2 26 CON KLIN. 



EXPLANATION OF PLATE IX. 



Fig. 95. Vertical longitudinal section, stage similar to Fig. 78. At the pos- 

 terior end the section cuts the intestine as a tube (cf. Figs. 76 and 81). 



Fig. 96. Coronal section of embryo of stage shown in Fig. 78, taken through 

 apical organ, cerebral ganglia, and foot. 



Fig. 97. Section from same series as preceding, two sections farther back, 

 showing cerebro-pedal connectives and otocysts. 



Fig. 98. Section similar to preceding, taken just posterior to the opening of 

 the stomodaeum into the mesenteron. 



Fig. 99. Horizontal section of embryo similar to Fig. 79, taken in the direction 

 of a line connecting the points O and V^ in that figure. 



Fig. 100. Horizontal section of embryo similar to Fig. 76, showing formation 

 of otocysts and intestine. 



Fig. ioi. Horizontal section of embryo similar to Fig. 80, taken a little above 

 reference line V of that figure. 



Fig. 102. Horizontal section of embryo similar to Fig. 80, taken near the 

 dorsal side and through the intestinal cell plate which forms the dorsal boundary 

 of the intestine at the point where it opens into the mesenteron (see Fig. 80). 



Fig. 103. Section from same series as preceding, lying a little nearer the ven- 

 tral side, and taken through the opening of the stomodaeum and of the intestine 

 into the mesenteron. 



Fig. 104. Horizontal section of an older embryo, taken nearer the ventral side 

 than the preceding, about the level of the ocelli of Fig. 82. 



Fig. 105. Section from same series as preceding, but nearer the ventral side, 

 taken at the level of the otocysts in Fig. 82. 



