no 



Genus W. Fredericella, Gervais, 1838. 

 Name. — In honour of Frederick Cuvier. 



In 1774 Blumenbach gave the name of Tubidaria sultana to a little fresh-water Polyzoon 

 which he found in the neighbourhood of Gottingen, and which diifered from all the then known 

 fresh-water species in having the tentacula disposed in a circle instead of forming a crescent. 

 This circular disposition of the tentacula, which at once distinguishes Blumenbach's animal 

 from all the other fresh-water species except PalndiceUa, was properly considered by 

 M. Gervais to be of sufficient importance to cause the Tubularia sultana to take the rank 

 of a distinct genus, and he has accordingly assumed it as the type of his genus Fredericella. 



Though the tentacular crown, however, may at first appear quite similar in its form to 

 that of Paludicella, a careful examination will detect in the lophophore a deviation from the 

 orbicular condition presented by this part in the latter, and the bi-laterality of the lophophore in 

 Fredericella is still further maintained by the presence of the epistome, which is altogether 

 absent in Paludicella. The epistome and calyciform membrane are, indeed, as well developed 

 in Fredericella as in the species with crescentic lophophores, while Paludicella, the only genus 

 with a truly orbicular lophophore, is also the only one in which the epistome and membi-ane 

 are absent. The whole structure, moreover, of Fredericella is quite in accordance with that 

 of the species with crescentic lophophores, and differs in many important particulars from the 

 structure of Paludicella, so that notwithstanding the circular disposition of the tentacula 

 the true affinities of the genus are with Plumatella rather than Paludicella 



Generic character. — Coenoecium confervoid, composed of a membrano-corneous branched 

 tube, with the branches distinct from one another and terminated by the orifices. Lopho- 

 phore nearly circular; tentacular crown campanulate. Statoblasts bean-shaped, destitute 

 of annulus and spines. 



Species unica.* F. sultana, Blumenbach. PI. IX. 



Specific character. — The same as that of tlie genus. 



Synonyms. — 1777. Tubidaria sultana. Blumenbach, Handbuch der Naturgeschichte. (Original 

 figure.) 

 1789. Tubularia sultana. Gmelin, Linn. Syst. Nat., p. 3835. 



* In my Synopsis of Presli-water Zoophytes, published in the ' Annals of Natural History,' 

 1844, I have described as a distinct species, with the specific name dilatata, a Fredericella in which 

 the branches become dilated towards the extremities; subsequent investigations, however, have led me 

 to look upon the F. dilatata of that publication as a merely accidental variation of F. sultana, and the 

 species must accordingly be suppressed. 



