Prof. Allman on the Hydroid Zoophytes. 171 



coryne. In order, then, to convert this zooid into a mednsoid, 

 little more is necessary than to suppose the number of the. ten- 

 tacles increased to four by the symmetrical development of two 

 others, their extremities connected by a circular canal, and their 

 sides by a continuous muscular membrane (umbrella). 



Besides medusoids and the body now described, the only 

 other form of locomotive zooid with which T am acquainted 

 among the Phytoidal Hydrozoa is one recently described by the 

 Rev. T. Hincks (Ann. Nat. Hist. Feb. 1861, p. 74) as being produced 

 by Clavatella, a Tubularidan zoophyte discovered by him on the 

 south coast of England. Mr. Hincks has made Clavatella and 

 its zooid the subject of a beautiful memoir, and has shown that 

 the zooid is identical with the Eleutheria of De Quatrefages. 



It will at once be seen that the sexual and locomotive zooid 

 of Dicoryne is very different from that of Clavatella ; for while 

 the latter in its development and structure, as shown by Mr. 

 Hincks, is closely related to a digestive polype, the zooid of 

 Dicoryne has manifestly a nearer relation to a medusoid. 



2. Corymbogonium capillare, Alder. 



Mr. Alder, in his Catalogue, describes and figures a new 

 zoophyte under the name of Eudendrium capillare. The descrip- 

 tion and figure there given are amply sufficient for all purposes of 

 identification ; but as the specimen from which the characters 

 were drawn was preserved in spirit, it was impossible to render 

 them as complete as if the author had been in possession of the 

 living animal. 



An opportunity has recently been afforded me of examining 

 the zoophyte in a living state, having obtained it in small quan- 

 tities in May last, while dredging in the Firth of Forth ; and I 

 have thus been enabled to supply some deficiencies which must 

 necessarily exist in descriptions drawn up from spirit-specimens 

 alone. 



I have further been compelled to separate this zoophyte from 

 the genus Eudendrium, in which it had been placed by Mr. 

 Alder, and to construct for it a new one, for which I would 

 propose the name of Corymbogonium, and which may be defined 

 as follows : — 



Corymbogonium, mihi. 



Polypes with a single verticil of filiform tentacula. Gono- 

 phores (male)* in umbelliform clusters on the extremities of 

 separate non-polypiferous branches ; bilocular. Polypary invest- 

 ing the whole of the stems and branches of the ccenosarc. 



Name. — From Kopvfxfios, a cluster of berries; 701/09, offspring. 



* I have seen no female specimens; and Mr. Alder makes no mention of 

 the sex of the specimen described by him. 



