Van Benedcn on the yenera Ekutbcria and Synhydra. 247 



that thc! Eleutheria arc the early stage of the Synhydra or of an 

 allied genus. 



During lute years we have seen several examples of animals 

 which, after having escaped the most minute researches of natu- 

 ralists, are all at once discovered at the same time in countries 

 \cvy distant from one another. Wc have lately had a very remark- 

 able example of this kind : the Branchiostuma luhricum, the most 

 curious being ])erhaps of the whole aniuial creation, was discovered 

 by Costa in the Bay of Naples, almost at the same time as j\OI. 

 Sundewall and Loven found it in the Baltic, and Yarrell on the 

 English coast. 



We may ask if these animals make their appearance all at once 

 in different localities, as some seem to think, or whether it is the 

 state of science that leads to this result. A^ e confess we are 

 strongly disposed to believe that it is an inevitable result of the 

 j)rogress which science is constantly making. The attention of 

 naturalists is at the ])resent day concentrated on these lower ani- 

 mals which have been so long despised ; for indeed their organi- 

 zation and their develo])ment must throw an important light upon 

 the obscure functions of the higher animals. ■" 



We may point out here a further example of what we have just 

 said. In my memoir on the Tubuhirioi I established a new ge- 

 nus in that family. In the month of Januaiy 1839, I discovered 

 it after a great storm in the midst of many objects cast upon our 

 coast. In the sitting of January 6th, 1841, I mentioned it, and 

 designated it by the name of Hydractinia. 



After the publication of my notice, my friend M. Gervais re- 

 called to my recollection that we had observed during our stay at 

 Cette in 1838 a very closely allied l)ol}q3, probably of the same 

 genus, and of which he had preserved a rude sketch. He had 

 observed it whilst I was engaged in studying the embryogeny of 

 Aplysia. He has mentioned it under the article Zoophyte in the 

 'Dictionn. Pittoresque d'Histoire Naturelle.' 



In 184-2 ]M. Phili])pi published a description in Wiegmann^s 

 ' Archiv ' of a new polyp under the name of Dysmorphosa conchi- 

 cola from the Bay of Naples. It only requires to cast one's eye 

 upon the figure to see that it is the same animal which we ob- 

 served at Ostend. 



At the meeting of the British Association at Cork in 1813, 

 ]\Ir. Allman mentioned a new hydroid zoophyte which formed 

 the link between the Corynes and the Hermia. He calls it Cor- 

 dylophora"^. The few words of the author leave no doubt that it 

 is the same animal which we had figured. 



[* Ann. Nat. Hist, vol.xiii. p. 328.— Ed.] 



