

 ventral sexual organs alone indicates the number of compo- 

 nent metameres. The proscoleces resemble those of Both- 

 riocephalus. Some multiply by buds, and their immature 

 forms are found in fish, their perfect forms in fish and water 

 fowl ; some are viviparous. They are found often in the 

 peritoneal cavities of carp, minnows and sticklebacks. Family 

 6. Caryophyllaeidae — body flat, unjointed, of one proglottis ; 

 fimbriated or sub-globose in front ; a transverse, two-lipped 

 sucker lies at the front end ; the body consists of a sexual 

 and an asexual (anterior) part ; both sexes may have their 

 organs opening together medio-ventrally, or the penis may 

 be anterior; evolution is direct. Caryophyllaeus mutabilis is 

 found in the carp. C. punctulatus in the conger ; Eustemma, 

 in Falco pileatus, has the female opening on a sub-conical, 

 retractile eminence ; Monobothrium and Diporus in fishes. 

 Family 7. Amphilinidae — one-jointed parasites ; passage forms 

 to the next order, placed here as they have no trace of a di- 

 gestive canal, except an anterior muscular caecum (a modified 

 sucker (?) or rudimental pharynx) ; with a single sucker and 

 branched water-vascular system, and the oviduct opening 

 near the head. The development resembles that of Trema- 

 todes, ex. Amphiline, Amphiptyches. Gyrocotyle, from the 

 pygarg, has a gyrately-folded sucker and a dorsal pore to the 

 water-vascular system ; in some points it seems to be related 

 to Malacobdella. Diesing places these in the next, Wagener 

 in this order. 



