400 



FISHES 



m.Ti, 



Fig. 230. — Showing the principal modifications of the liidneys and reproductive organs 

 iu Cyclostomes and Fishes. A, The pronephros and its duct in the embryo ; 

 B, the liidneys and genital pores in Petromyzon, the vestigial jironephros repre- 

 sented as in Myxine; C and D, the urinogenital organs of a male and female 

 Elasmobranch ; E, of a male or female Teleost, or a male Lepidosteits ; F, of a 

 female Pnli/pteriis, Acipenser, Amia, or Osmerus. a. Anus ; a.d, archinephrio 

 duct ; c, cloaca ; c.a, the coelomic aperture of the Mtillerian duct ; c.p, cutaneous 

 pit ; <jf, gonad ; gd, gonoduct ; g.p, genital pore ; i, intestine ; m, Malpighian body 

 ■ni.d, Miillerian duct ; mn, niesonephros ; m-n}, vestigial mesonephros ; m)i^, ex 



cretory portion of the mesonephros (" metanephros ' 



, genital portion of meso- 



nephros ; mn.d, mesonephric duct; mtn.d, metanephric duct; n., nephrostome 

 ov, ovary ; p.a, abdominal pore ; p.^', peritoneal funnel ; pn, pronephros ; 

 vestigial pronephros ; s.g, shell gland ; s.s, sperm sac ; t, testis ; ug.s, u.s, urino 

 genital sinus ; v. ef, vasa eff'erentia ; v.s, vesicula seminalis. 



