Sek. MELANOSPERME.E. (167) Fam. ECTOCARPEiE. 



ECTOCARPUS AMPHIBIUS.— m/t'. 



Gen. Char. — "Frond capillary, jointed, olive or brown, flaccid, single-tubed. Fruit, 

 either spherical, elliptical, or lanceolate utricles (or spores), borne (externally) 

 on the ramuli, or imbedded in their substance." Name from e'lCT^s, "external," 

 and Kapxhs, "fruit." A name equally applicable to many other genera, and 

 unfortunately only to a few of the species in the present. 



EcTOCARPUS ampliibms. — Fronds tufted, very delicate, slender, and 

 flaccid, subdichotomous or alternate ; articulations two to three times 

 longer than broad ; " uti'icles (1) linear attenuate, spine-like, mostly 

 sessile, and scattered." — Phyc. Brit. 



EcTocARPUS amphibius. — Harv. P. B. plate 183; Raw. Man. p. 58 ; Harv. 

 Syn. p. 54; Atlas, plate 20, fig. 85; /. G. Agardh, Sp. Gen. Alg. 

 vol. i. p. 25. 



Hab. — In muddy ditches of brackish water, near the coast. Tide-ditches communi- 

 cating with the Avon, below Bristol {Mr. Thwaites). 



Gkogr. Dist. ? 



Description. — Filaments very slender and flaccid, one to three inches 

 long, •' growing on the mud or attached to various substances," much 

 branched in an iiTegularly dichotomous manner ; ultimate ramuli altei*- 

 nate or secund, short, subulate and acute, all suberect. Articulations 

 two to three times as long as broad in the main stems, somewhat 

 shorter upwards ; cylindrical, scarcely constricted at the dissepiments, 

 variegated (in the dried specimens at least) with patches, and inter- 

 rupted bands of condensed endochrome. Fructification : " the ramuli 

 are frequently changed into exceedingly long, sessile, opaque, sporaceous 

 bodies, evidently analogous to the utricle of Ectocarpus siliculosm, and 

 of a character intermediate between these and the immersed fructifica- 

 tion of E. littoralis.'' — Fhi/c. Brit. Substance veiy flaccid, and adhering 

 to paper. Colour, a pale yellowish olive. 



This species we have only seen in the dry state ; it is said to grow in 

 ditches of brackish water, and in such places may be not unfrequeut, or 

 it is quite possible, as remarked in Phyc. Brit, that it may be merely 

 *' a variety of E. silicidosus, altered by its growing in water containing a 

 very small quantity of salt." Even in this view it is interesting, and 

 its history deserves investigation, with a view to ascertain the effect 

 which such an influence would have upon the development of the species. 



