286 



COMPARATIVE ANATOMY 



CHAP. 



Fig. 224.— Pelagotliurla natatrix (after Ludwlg), completed ; from above. I, Body ; 2, amis. 



Fig. 225.— Pelagotliurla natatrix (after Ludwlg) ; front view, i.e. from the oral pole. 1, Mouth ; 

 2, oral tentacles ; 3, disc ; 4, canals of the disc. 



