Ser. Chlorosperme^e. Fam. Siphonacea. 



Plate LV. 



CODIUM SPONGIOSUM, Ban. 



Gen. Char. Frond sponge-like, composed of a plexus of unicellular 

 branching filaments, filled with green, semifluid endochrome. Fructi- 

 fication : lateral sporangia, borne on the peripheric ramuli, and con- 

 taining innumerable zoospores. — Codium (Stackh.), from kcoSiov, the 

 skin of an animal. 



Fro?ts spongiomorplia, e plexu filorum unicellulorum ramosorum conflata ; endo- 

 chromate latlvirente grmnoso. Fruct., sporangia propria, lateralia, ex 

 ramulls periphericis enata, zoosporas indejinitas foventia. 



Codium spongiosum ; frond sessile, soft, polymorphous, variously lobed, 

 sponge-like ; interior filaments laxly set in slimy matter ; peripheric 

 cylindrical or pyriform, obtuse; sporangia fusiform, acute at both 

 extremities. 



C. spongiosum; fronde sessill molli polymorpha varie lobata et spongioidea ; 

 fills iuterloribus laxiusculis in gelatlna immersis, periphericis cyllndracels v. 

 pgrlformlbus obtusis ; spermatlls fusiformibus utrlnque acutls. 



Codium spongiosum, Harv. in Trans. R. I. Acad. v. 22. p. 565; Alg. Austr. 

 Exslc. n. 577. 



Hab. On rocks and shells, etc., near low-water mark. King George's 

 Sound, very common; also at Rottnest, W. Austr., W.H.H. 



Geogr. Distr. West and south coasts of Australia. 



Descr. Frond 2-4 or more inches in breadth, very irregular in form, adhering 

 by the whole of its lower surface to the object on which it grows, and 

 spreading unequally, like a sponge, variously lobed, or tuberous ; laxly 

 filled with threads lying in a gelatinous slime, or at length hollow within. 

 The surface is velvety, the pile formed of the tips of the vertically placed, 

 peripheric ramuli of the component filaments. These ramuli vary much in 

 shape ; they are sometimes of nearly equal diameter throughout, and some- 

 times much attenuated at the base, and swollen at the extremity ; at first 

 they are filled with bright-green endochrome, but after the formation of 

 the sporangia are empty and colourless. The sporangia occur on the sides 

 of the peripheric ramuli ; they are spindle-shaped, and filled with dark- 

 green endochrome, which at length is transformed into zoospores. In 

 substance, the frond is extremely soft and tender, soon decomposing in the 

 air, or in fresh-water. It scarcely admits of being preserved by drying. 



This plant, in summer-time, is profusely cast ashore at Prin- 



