no ILLIXOIS BIOLOGICAL MONOGRAPHS [390 



EXPLANATION OF PLATE 



Alassostoma magnum 

 Fig. 59- Entire specimen, ventral view. X 9. 

 Fig. 6o. Cross section thru the genital pore showing the terminal parts of the 



cirrus sac and uterus, the hemaphroditic duct, genital sinus, four 



layers of muscles in the body wall and the muscle lamellae of the 



esophageal bulb. X27. 

 Fig. 61. Diagrammatic representation of female genital apparatus reconstructed 



from cross sections. X40. 

 Fig. 62. Section of the wall of the intestine. X36o- 



Fig. 63. Cross section thru the oral sucker and the oral evaginations. X 4°- 

 Fig. 64. Cross section of body at the level of the ovary showing in section the 



ovary, uterus, Laurer's canal, the ceca, vitellaria, lymph spaces and 



excretory ducts. X 16. 

 Fig. 65. Cross section thru the oral sucker showing arrangement of muscle fibers 



and position of the nuclear zone. X 35- 



