TREMATODES 



187 



Fig. 306 — Microphallus 

 opacus (Ward). 



References 

 as in Fig. 293. 



H. occidualis Stafford. Body G mm. long; 1.5 mm. wide; testes in 

 oblique plane near acetabulum: in the mouth of frogs. 



15. Hemiurtjs Rudolphi. Small, cylindrical wonns, the hinder end 

 of whose bodies forms an appendix which can 

 be invaginated; cuticula transversely striped; 

 yolk glands compact, behind ovaiy, which is just 

 behind the testes: in fish. 



H. appendiculatus (Rud.). Appendix from 

 a third to twice the length of the body; acetabu- 

 lum much larger than oral sucker; yolk glands 

 spherical; 6 mm. long: in digestive tube of her- 

 ring and other marine fish; intermediate host 

 usually copepods. 



16. Clinostomum Leidy. Elongated worms 

 with mouth surrounded by a circular ridge ; ovary 

 between the testes in middle of body; intestine 

 without phaiynx and with side projections: in 

 mouth of birds ; about 10 species. 



C. marginatum (Rudolphi) (Fig. 307). Body 6 to 10 

 1 to 2 mm. wide; yolk glands voluminous: in Ardea and other birds; 

 intermediate host, the 

 sunfish and other fishes. 

 17. Schistosoma 

 "Weinland. Sexes sepa- 

 rate; acetabulum near 

 front end; male is larger than the 

 female and has a deep groove in 

 its ventral side in which the fili- 

 form female lies: several species, 

 in blood of mammals in tropical 

 countries. 



S. haematobium (Bilharz) 

 (Fig. 308). Body cylindrical; 

 length of male 14 mm.; length of 

 female 20 mm.: in the blood of 

 man, chiefly in Africa, occasionally 

 in this country. 



Fig. 307 



Clinostomum 



marginatum 



(Osborn). 



References 



as in Fig. 293. 



Division 4. HOLOSTOMATA. 



Fig. 308 

 Schistosoma 

 hcematohium 



(Looss). 

 1, oral sucker ; 



2, acetabulum ; 



3, male individ- 

 ual ; 4, female 

 individual. 



Digenetic trematodes with an oral sucker and an acetabulum, and 

 in addition a large variously constructed adhesive ventral disc or pro- 



