136 



COMPARATIVE ANATOMY 



CHAP. 



side, and this ganglion becomes the infraintestinal gang-lion. The 

 pleurovisceral connectives, in which these ganglia lie, now cross and 

 give rise to the condition called ehiastoneury. The visceral 



M.1I3CI 



FIGS. 113, 114, 115, IKL Diagrams to illustrate the shifting forward of the pallial complex 

 along the right side of the body and the development of ehiastoneury. p, Mouth ; u1<; ////, 

 iilp, original left cerebral-, pleura!-, and pedal-ganglion ; ulpa, iirpa, original left and original right 

 parietal ganglion ; nln, original left auricle ; uos, uros, original left and original right osphradinm ; 

 iUct, -urct, original left and original right ctenidium ; -tnli, base of the mantle ; mr, edge of the same ; 

 m, mantle cavity ; c, visceral ganglion ; ve, ventricle; n, anus. 



ganglion 



as 



in which these connectives terminate posteriorly lies 

 before under the intestine. 



It is unnecessary to show in detail how this displacement also affects 

 the heart and its auricles, the osphradia, and the nephridial apertures. 



