70 COLLINGE : ON THE ANATOMY OK THE VITKINA IRRADIANS. 



EXl'LANATION OF PLATES V AND VI. 



Fig. I. 



Fig. 2. 



rig- 5- 



Fig. 4. 



Fisf. 



Fig. 6. 



Ral)iadvipia iyradians. I'fr. 



Intestinal tract. 



Generative organs, x \\. 



Dissection of the vagina and free-oviduct to show the internal walls. 



Dissection of the terminal ducts of the male generative organs, showing 



evertible penis, lumen of the diverticulum and plicae of the 



epiphallus. 

 Terminal ducts of the male generative organs of a young specimen, 



showing the penis everted, and the short epiphallus. x 25. 

 Terminal ducts of the male generative organs of a fully matured 



specimen, showing variation in the epiphallus. 

 Spicule from the kalk-sac. x 4. 

 Calcareous granules from the kalk-sac. 

 Dart-sac opened to show the fleshy dart. 

 Transverse section of the dart-gland. 

 Epithelial layer of the dart-sac. 

 The free muscles. 

 The pallial complex. x i^. 



Reference Letters. 



