126 INVERTEBRATE ZOOLOGY 



b. Suborder Monostomata. — No ventral sucker. Notocotylus, 

 Cyclocoeliim. 



c. Suborder Strigeata. — Usually two suckers; cercaria fork- 

 tailed. Slrigca, SchistDHoma 



d. Suborder Amphistomata. — Acetabulum terminal or sub- 

 terminal, highly developed, posterior to reproductive organs. 

 Gastrodiscus, Diplodiscus, Allassostoma, Watsonius. 



e. Suborder Distomata. — Oral and ventral sucker present; 

 acetabulum usually anterior to reproductive organs. FasciaLa, 

 Fasciolopsis, Opisthorchis, Paragonimus, Clonorchis, Telorchis, 

 Pneumonoeces. 



m. Class Cestoda. — Parasitic; body covering a cuticula; no digestive 

 system; scolex for attachment. 



a. Subclass Cestodaria. — Body not divided into proglottids; a single 



set of reproductive organs. Gyrocotyle, Archigetcs, Amphilina, 



Caryophyllaeus, Glaridacris. 



h. Subclass Cestoda. — Body usually divided into proglottids; 



reproductive organs oft repeated. 



1. Order Pseudophyllidea. — One terminal or two opposite sucking 

 grooves. Abothrium, Bothriocephalus, Diphyllobothrium, Sparga- 

 num, Marsipometra; Ligida, Cyathocephalus, Triaenophorus. 



2. Order Trypanorhyncha. — Two or four suckers and four hook- 

 covered protrusible proboscides on scolex. Tetrarhynchus. 



3. Order Tetraphyllidea. — Four sucking cups; in fish and reptiles. 

 Dinobothriu m, Proteocephalus, Corallobothrium. 



4. Order Cyclophyllidea. — Four cuplike suckers and an apical 

 organ of varied form. Taenia, Hymenolepis, Echinococcus, Ana- 

 plocephala, Dipylidium, Davainea. 



IV. Class Nemertinea. — Ciliated; proboscis and proboscis sheath, 

 dorsal to mouth; blood system; digestive canal complete; aquatic. 



1. Order Protonemertini. — Nervous system outside the muscles; 

 no stylet. Carindla. 



2. Order Mesonemertini. — Nervous system in muscles; no stylet. 

 Cephalothrix. 



3. Order Metanemertini. — Nervous system inside muscles; usually 

 with stylets. Stichostcynma, Geonemertes. 



4. Order Heteronemertini. — Several layers of muscles; nervous 

 system in muscles; no stylet. Lineus, Cerebratalus. 



References 



(See general references cited at close of Chapter I) 

 Chandler, A. C. 1930. "Introduction to Human Parasitology." New 



York, Wiley. 

 Child, C. M. 1915. "Senescence and Rejuvenescence." Universitj^ of 



Chicago Press. 

 Curtis, W. C. 1902. The Life History, the Normal Fission, and the 



Reproductive Organs of Planaria maculata. Proc. Boston Hoc. Nat. 



Hist., 30: 515-559. 



