STEREONEMA. 



[ 616 ] 



STIGMA. 



Tulasne, Ann. des Sc. nat. 3 ser. xvii. p. 197; 

 Engl Bot. pi. 282. 



STEREONEMA, Kiitz.— Probably the 

 mycelium of a fungus. 



BiBL. Kiitzing, Sp. Alg. p. 160. 



STERIGMATA.— The term apphed by 

 Tulasne to the filaments forming the pedicels 

 of the spermatia in the Fungi (PI. 20. figs. 

 2,3). 



STICHIDIA. — Pod-shaped processes of 

 the fronds of Florideous Algse, containing 

 the tetraspores imbedded in them (fig. 160, 

 page 189). 



STICHOCOCC US, Nageh=PROTOCOC- 

 cus. 



STICTA, Ach. — A genus of Parmeliaceae 

 (Gymnocarpous Lichens), with a tough, foli- 

 aceous thallus, growing over rocks and 

 trunks of trees, mostly in mountainous 

 districts. S . pulmonaria forms large shaggy 

 fronds of olive-green colour when fresh, pale- 

 brown when dry, pitted and reticulated; the 

 apothecia mostly marginal, red-brown. The 

 spermogonia of this genus occur scattered 

 on the upper surface, mostly near the ends 

 of the lobes. 



BiBL. Hook. Brit. Flor. ii. pt. 1. p. 208 ; 

 Tulasne, Ann. des Sc. nat. 3 ser. xvii. p. 169. 

 pi. 1 ; Engl Bot. pi. 572. 



STICTEI3 Fries.— A group of Helvellacei 



Fig. 702. 



Fig. 704. 



Fig. 703. 



^•T*r~^ i 





Sticta versicolor. 



Fig. 702. An open disk, emerged on the surface of 

 wood, having an irregular border. 



Fig. 703. Vertical section of the same. 



Magnified 20 diameters. 



Fig. 704. Asci and paraphyses from the last. Magni- 

 fied 200 diameters. 



(Ascomycetous Fungi), containing several 

 genera of plants, growing on wood, branches 

 of trees, &c., bursting through from beneath 

 the bark when mature. S. {Cryptomyces, 



Berk. ; Propolis, Fr., S. Veg.) versicolor 

 (figs. 702-704), is common on wood; the 

 upper surface of the open fruit is white, and 

 at length mealy. 



BiBL. Berk. Brit. Flor. ii. pt. 2. p. 214, 

 Ann. Nat. Hist. vi. p. 359; Fries, Summa 

 Veg. p. 372. 



STIGEOCLONIUM, Kiitz.— A genus of 

 Chsetophoracese (Confervoid Algae), growing 

 mostly in brooks, and composed of delicate 

 branched filaments, draw n out into delicate 

 hyaline points ; attached to stones and form- 

 ing masses of a sinuous or lubricous cha- 

 racter. The jointed filaments are composed 

 of short cells, possessing bright green con- 

 tents ; the entire contents of a cell are con- 

 verted into a single zoospore (with four 

 cilia) and discharged (PI. 5. fig. 5), and the 

 cell-wall is so delicate that it generally 

 vanishes at the same time. Many species 

 are described by Kiitzing, formerly regarded 

 as members of the genus Draparnaldia, 

 which difi'ers in the number of zoospores 

 produced in each cell, and in possessing 

 large primary filaments with lateral tufts of 

 delicate ones, resembling those of Stigeo- 

 clonium (fig. 182, p. 216). We select the 

 most distinct of the British forms. 



1. S. protensum (PL 5. fig. 5). Tufts of 

 filaments 1-36 to 1-60" high, very much 

 branched and elongated ; primary filaments 

 1-1800" in diameter, joints equal or three 

 times as long {Drap. condensata, Hassall, 

 pi. 11. fig. 1). 



2. S. luhricum. Tufts about 1-36 to 

 1-72" high; primary filaments 1-2160" in 

 diameter ; torulose ; set above with nume- 

 rous tufts of abbreviated branchlets {Drap. 

 tenuis, Hass. pi. 11. fig. 2). 



3. S. elongatum. Filaments very slender; 

 primaries 1-2880" in diameter; branches 

 erecto-patent, often opposite, subramulose, 

 flagelliform; all the joints three or five times 

 as long as broad {Drap. elongata, Hass. 

 pi. 10. fig. 3). 



4. S. nanum. " Filaments highly mucous, 

 very slender, sparingly branched, branches 

 acuminate, not usually ciliated (produced 

 into a filiform end); cells rather broader 

 than long" {Drap. nana, Hass. pi. 10. fig. 4). 



BiBL. Kiitzing, Sp. Alg. p. 352, Tab. 

 Phyc. iii. pis. 1-11 ; Hassall, Brit. Fr. Alg. 

 fig. 118; Thuret, Ann. des Sc. nat. 3 ser. 

 xiv. p. 223. pi. 18. 



STIGMA.— The part of the pistil of An- 

 giospermous Flowering plants, upon which 

 the pollen rests to produce its pollen-tubes, 

 and where the orifices exist leading to the 



