82 



COMPARATIVE ANATOMY 



CHAP. 



FIG. 78. Pallial complex and siphon of Nautilus pompilius 9 (after Bourne and Lankester). 

 r, Valve of the siphon ; /", ri^ht genital aperture ; m, the mantle fold, with the nidaraental gland, 

 full U'<1 back ; <///, anus ; cp, left ai>erture of the secondary coelom ; Ihn, left upper nephridial aper- 

 ture ; lo, aperture of the left rudimentary oviduct; Ivn, left lower nephridial aperture. The four 

 ctenidia are not lettered. 



FIG. 79. Pallial complex of Nautilus pompilius (after Bourne and Lankester). pe, Penis ; 

 a, muscle band of the siphon ; Isp, aperture of the left rudimentary seminal duct ; nepha, nephp, 

 lower and upper nephridial aperture of the left side ; olf, left osphradium ; viscper, left aperture of 

 the secondary coelom ; an, anus ; x, supra-anal papilla of unknown significance ; c, mantle cut off. 



