ornm. 



I 



Fig. 5 Spinax niger. A., embryo no. Ill; B., embryo no. VI; C, young 

 specimen; Sm., senticetum. 



Fig. 6 Spinax niger. A transverse section through the siphon (haemalum- 

 eosin), Ep., stratified epithelium; M., muscle; m. s. c, mucus secreting cells. 



226 



