AND SPECIES or HTDEOIDA. 253 



fascicled, very much branched, with a subalternate disposition of 

 the branches, which ascend at a small angle from the main stem 

 and from one another ; ultimate ramuli annulated at their origin, 

 rest of the hydrocaulus smooth, except with an occasional annu- 

 lation here and there. Hydrauths with about forty tentacles. 



Gonosome. Gronophores springing from the ultimate ramuli at 

 some distance below the hydranth. 



Locality. Kattegat, collected by Mr. Oersted, Zool. Mus. Cop. 



The gonophores in the specimen were not sufficiently far ad- 

 vanced to enable their ti'ue structure to be determined ; and little 

 more than their position in the hydrosoma can be asserted of 

 them. Their appearance, however, renders it highly probable 

 that they become developed into planoblasts of the type met with 

 in the genus Perigonimus ; but in the absence of an accurate 

 knowledge of the developed gonosome, the reference of the pre- 

 sent species to that genus cannot be viewed as otherwise than 

 provisional. 



The most striking peculiarity of the species is the great number 

 of tentacles in the hydranth. 



EUDENBBIIDM. 



EUDENDRIITM. 

 EUDENDRIUM RIGIUUM. Plate IX. figs. 3, 4. 



Tropliosome. Hydrocaulus attaining a height of about one inch, 

 much and very irregularly branched, springing out of an entangled 

 mass of tortuous wiry filaments, fascicled in the main stem aud 

 principal branches ; subordinate branches not fascicled, capillary, 

 and strongly annulated throughout, the whole forming rigid tufts. 

 Hydranths with about twenty tentacles. 



Gonoso7ne not known. 



Locality. Denmark, Zool. Mus. Cop. 



There can be little doubt that the Hydroid just described is a 

 true Eudendrium ; for though no gonosome was present in the 

 specimen, the trophosome is entirely that of a Eudendrium ; 

 and, from all we know of the species of Eudendrium, the tropho- 

 some of this genus will in itself afford characters sufficient for 

 generic determination. 



The species here described bears a considerable resemblance to 

 Eudendrium capillare ; but the strongly fascicled condition of the 

 main stem aud principal branches, and the complete annulatiou 



