SYNCORYNE PULCHELLA. 279 



Agassiz, however, is not only convinced of this identity, but lie maintains that the two 

 hydroids described by Loven imdcr the names of Syncoryne ramosu and ^yncoryne Sarvii, the 

 one with fixed and the other with free phanerocodonic gonophores, arc on]y different states of a 

 single species,' a view which, in my opinion, is quite untenable. 



Indeed, I am well inclined to keep all the forms with coryne-likc trophosome and fixed 

 phanerocodonic gonophores in a distinct group, generically separated from the true Syncorynes.' 

 Tlie chief argument against thus treating them is derived from the observations of Agassiz and 

 Clark as to the production of fixed and free medusae by the Syncoryne mirabilis. These observa- 

 tions, if verified, would be fatal to the proposed separation, but, as already said, I am by no 

 means convinced of their being free from error. 



The free medusa of Syncoryne mirabilis possesses at the time of its liberation a manubrium, 

 which is but little extensile, and scarcely exceeds in length half the vertical diameter of the 

 umbrella. Agassiz and Clark, however, believe that they have traced this medusa in the open 

 sea through every stage of growth up to the condition of a true Sarsia, with its elongated and 

 amazingly extensile manubrium loaded with generative elements, the very species which Agassiz 

 had already described and figured under the name of Sarsia mirahUis? 



There can be no doul)t that the changes which a phanerocodonic gonophore may undergo 

 in the period between its detachment from the trophosome and its acquisition of a sexually 

 mature state are frequently very great, and there is no reason why the medusa of Syncoryne 

 should be exempt from them. The evidence, however, adduced by the American zoologists as to 

 the ultimate form of this medusa cannot be regarded as conclusive. There is necessarily a want 

 of direct and continuous observation, and the forms figured by Agassiz as progressive stages of 

 development do not, in my mind, tend to remove the doubt. The proof has certainly not been 

 yet given that the Sarsia form is that which the free medusa of Syncoryne must ultimately attain. 



5. SrNCOErNE ptjlchella, Alhnan. 



PI. YI, figs. 1—3. 



Syncoryne pulciiella, — Allman, in Ann. Nat. Hist, for Juue, 1865. 



TROPHOSOME. — Htdrocaulus consisting of sim])le stems rising at sliort intervals 

 from a creeping reticulated stolon, and attaining a height of ahout half an inch ; 

 PEUiSARC thin, and destitt^te of annulation, but showing some indistinct transverse 

 rugEe. Htdeanths with from fifteen to twenty tentacles. 



' Agassiz, ' Contr. Nat. Hist. U.S.,' vol. iv, p. 190, note. 



" To the genus thus constituted the name of Statocodium (crraToe, k(ocwv) might be couTcnieutly 

 given. 



■' Agassi?;, " Coutributions to the Natural History of the Accaleplue of North America," ' ^lem. 

 Amer. Acad. Nat. Sc.,' 1850, y. 22J, pis. iv, v. 



