Illmtratiom of British Zoology. 



163 



Art. X. Illustrations in British Zoology. By George John- 

 ston, M.D. Fellow of the Royal College of Surgeons of Edia^ 

 burgh. •' 



2. Acti'nia Tue'di^e. (Jig.58.) 

 CI. Radiata, Ord. Echinoderraata, Fam. Fistulides, Gen. Actinia. ' 



A. — Corpore crasso, cylindraceo, laevi aut rugis sponte circinato ; tenta- 

 culis crassis, numerosis, conicis, striatis, castaneis, corpore brevioribus. 



A. — Body thick, somewhat cylindrical, smooth or wrinkled, with circular 

 folds J tentacula thick, numerous, conical, longitudinally striate, chest- 

 nut-coloured, shorter than the body. 



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c-Sl^tfa 



v^'i ^^ma 



The only British species of this genus to which the one 

 before us has any relation is the Actinia sulcata, described 

 and figured by Dr. Gaertner in the 52d volume of the Philo- 

 sophical Transactions^ p. 78. 1. 1. fig. 1. Both species corre- 

 spond, or at least do not differ materially, in colour and size ; 

 and they are both equally incapable of retracting and conceal- 

 ing their tentacula within the oral aperture ; but they differ 

 in the relative proportions between these organs and the body, 

 and in the sculpture of the latter, which in A. sulcata is grooved 

 in a longitudinal direction ; and this character forms so pro- 

 minent a part both in the figure and description of Gaertner, 

 that an animal destitute of any such markings, as ours is, 

 seems entitled to the rank of a distinct species ; the more par- 

 ticularly, as neither Dr. Gaertner nor myself have drawn up 

 our descriptions from one, but from the examination of seve- 

 ral individuals. : * 



M 2 



