PHYLUM MOLLUSCA 



801 



the ej-es ; and still nearer the vegetal pole a series of paired 

 ele\'ations, the rudiments of the arms. 



cir.i 



Fig. 701. — Two later stages in the development of lioligo. A, from the funnel side. B,''obliqueIy 

 from above. Letters as in x:)reccding figures ; /le. cm-t. nuchal cai'tllage. (After Korschelt and 

 Heider.) 



B 



—<^J'^ 



mant 



P^^^iTf 



Fifi. 702.— Two stages in the development of IiOligo, later than those represented in Fig. 701. 

 From the anal or funnel side. Letters as in preceding figure ; iu addition, jin, fins. (After 

 Korsehelt and Ileider.) 



After the complete enclosure of the yolk by the blastoderm, the 

 mouth (jfto.) is developed as an oval depression between the rudi- 



