7IO maccallum. 



DESCRIPTION OF PLATE XXXIX. 



Fig. I. Clinostomum heterostomum — adult seen from ventral surface; ci., 

 cirrus sac ; ov., ovary ; ex., excretory vesicle ; t.t., testes ; go., opening of uterine 

 tract ; «., uterine sac ; vit., yolk gland. 



Fig. 2. Female genital apparatus, seen from dorsal surface ; Lc, Laurer's 

 canal ; od., oviduct ; yd., yolk ducts ; yr., yolk reservoir. 



Fig. 3. Cirrus (from ventral surface) ; v.e., vasa efferentia ; s, sac containing 

 spermatozoa ; c, muscular tube ; /, extrusible portion opening at external genital 

 pore ; go., external female genital pore. 



Fig. 4. Scheme of nervous system ; nervous system in blue, alimentary tract 

 in red. 



Fig. 5. Parenchyma cells in anterior portion of the body, with strands of body 

 musculature. 



Fig. 6. Intestinal coeca in longitudinal section. 



Fig. 7. Genital apparatus of immature form (D. gracile, etc.). 



