129 



Fam. Eudendridae. Hydrocaulus developed, invested with 

 a perisarc. Hydranths with the hypostonie abruptly differentiated 

 from the body and with a single set of verticillate filiform tentacles. 

 Gonophores fixed sporosacs. 



Eudendrium Ehbrg. (p. p.) Hydrophytoii consistiiig of a bran- 

 ching hydrocauhis rooted by a creeping filiform hydrorhiza. Hy- 

 dranths flask-shaped or oval with the hypostome expanded at ita 

 distal extremity so as to be more or less trumpet-shaped; tentacles 

 forming a verticil just below the hypostome. Sporosacs developed 

 from the body of the hydranth at the proximal side of the tentacles 

 or from the hydrocaulus. Male sporosacs polythalamic, female spo- 

 rosacs monothalamic. 



E. ramosum L., E. rameum Fall., E. capillare Alder, E. ar- 

 buscula Wrght., E. insigne Hincks (= E. humile AUm.), E. dispar 

 Ag., E. annulatum Norm., E. vaginatum Allm., E. tenue A. Ag., 

 E. racemosum Cav. Unbestimmbar: E. cingulatum Stimps. 



Fam. Hydractinidae- Hydrophyten forming a continuous 

 adherent expansiou, its deeper part oonsisting of freely intercom- 

 municatiug tubes of coeuosarc, each invested by a chitiuous peri- 

 sarc and all adnate to one another by their sides, its free surface 

 overspread by a layer of naked coenosarc. Hydranths with filiform 

 verticillate tentacles, Gonophores in form of fixed sporosacs. 



Hydractiuia van Bened. (= Syuhydra Quatref., Dysmorphosa 

 Phil.?) Hydranths claviform, developed at intervals from the free 

 nacked surface of the hydrophyton; tentacles filiform, forming a 

 Single circlet round the base of a conical hypostome. Sporosacs 

 ßupported by blastostyles, which arise like the hydranths from the 

 free naked surface of the hydrophyton, each carrying round its 

 distal extremity globular Clusters of thread-cells, which take the 

 place of tentacles in the hydranth. 



H. echinata Flem. (= H. lactea und H. rosea van Bened.), H. 

 polyclina Ag. 



Fam. Podocorynidae. Hydrophyton a continuous adherent 

 expansion formed by adnate and inosculating canals; the deeper 

 part with its component canals invested by a chitinous perisarc 

 while a layer of naked coenosarc spreads over the free surface. Hy- 

 dranths with verticillate filiform tentacles. Gonophores phanerocodonic. 



Podocoryne Sars (p. p.). Hydranths claviform, with a single 

 circlet of filiform tentacles surrounding the base of a conical hypo- 

 stome. Gonophores phanerocodonic, borne on the body of the hy- 

 dranth at the proximal side of the tentacles. Planoblasts with a deep 

 bell-shaped umbrella, a small four-lipped manubrium, four radiating 

 canals and four or eight marginal tentacles with bulbous bases which 

 are destitute of ocells. 



9 



