336 EUDENDRIUM ARBUSCULA. 



Localities. — Coast of Nortluimberland, Mr. Embletoii ; Plymouth, ilr. Alder; Toihay, 

 Devonshire, Rev. T. Hincks; Firth of Forth and Torbay, G. J. A. 



The first description of Eudendriiim capiUare is that given by Mr. Alder, who drew up its 

 characters from a specimen preserved in spirits. Some time after this I dredged the same 

 hydroid in the Firth of Forth from a depth of about five fathoms. The complete atrophy of the 

 gonophore-bearing hydranths led me to regai'd it as the representative of a new genus, which I 

 accordingly described under the name of Cori/mbot/onitan. A more thorough investigation of 

 the genus Eudendriiim, however, has since convinced me that this genus may present in the 

 hydranths which carry the gonophores, even in one and the same colony, every degree of atrophy, 

 from the fully developed hydrantli to the mere remnant of this body after mouth, hypostome, 

 and tentacles have entirely disappeared. The blastostyle-like condition of the hydranth, therefore, 

 in the genus Eudendriiim is a character of little importance, and can in no way justify a generic 

 separation. The genus Coryinboyoniuni must accordingly be absorbed into the older genus 

 Eudendriiim, in which Alder had originally placed it. 



The Eudendrium capiUare is a small but elegant hydroid. It is abundant at extreme low- 

 water spring tides in some parts of the Firth of Forth, where it may be found attached to the 

 outer coarse tunic of some of the common Ascidians. Its distribution in Britain is a wide one, 

 for it is also abundant on the Devonshire coast, where I have dredged it from a depth of about 

 four fathoms, growing on ] Ij/drall mania falcata and other common hydroids. 



4. EUDENDEITJM ARBUSCULA, Wright. 



Eudendrium arbuscula, — SlretliiU IVriyht, in Edin. New Phil. Journ. for July, 1859, pi. ix, 



figs. 5, 6. Hincks, Brit. Hydr. Zoopb., p. 84, 

 pi. xiv, fig. 1. 



TROPHOSOME. — Hydkocaulus "forming a bushy tree of adnate stems ; branches 

 ringed near their insertions." Htdkanths "white, terminal, on very slender and 

 transparent branches, and with numerous alternate tentacles ; base of body surrounded 

 by a ring of large thread-cells." 



* GONOSOME. — Male spouosacs " borne in clusters on short stems springing at 

 right angles from the branches. Summit of the double capsule with a tubercle con- 

 taining barbed thread-cells." — Strethill Wright. 



I have never met with this species. It is described by Dr. Strethill Wright from a single 

 specimen, which he states to have been about two inches in height, and to have been obtained 

 at Queen's Ferry, Firth of Forth, in the month of September. 



