32 ANTHOZOA IIYDROIDA. 



same genus by Mliller, who, at a subsequent period, figured and de- 

 scribed it witb an elegance aud accuracy whicli almost defies compe- 

 tition. It seems to have been a favourite with him : " Animalium, 

 qua3 Zoophyta dicuntur, nullum elegant ius, observatorique magis 

 gratum esse potest." There can be no doubt, however, that the 

 opinion of Pallas, in regard of its affinities, is more correct than that 

 of Forskal and Miiller ; and had the present fashion of subdividing 

 natural families into genera on characters of secondary value been 

 then in vogue, undoubtedly the easy task of distinguishing, by a 

 name, this naked zoophyte from the sheathed Tubularia would not 

 have been left to any of his successors. 



2. Hydkactinia,'" Van Beneden. 



Character. — Polypes naked, gregarious^ united on a common 

 crustaceous hase ; tentacula in one suhalternating circle ; eggs 

 or hulbules sessile, clustered, on untentaculated individuals. 



According to Van Beneden, this genus is synonymous with 

 the Bysmorpliosa of Philippi, the SynJiydra of Quatrefages, 

 the Cordylopliora of Allman, and the Echinochorlum of 

 Hassall. (Ann. Nat. Hist. xv. p. 248 ; Bull, de TAcad. Roy. 

 de Brux. xii. No. 2.) In referring Cordylophora to it, Van 

 Beneden is obviously wrong, as he himself seems latterly to 

 have suspected. (Bull. sup. cit. p. 14.) Of the sameness of 

 Synhydra with Echinochorium there can be no doubt ; but 

 Mons. de Quatrefages maintains that the genus Synhydra is 

 not only different from Hydractinia, but from all the genera 

 with which Van Beneden has associated it. After an atten- 

 tive perusal of the friendly discussion which has passed be- 

 tween these naturalists, the correctness of Van Beneden's 

 conclusions appears to me to have been proved. Whether the 

 name Hydractinia or Echinochorium has the prior claim for 

 adoption I cannot ascertain positively. Both were publislied 

 in 1841. I have preferred the nomenclature of Van Beneden, 



* A compound of Hydra and Actinia. The character given to the genus by Van 

 Beneden is : " Polypes nus ; les tentacules fonnant un seul verticille ; les oeufs 

 sessUes en grappe, situes a la hauteur des tentacules. Tous les individus voisins 

 sont unis entre eux et ferment une couche. Point de polypier." — Rech. sur TEm- 

 bryog. des Tubulaires, p. G2. 



