234 THE ANIMAL PARASITES OF MAX 



THE TREMATODES OBSERVED IN MAN. 

 Family. Paramphistomidae, Stiles and Goldberger, emend. 1910. 



Sub-family. Cladorchiinae, Fisch., 1901. 

 Genus. Watsonius, Stiles and Goldberger, 1910. 



Cladorchin<z.Rvfrj pyriform. Ventral pouch absent. Acetabulum ventral or 

 (?) ventro-subterminal, very large, margins projecting, aperture small. Genital 

 pore in front of bifurcation of gut, not surrounded by a sucker ; ductus herma- 

 phroditicus apparently absent. Excretory pore at posterior end of excretory vesicle, 

 behind Laurer's canal. Oral sucker with a pair of irregularly globular suctorial 

 pouches ; cesophagus thickened distally ; caeca long, not wavy ; end in acetabular 

 region. 



Male Organs. Testes two lobed, smaller than acetabulum ; longitudinally, 

 nearly or quite coinciding ; transversely they abut or slightly overlap ; preovarial 

 in equatorial and caudal thirds. Pars musculosa not largely developed; cirrus 

 pouch absent. 



Female Organs. Ovary and shell gland post-testicular. Vitellaria extend from 

 gut fork to slightly beyond gut ending ; uterus intercaecal, partly post-testicular. 

 Laurer's canal in front of excretory vesicle. 



Type Species. Watsonius watsoni, Conyngham, 1904. 



Watsonius watsoni, Stiles and Goldberger, 1910. 

 Syn. : Amphistommn watsoni, Conyngham, 1904; Cladorchis watsoni, Shipley, I95* 



Body, 8 to io mm. long, by 4 to 5 mm. broad, by 4 mm. thick ; tapers 

 anteriorly to 2*5 mm. Caudal extremity bluntly rounded, venter 

 surrounded by an elevated ridge, surface with 

 / ^^5J\ transverse ridges best defined ventrally. Genital 



if 3\ pore median about one-quarter of body length 



i/ : \\ from anterior end at level of suctorial pouches. 



%\ Acetabulum i mm. in diameter, margin project- 

 ing, aperture small. Mouth in a groove with 

 digitate papillae. Oral sucker very large, one-fifth 

 of length of body, with a pair of irregularly 

 SI globular pouches. (Esophagus somewhat longer 

 than sucker. Excretory pore at the level of 

 the acetabular aperture. The vesicle extends 

 from the plane of the transverse vitelline ducts 

 FIG. 136. Watsonius to centre of acetabulum. 



watsoni: ventral view. ,, . ~ . . . 



4/1. (After Shipley.) Male Organs. Testes deeply notched adjoining 



one another. Vesicula seminalis much coiled 



and dilated, pars musculosa not coiled. Pars prostatica (?) dilated, 

 ejaculatory duct long and narrow, opening on a papilla ; genital 

 atrium papillated. 



