no. 1817. 



A NEW TREMATODE—GOLDBERGER. 



235 



INTERNAL ANATOMY. 



Digestive tract. — The oral aperture is ventro-terminal in position, 

 circular in outline, and somewhat larger than the aperture of the 

 acetabulum. It leads into a well-developed oral sucker. The latter, 

 measured in sections, varies between 0.420 and 0.435 mm. in maxi- 

 mum longtidudinal, 0.300 and 0.315 mm. in maximum dorso-ventral, 

 and between 0.300 and 0.360 mm. in maximum transverse diameter. 

 It is therefore somewhat larger than the acetabulum. Its structure 



i'OyUs 



Fig. 2. — Sagittal section to show prepharyngeal atrium, p. ph., 

 prepharynx. (For other lettering see fig. 1.) Enlarged. 

 Original. 



is of the same loose-meshed character as the acetabulum. Attached 

 to the base of the oral sucker is a relatively roomy prepharyngeal 

 atrium or prepharynx (fig. 2) . This is succeeded by a pharynx that 

 measures about 0.105 mm. in longitudinal diameter. Around the 

 base of the latter is an accumulation of gland cells. In its turn the 

 pharynx is succeeded by an esophagus that forks laterally into the 

 intestinal ceca at a point just cephalad of the level of the genital pore. 

 The intestinal ceca pass caudad paralleling the lateral body margins, 

 to terminate in slightly separate planes at about the level of junction 



