330 EUDENDRIDtE. 



bending down tlic body until the mouth is brought close to the surface on which the zoophyte 

 grows." It was found on a pecten shell dredged in the Firth of Forth. 



The other form, " AtradijUs quadritenfaculafa,'" is described as having its hydranths sessile, 

 columnar, short, provided with four alternate tentacles, two of which are long and depressed, two 

 short and nearly at right angles to the body of the hydranth. It " was found creeping along the 

 the side of a large vessel containing shells and zoophytes dredged from the Firth of Forth." 



EUDENDRID^. 



TROPHOSOME. — IItdrocaulus developed, invested with a peeisaec. Hydranths 

 with the hypostome abruptly differentiated from the body, and with a single set of 

 verticillate fiUform tentacles. 



GONOSOME. — GONOPHORES fixed SPOEOSACS. 



The hypostome, of all the species included in the family of the Eudendrida, is rendered very 

 remarkable by being abruptly differentiated from the body of the hydranth instead of passing 

 continuously into it as in other gymnoblastic hydroids. In tliis respect it resembles the hypo- 

 stome of the CampannhmdcE among the Calyptohlastea. 



ETJDENDRIUM, Ehrenherg (in part). 



Name. — From ju, Avell (beautiful) and Uv^pov, a tree, so named from the tree-like form of the 

 trophosome. 



TuBULARiA, — Linnaus. 

 Sertularia, — Cavolini. 



TROPHOSOME. — HTDEOPnYTON consisting of a branching iitdeocattlus rooted 

 by a creeping filiform HYDEOEnizA. Htdeanths flask-shaped, or oval, with the 

 hypostome expanded at its distal extremity so as to be more or less trumpet-shaped ; 

 tentacles forming a verticil just below the hypostome. 



