IV 



PHYLUM CCELENTERATA 

 ORDER 2. CORONATA, 



177 



This group includes a number of rare and beautiful Medusae of curiously 

 complex structure, of which Pericolpa may be taken as an example. The 

 umbrella (Fig. 133) is usually conical, and is divided by a horizontal furrow 



9-f- 



i.r. 



frr.t 



FIQ. 131. Tessera princeps.**^, external view ; S, vertical section, ^./..jgastricifilament ; 

 gon. gonad ; i.r. t. inter-radial tentacle ; mnb. manubrium ; lmth.[mouth ; p.r. t. per-radial 

 tentacle ; st. stomach ; tn. tteniole. (After Haeckel.) 



Fia. 132. Lucernaria. A, oral aspect ; B, from the side. g. foot-gland ; g.f. gastric 

 filaments ; gon. gonad ; mth. mouth ; t. tentacles ; In. taenioles. (After Claus.) 



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