PREVIOUS INTERPRETATIONS OF CNIDARIA 157 



into their distal part (corresponding to the anthocyathus of 

 Fungia; one could therefore speak here of a "scyphocyathus" 

 which, however, would be completely superfluous) which 

 produces the larvae (ephyrae) of Scyphomedusae by way of 

 a repeated transverse division (i.e. strobilation) . It is in these 

 ephyrae that the gonads arrive at their sexual maturity. 

 I maintain that originally individual ephyrae only wxre deve- 

 loped (the primarily monodiscal strobilation); it was only 

 later that the transverse division began to be repeated at 

 certain regular intervals. The genuine strobilation, however. 



Fig. 29. Monodisc strobilation of Cassiopea sp., with a bud, 

 (after Bigelow). 



has been developed only secondarily, i.e. when the transverse 

 division became a multiple one (the appearance of several 

 simultaneous transverse divisions, or the polydiscal strobila- 

 tion). This again has further led to a secondary single and 

 unequal transverse division (the secondary monodiscal strobi- 

 lation which is actually no longer a strobilation because 

 it does not lead to the formation of a strobila-like form 

 [Fig. 29]). This has finally led to a complete abandonment of 

 the transverse division. 



