334 EUDENDRIUM RAMEUM. 



2. Ettdendbium RAMEUM, Pullas. 



TuBULARiA RAMEA, — PdUus, Eleuduis, p. 83. Ball/el/, Rare and Remarkable Animals, vol. i, 



p. 5, pis. vi, vii, viii, ix. 

 EuDENDRiu.M RAMEUM, — Johnstoti, Brit. Zooph., 1847, p. 45, pi. v, figs. 1, 2. Hincks, Brit. 



Hydr. Zoopli., p. 80, woodcut fig. 8. 



TROPHOSOME. — Htdrocaulus profusely branched, attaining a height of from 

 three to six inches, fascicled in the main stem and principal branches ; main stem 

 attaining a thickness of more than a quarter of an inch, and as well as the principal 

 branches very irregularly ramified ; branches ultimately losing their fasciculation, and 

 then consisting of single capillary tubes, wliich may continue to branch before the 

 emission of the ultimate or hydranth-bearing ramuli, which are regularly alternate in 

 their disposition ; perisarc rigid, occasionally marked with nearly obsolete annulations 

 on the smaller branches. Hydranths with about twenty tentacles, frequently 

 atrophied in the male after the production of gonophores. 



GONOSOME. — Male sporosacs two-chambered, borne upon the body of the 

 hydranth in a verticil immediately below the tentacles ; female sporosacs oval, 

 scattered on the hydrocaulus for some distance below the hydranth. 



Colour. — Hydranths rose colour, hydrocaulus reddish brown, female gonophores brownish 

 orange. 



Hahitat. — Attached to stones, old shells, &c., in the sea. 



Bed hi/metrical dislnbution . — Deep-sea zone. 



Localities. — Mediterranean, Pallas; coast of Norway, Sars; Firth of Forth, Sir J. G. 

 Dalyell and G. J. A. ; coast of Northumberland, Dr. Johnston and ]\Ir. Alder ; Shetland Islands, 

 Firth of Clyde, coasts of Lancashire and Cornwall, and east coast of Ireland, Mr. Hincks. 



EudendriiiM ramcum, with its massive trunk and boughs, sending off smaller and smaller 

 branches, until these, in the wonderful profusion of their ramification, terminate in the delicate 

 hydranth-bearing twigs, is perhaps the most tree-like of all our hydroids, and might well have 

 suggested the generic name under which it is associated with other tree-like forms of these 

 beaxitiful animals. 



It is certainly very nearly allied to the Eudendrium ramosum of Linna;us, more nearly, 

 indeed, than has been suspected by the systematic writers who have described it, and who have 

 followed Pallas in regarding its fascicled stems as affording the main grounds of distinction 

 between it and the species just named. Eudendrium ramosum, however, is also a fascicled form, 

 and the chief difference between the two species will be found in the nnich more massive stems 

 and main branches of Eudendrium. rameum, and in its more irregular ramification and rigid 



