Ser. MelanospermEjE. Earn. Chordariece. 



Plate CCCXXIII. 



ELACHISTEA SCUTULATA, Buby. 



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 

 near the bases of the filaments, concealed in the tubercle, and fre- 

 quently accompanied by paranemata. Elachistea [Fries), — from 

 c\ax«TTa, the least ; from the small size of these plants. 



Elachistea scutulata ; filaments short, rising from an oblong, convex, 

 shield-like tubercle, composed of densely packed, branching fibres ; 

 articulations twice or thrice as long as broad ; spores oblong. 



Elachistea scutulata, Buby, Bot. Gall. vol. ii. p. 972. Harv. Man. ed. 2. 

 p. 50. Kiitz. Syst. Alg. p. 540. J. Ag. Sp. Alg. p. 11. 



CoNFERVA*scutulata, Eng. Bot. t. 2311. Harv. in Hook. Br. Fl. vol. ii. 

 p. 355. Harv. in Mack. Fl. Hib. part 3. p. 227. Harv. Man. ed. 1. p. 132. 

 ed. 2. p. 50. Wyatt, Alg. Danm. no. 223. 



Hab. Parasitical on the thongs of Himanthalia lorea. Annual. Summer 

 and autumn. Very common. 



Geogr. Distr. Shores of Europe. 



Descr. Tubercles forming oblong swellings on the thongs of Himanthalia, from 

 half an inch to one, two, or more inches in length, and from a quarter to 

 nearly half an inch in thickness ; sometimes extending along the edges of 

 the thong, sometimes occupying its surface, or wholly clasping it round. 

 The tubercle is of a very solid, cartilaginous consistence, composed of 

 extremely closely packed, dichotomous, hyaline filaments, whose cells are 

 somewhat pyriform : it continues to grow in thickness as the plant ad- 

 vances to maturity. The apices of these branching filaments, at the outer 

 edge of the tubercle, bear closely-packed paranemata, and long, free, peni- 

 cillate filaments ; with spores concealed among the paranemata. Penicil- 

 late-filaments cylindrical, their cells nearly empty below, toward the apex 

 filled with an olive-coloured granular fluid. Articulations about thrice as 

 long as broad. Spores oblong, very obtuse at both ends, borne on long 

 pedicels. Substance cartilaginous, with a slimy surface. In drying the 

 plant shrinks considerably, and under pressure adheres to paper. 



This curious parasite, quite an interesting object under the 

 microscope, is found wherever Himanthalia lorea {Sca-t 'hongs) 

 abounds. It frequently completely covers the long, strap-shaped 



