On Aspidogaster ringens (Linton) and A. kemostoma ii. sp. 



247 



marginal suckers and only sixteen grooves. In many cases, however, 

 there is an unpaired anterior and posterior sucker in tliis marginal 



Fig. A. 



Fig. B. 



Fig. A. AaiMogaster ringens (seen from below). The drawing shows the 

 indistinct central ridge in the sucking disc and the regularly arranged tactile 

 bodies between the margin and suckers. 



Fig. B. Aspidogaster ringens. a Viewed from the side. M mouth opening. 

 i) intestinal ceciun. GrO common genital opening. FS seminal vesicle. DG ducts 

 irom vitellarium. LC Laurer's canal. R single testicle. SD shell gl and. b en- 

 larged sketch of female genitalia. Letters as above. A ovary. 



row and with brilliant Illumination tliere can sometimes be seen a 

 partial or complete median longitudinal ridge. It is difficult to 



