3 66 



TYPES OF LARWE. 



Of the larval forms included in the above list a certain 



en 



FlG. 215. TWO FREE STAGES IM THE DEVELOPMENT OF SYCANDRA RAPHANUS. 



(After Schultze. ) 



A. Amphiblastula stage. 



B. Stage after the ciliated cells have commenced to be invaginated. 



f.s. segmentation cavity; er. granular epihlast cells; en. ciliated hypoblast cells. 



number are probably without affinities outside the group to 

 which they belong. This is the case with the larvae of the 



C 



13 



FIG. 216. THREE LARVAL STAGES OF EUCOPE POLYSTVLA. (After Kowalevsky.) 



A. Blastosphere stage with hypoblast spheres becoming budded into the central 

 cavity. 



B. Planula stage with solid hypoblast. 



C. Planula stage with a gastric cavity. 



(/. epiblast ; hy. hypoblast ; al. gastric cavity. 



