58 



ANTHOZOA HYDROIDA. 



8. HALECIUM, Oken."* 



CHARACTER. Polypidoms rooted, plant-like ; the stem com- 

 posed of aggregated subparallel capillary tubes ; the branches 

 alternate, spreading bifariously : cells tubular, subsessile, 

 jointed at the base, arising alternately from opposite sides 

 one under every joint of the branchlets : ovarian vesicles 

 irregularly scattered. Polypes hydraform, scarcely retractile 

 within their cells. 



Fig. 7. 



Halecium is very nearly allied 

 to Laomedea. There is, however, 

 a difference in the habit of their 

 species, and the polype- cells are 

 sessile or nearly so. These have 

 been described as formed " like 

 tubes with two joints." They 

 consist of two portions, one 

 inserted in the parietes of the 

 celliferous tube ; and from this 

 basal portion the other, which is 

 the true cell, issues, being con- 

 tracted and ringed at the root. 



aperture 



1. H. HALECINUM, vesicles oval or oblong, 

 shortly tubulous, subterminal. Jas. Newton.-}- 



PLATE VIII. 



Corallina scruposa pennata, cauliculis crassiusculis rigidis, Raii Syn. i. 36, no. 15. 

 Herring-bone Coralline, Ellis in Phil. Trans, abridg. x. 454, pi. 10, fig. E. F. G. 



* "HALECIUM Oken Lehrb. Naturg. 1815. Halec." Agissiz in Norn. Zool. Polypi, 

 p. 1 3. The genus is the same as the Thoa of Lamouroux, which, on the autho - 

 rity of Agassiz, we learn was not defined until 1816. 



j" Mr. James Newton, a good practical botanist, contemporary with Ray, to whom 

 he sent many contributions for the Synopsis Stirpium Britannicarum, and the Hist. 

 Plantarum. He died before the publication of the third edition of the Synopsis in 

 1724 ; but Dillenius acknowledges his obligations, and introduced several species into 

 our Flora, for the first time, on Newton's authority. I am not aware that any genus 

 of plants has been dedicated to his memory, an honour of which he seems not 

 unworthy. He must not be confounded with another James Newton, author of a 

 " Compleat Herbal," Lond. 1752. 



