CCELENTERATA. 



ORDER III. SERTULARIDA. Sertularia (Sea - fir), Diphasia 

 (fig. 11), Plumularia, Antennularia. 



ORDER IV. CAMPANULARIDA. Campanularia, Obelia, Clytia, 

 Lafoea, Thaumantias, 



Fig. 11. Sertularida. A, Portion of the colony of Diphasia tamarisca, of the natural 

 size, showing hydrothecse and female ovarian capsules (gonangia). B and c, Portions of 

 different branches of the same, enlarged : A, Hydrothecse ; a, Male gonangium ; g, Female 

 gonangium. (After Hineks.) 



ORDER Y. THECOMEDUS.E. Stephanoscyphus. 



ORDER VI. HYDROMEDUSID.E (Medusidse). - 

 (fig. 12), 



Trachynema, 



(Haeckel, Das System der Medusen, Jena, 1879). 



(Huxley, Monograph of the Oceanic Hydrozoa, Ray Society, 1859 ; Kolli- 

 ker, Die Siphonophoren oder Schwimm-polypen von Messina, 1853 ; Gegen- 

 baur, Beobachtungen iiber Schwimm-polypen, Zeitschr. fiir Wiss. Zool., 1854.) 



B 



