Ser. Melanospermeje. Fam. Chordariea. 



Plate CCLXI. 



ELACHISTEA STELLULATA, Griff. 



Gen. Char. Frond parasitical, consisting of a dense tuft of free, simple, 

 articulated, olivaceous filaments, rising from a common tubercular 

 base, composed of vertical, branching fibres, closely combined into a 

 cartilaginous mass. Fructification, pear-shaped spores attached to the 

 bases of the filaments concealed in the tubercle, and frequently ac- 

 companied by paranemata. Elachistea [Fries), — from eXaxia-ra, 

 the least ; from the small size of these plants. 



Elachistea stellulata ; tufts very minute, stellate ; tubercle composed of 

 large cells ; filaments short, tapering to the base, linear club-shaped, 

 obtuse ; articulations about twice as long as broad, uniform ; parane- 

 mata with short articulations. 



Elachistea stellulata, Griff. MSS. Aresch. Pug. in Linn. vol. xvii. p. 261. 

 tab. 9. f. 4. Earv. Man. ed. 2. p. 51. 



Myrionema stellulatum, J. Ag. et Gen. Sp. Alg. vol. i. p. 49. 



Conferva stellulata, Harv. Man. ed. 1. p. 132. 



Hab. Parasitical on Bictyota dic/wtoma. Annual. Summer. Torquay, 



Mrs. Griffith. 

 Geogr. Distr. Not observed out of England. 



Descr. Tufts exceedingly minute, scarcely half a line in diameter, appearing 

 like dark brown specks, dotting over the surface of the Bictyota, and under 

 the microscope resembling miniature echini. Tubercle well developed, com- 

 posed of dichotomous strings of large, colourless cells. From the terminal 

 cell of each string the filaments and paranemata arise. Filaments a quarter 

 of a line in length, linear-clavate, gradually tapering from the obtuse apex 

 to the base the articulations of nearly uniform size, all being from once and 

 a half to twice as long as broad, constricted at the joints. Each articulation 

 contains a bag of rather dark coloured endochrome. Paranemata very 

 numerous, springing with the filaments, and* about one-third as long, with 

 very short articulations, club-shaped. Spores unknown to me. They are 

 figured by Dr. Areschoug as obovate-oblong. 



This minute and microscopically beautiful little plant was dis- 

 covered some years ago by Mrs. Griffiths on the old fronds of 

 Dictyota dicholoma, and first described in the first edition of the 

 Manual of British Algae. I have not seen any other specimens 

 than those originally collected by Mrs. Griffiths, who met with 

 the parasite infesting several specimens of the Dictyota ; nor am 

 1 aw arc that any other observer has noticed it in Britain, or that 



