THE SKATE. 



55 



7/y.s 



FIG. 18. Raja batis. The urinogenital organs of the male (one- 

 third nat. size). 



The organs are supposed to be removed from the body along with a 

 small portion of the oesophagus (ces), and viewed from the ventral aspect : 

 the right testis (t) is removed, along with the corresponding epididyniis 

 (epd) and all but the posterior extremity of the vas deferens (v.d), 

 which, with the sperm sac (s.s) is turned outwards to display the 

 ureters (ur) : the cloaca (cl), the urinogenital sinus (ug.s), and the 

 right vesicula seminalis (v.s) and sperm sac (s.s) are laid open. 



a.p, abdominal pore : cl, cloaca : epd, epididyniis : i.r, inter-renal 

 body : k, kidney : ces, oesophagus : pn.d, pronephric duct : s.s, sperm 

 sac : s.s', its opening into the urinogenital sinus : t, testis : ug.p, urino- 

 genital papilla: ug.s, urinogenital sinus: ur, ureter: ur 1 , its opening 

 into the urinogenital sinus: v.d, vas deferens: v.s, vesicula seminalis : 

 z/./, its opening into the sperm sac. 



