Fie. 83. Obelia sp. A, portion of a colony with certain parts shown in longitudinal section; 

 B, medusa ; C, the same with reversed umbrella ; D, the same, oral aspect : Ed. 1, 2, buds ; 

 bis. blastostyle ; cce. crenosarc ; ect. ectoderm ; end. endoderm ; ent. enteric cavity ; g.th. 

 gonotheca; h.th. hydrotheca ; I, lithocyst ; m.bd. medusa-bud; mnb, manubrium ; rnsgl 

 mesogloea ; ruth, mouth ; p. perisarc ; P. 1, 2, 3, polypes ; rod. c. radial canal ; t. tentacle ,. 

 vl. velum. 



