272 ACTINOGONIUM. 



The Coryne raniosa of Charaisso and Eysenhardt,' recorded by Ehrenberg," under the 

 name of Si/ncori/ne Chamissotiis, is also indeterminable from want of a detailed deseription of 

 the gonosome. It is a branching species, attaining a height of about half an inch, and having 

 its gonophores clustered on the body of the hydranth just Ijelow the tentacles ; but of the 

 nature of those gonophores we have, as may be expected, no account. It was obtained on the 

 coast of La Manche. 



Among indeterminable species must also be mentioned three which were discovered by Bosc 

 on floating fucus in the open sea, and figured and described by him under the names of Cori/ne 

 proUfica, Coryne amphora, and Coryne filif era} Of these his Coryne fdifcra is probably a Clava, 

 but so very imperfect are the figures and descriptions of these hydroids that no zoologist of the 

 present day would venture to assign to them a definite place in his system. 



ACTINOGONIUM, Alhnan. 



Name. — From a/cnc, a ray, and -ydvoc, offspring. 



Syncoryne, Van Beneden. 

 Coryne, Hincks. 



TROPHOSOME. — Htdrophyton consistiDg of a developed iixduocaulus springing 

 from a creeping filiform htdrorhiza, the whole invested by a conspicuous perisarc. 

 Htdranths claviform, with scattered capitate tentacles. 



GONOSOME. — Sporosacs developed from the body of the hydranth, and giving 

 origin to actinuljd. 



The genus Actinorjoiiiujii is founded on a hydroid, described by Van Beneden under the 

 name of Syncoryne ptmilla, i)ut which, judging from the account given by the Belgian naturalist, 

 difi"crs altogether from the genus Syncoryne by the earlier stages of its development. Its mature 

 trophosome is that of a Syncoryne or of a Coryne, but its development is from an actinula instead 

 of a planula, a character Avhich I I'cgard as of sufficient importance to entitle it to a distinct 

 generic rank. 



^ ' Nov. Act.,' \, p. 370, tab. xxiii, fig. 3 a, b. 



' ' Corallenthiere,' p. 295. 



^ Bosc, ' Hist. Nat. des Vers.,' tome ii, pp. 339-tO, pi. x.\ii, figs. C — 8. 



