ALCYONELLA EUNGOSA. 87 



it recedes from this point. The presence of the longitudinal furrow constitutes an important 

 specific character, and its value is enhanced by its being of easy application ; it occurs in two 

 out of the three species of Alcijonella. 



Another very valuable cliaracter is obtained from the shape of the statoblasts. The 

 ordinary or free statoblasts, both in Alcyonella and Plumatella, present two different shapes ; 

 in some species they are broadly elliptical, the diameters of the ellipse being to one another 

 pretty nearly in the ratio of 2 : 3 ; in others again they are narrow, the diameters bemg 

 nearly as 1 : 2. The terms broad and elongated therefore, as applied to the ova in the 

 following diagnosis, are to be understood as expressing this difference of shape. 



Generic character. — Coenoecium composed of membrano-corneous branched tubes, which 

 adhere to one another by their sides ; orifices terminal. Statoblasts elliptical, with an aunulus 

 but without marginal spines. 



Number of known species three. 



1. Alcyonella fungosa, Pallas. PI. III. 



Specific character. — Coenoecium fungoid, formed of numerous branched vertical tubes 

 destitute of a furrow. Statoblasts broad. 



Synonyms. — 1768. Tuhularia fuiKjosa. Pallas, Dcscript. Tub. Fung. Nov. Comment. Acad. Sci. 



Imp. Petropol. torn, xii, p. 5Go, tab. 14. (Original figures.) 

 1782. Sponffia lacustris. Scbmiedel, Icones Plantarum et Anal. Partium. 

 1786. Leucophra heteroclita. Miiller, Animal. Infusor. p. 158, tab. 22, fig. 27-31. 



(Locomotive embryo, original figures.) 

 1789. Alcyonium fuviatile. Bruguiere, Encyc. Metb. 1789, p. 24, pi. 472, fig. 3. 



(Original figure, bad.) 

 1802. Alcyonium fliwiatile, Bosc. Vers. vol. iii, p. 132. 

 1816. Alcyonium fluviatile. Lamouroux, Pol. flex. p. 354. 

 1816. Alcyonella stagnorum. Lamarck, An. sans Vert. 1st edit. vol. ii, p. 102. 



1820. Alcyonella stagnorum. Scliweigger, Handbuch der Naturg. p. 423. 



1821. Alcyonella stagnorum. Lamouroux, Exposit. Metb. p. 71, tab. 76, fig. 5-8. 



(Figures copied from Bruguiere.) 

 1824. Alcyonella stagnorum. Lamouroux, Enc. ]SIetb. 1824, Zoopb. p. 38. 

 1828. Alcyonella fluviatilis vel A. uttimus evolutionis gradus. Raspail, Hist. Nat. 



de 1' Alcyonella fluv., Mem. de la Soc. d'Hist. Nat. de Paris, torn, iv, 



p. 130, pi. 12-16. (Original figures.) 

 1828. Alcyonella stagnorum. Meyen, Isis, torn, sxi, p. 1225, pi. 14. (Original 



figures.) 

 1831. Alcyonella stagnorum. Ehrenberg, Symbolae Physicse Evert. Dec. 1, Pol. 



fol. a. 

 1834. Alcyonella stagnorum. Blainville, Man. d'Actiu. p. 491, pi. 85, fig. 8. 



(Figure copied from Raspail.) 



