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PALUDICELLIDtE. 

 Genus VIII. Paludicella, Geroais, 1836. 



Name. — A diminutive noun, formed from pahcs, standing water. 



In tlie number of the ' Symbolse Physicse,' published in 1831, Elirenberg described under 

 the name of Alcyonella articulala, a fresh-water Pol3rzoon which he discovered in the neigh- 

 bourhood of Berhn. M. Gervais shortly afterwards, having discovered near Paris an animal 

 which agreed with Eiirenberg's description, saw the necessity of separating it from Alci/onella 

 and placing it in a distinct genus, which he named Paludicella. About the same time 

 Ehrenberg's animal was detected in the neighbourhood of Louvain by M. Van Beneden, and 

 in Lough Erne, in Ireland, by Mr. William Thomjjson, of Belfast, who was thus the first to 

 add this interesting Polyzoon to the Fauna of the British Isles. 



Paludicella is one of the best marked of all the genera of fresh-water Polyzoa ; its 

 perfectly orbicular lophophore, with tlie absence of epistome and calyx, and its strikingly 

 articulated coencecium, formed of regular claviform cells, all separated from one another 

 by complete septa, together with several peculiarities in its internal structure already 

 described, remove it by a well-marked interval from the other genera of the present mono- 

 graph, and approximate it to certain marine representations of tlie class. The genus consists 

 as yet of but a' single species. 



Generic character. — Coencecium membrano-corneous, branched ; branches composed of a 

 series of claviform cells placed end to end and separated from one another by complete septa ; 

 orifices tubular, lateral, placed near the wide extremity of each cell. Lophophore orbicular, no 

 epistome or calyx. Statoblasts not observed. 



Species unica. Paludicella Ehrenbergi, Van Beneden. PI. X. 

 Specific character. — The same as those of the genus. 



Synonyms. — 1831. Alcyonella articulala. Ehrenberg, Symb. Phys. Evert., Dec. 1, Pol., fol. a. 

 1832. AlcyoneUa diuphana. Nordmann, Mikrograph. Beitriige, vol. ii., p. 75. 



1836. Paludicella articuluta. Gervais, Comptes Reud. 



1837. Paludicella. Gervais, Ann. Sc. Nat., 2d series, torn, vii, p. 80. 



1839. Paludicella articulala. Gervais, Ann. Fraug. et Etrang. d'Anat., torn, iii, p. 75. 



1839. Paludicella. Van Beneden, Bull. Ac. Brux., torn, vi, 2d part, p. 278, fig. 1. 



(Original figure.) 



1840. Paludicella articulee. Gervais, Diet. Sc. Nat., Suppl., vol. i, pi. 1, Pol. Fluv., 



fig. 6. (Original figure.) 

 1842. Paludicella articulala. Allman, On the Muscular Syst. of Palud., &c., Roy. 

 Irish Acad., No. 38, witlt a plate. (Original figure.) 



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