Ser. MELANOSPERME.E. ( 133 ) Fam. CHORDARIE^. 



ELACHISTA PULVINATA.— Z-^^s. 



Gen. Chak. — Fronds consisting of a more or less evident tubercular base, composed of 

 ovate cells, arranged in the form of mostly dichotomous filaments, densely packed, 

 terminating in free, simple filaments, forming a brush-like tuft. Fructification : 

 obovate spores, produced at the base of the simple filaments, and often accom- 

 panied by tufts of short, clavate " paranemata." Name from eKax^aTa, "the 

 least," in allusion to the small size of the species. 



Elachista pulvinata. — " Tufts very minute, globose, filaments fusi- 

 form, much attenuated at both ends, the basal joints three to four 

 times, the middle once and a half, the apical about as long as broad ; 

 spores linear-obovate, subsessile at the base of the filaments." 



Elachista pulvinata. — Kiltz. in Bot. Zeit. (1847) p. 144; Harv. Man. p. 50; 

 Sarv. Syn. p. 46 ; Atlas, plate 16, fig. 66. 



Elachista attenuata. — Harv. P. B. plate 28 a; /. Q. Agardh, Sp, Gen. Alg. 

 vol. i. p. 9. 



Hab. — Parasitical on Cystoseira ericoicles. — Annual. Summer and autumn. South 

 of England and west of Ireland. Perhaps not uncommon. 



Geogr. Dist. — South of England and west of Ireland ; Mediterranean Sea. 



Description. — Fronds minute, the tubercle deeply immersed in the 

 structure of the plant on which it grows, very compact, the filaments 

 nearly simple, formed of oval joints ; the filaments few, spindle-shaped, 

 slender at the base, and somewhat acute at the apex, the middle joints 

 about as long as broad, contracted at the dissepiments. Lower articu- 

 lations subcylindrical, three to four times as long as broad, those at the 

 apex monihform. Spores obovato-oblong, sun-ounded by a wide pellucid 

 limbus. Substance subcartilaginous, soft and lubricous on the surface. 



We are only acqviainted with this species in the diy state, not having 

 been fortunate enough to see it in its native haunts, although it is said 

 not to be unfrequent in the south and south-west of England and 

 Ireland, wherever the Cystoseira erkoides abounds; forming minute 

 globose tufts, scattered over the plant. The fusifoiTO filaments readily 

 distinguish it from any of the other British species. 



