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ZOOLOGY 



Clathroznon, an Australian genus, resembles it in having branched 

 and intertwined coenosarcal tubes, the perisarc of which under- 

 goes tusion ; but the complex mass thus produced, instead of 

 forming an incrustation on a shell, is a large, abundantly branched, 

 tree-like structure, resembling some of the fan-corals or Gorgonacea 

 {vide infra). Ccratella (Fig. 106) has a similar fan-coral-like 

 appearance, with a branching axis composed of numerous inter- 



FlQ. 106.— Ceratella fusca. About nat. aize. (From HickBOU, after Baldwin Spencer.) 



twining and anastomosing tubes ; but while Clathrozoon possesses 

 thecsB, in Ceratella they are absent. 



A great simplification of the colony is produced in Myriothcla 

 (Fig. 105 S), in which the short ccBnosarc bears a single large 

 terminal hydranth, and gives off numerous slender branches which 

 bear the reproductive zooids (s). Even greater simplicity is found 

 in Gorymorpha (3), in which the entire organism consists of a 

 single stalked polype, from the tentacular region of which the 

 medusae (m) arise. 



