HYDROMEDUSAE 



309 



Fig. 8. WilUa miitabilis. The radial canal system of an adult 

 having a stomach with six lobes. 



3 m 



Fig. 9. Willia mutabilis. The radial canal 

 system of an adult having a stomach with 

 seven lobes, but one lobe has two main canals. 



Fig. ID. Willia mutabilis. The radial canal 

 system of an adult having a stomach with five 

 lobes, four of which have two main canals. 



Fig. 1 1 . Willia mutabilis. A stomach with 

 five lobes, with one lobe enlarged and 

 having three main canals. 



Fig. 12. Willia mutabilis. A stomach with ten 

 lobes, arranged in a very irregular manner. 

 The canal system is also very irregular. 



