782 



ZOOLOGY 



SECT. 



aperture with minutely lobed margin, situated on a slight eleva- , 

 tion, but by no means so prominent as in Sepia. On each side ; 

 are two apertures, the oral and aboral nephridial apertures (Fig. 

 680, a. 1. neph., pt. neph.), corresponding to the single pair of 

 Sepia, but not elevated on papilla?. Close to each posteriori 



r. anl.os 



den, : 



neph, 



- ctn. 



p. os 



pi. neph 

 i.visc.ap 



FIG. (580. Nautilus pompilius, interior of mantle-cavity of a male specimen with th 

 postero-ventral wall reflected, a. I. neph. oral left nephridial aperture; (//>. anus; ctcn 

 ctenidia ; ey. eye ; ./'. funnel ; I. <$ aj>. left reproductive aperture indicated by a bristle passe 

 through it ; 1. rise. ap. left viscei-o-pericardial aperture ; n. s. Needham's sac ; pen. penis 

 pt. neph. aboral left nephridial aperture ; p. os. aboral osphradia ; /. anl. os. right oral ospl 

 diuni ; v. n. visceral nerves. (After Willey.) 



nephridial aperture is an opening the wscero-pericardial (I.visc.ap. 

 r. vise, ap.) leading into the pericardial section of the coelome 

 these are not represented in Sepia. In both sexes there are t\v< 

 reproductive ducts, right and left ; but in both the right alone 

 appears to be functional, and the left is much the smaller. Th< 



