LICHINA | LICHINACEE 43 
Orver V. LICHINACEA. 
Thallus gelatinous when moist, crustaceous, sometimes lobed 
at the circumference, squamulose or minutely fruticose. Algal 
cells Rivularia. Apothecia immersed and partly closed or open 
and with or without a thalline margin; paraphyses simple ; asci 
8-spored ; spores colourless, globose or ellipsoid, simple or septate. 
There are only two British genera :— 
Thallus minutely shrubby, maritime..................... 21. Lichina. 
Thallus crustaceous, lobed or squamulose ............ 22. Pterygium. 
21. LICHINA Ag. Syn. Alg. p. xii. (1817) (as an alga) ; 
Mont. in Dict. Hist. Nat. vii. pp. 342 & 351 (1849). (PI. 21.) 
Thallus minutely fruticose, crowdedly branched, indistinctly 
corticated, dark-coloured. Apothecia terminal, immersed in the 
globose swollen tips, almost closed ; paraphyses slender, sparingly 
branched ; asci almost cylindrical, 8-spored ; spores colourless, 
ellipsoid, simple. Spermogones single or crowded, borne near to 
the apothecia, with slender sterigmata and minute ellipsoid 
acrogenous spermatia. 
A small maritime genus long regarded as belonging to the brown 
alge. The species grow freely over rocks washed by the tide, or by 
the spray from the sea. 
1. L. pygmea Ag. Syn. Alg. pp. xii. & 9 (1817).—Thallus 
about 3} inch in height, composed of short, crowded, flat, erect 
lobes dichotomously branched and the ultimate br anchlets 
narrower, blackish-brown. Apothecia forming a globose swelling 
at the tips of the fertile branches, slightly open or irregularly 
dehiscent ; spores ellipsoid, uniseriate in the ascus, large, 22-29 
long, 11-16 » thick.—S. F. Gray Nat. Arr. i. p. 388 ; Hook. Fl. 
Scot. ii. p. 96 & in Sm. ‘Engl. Fl. v. p. 270; Grev. Fl. Edin. 
p. 286 & Scott. Crypt. iv. t. 219; Tayl. in Mackay FI. Hib. ii. 
p. 170; Mudd Man. p. 33, t. 1, fig. 1; Leight in Ann. Mag. 
Nat. Hist. ser. 3, xvi. p. 12, t. 4, fig. 21 (1865) & Lich. FI. 
p. 13; ed. 3, p. 11; Cromb. Lich. Brit. p. 2. Fucus pygmzus 
Lightf. Fl. Scot. ii. p. 964, t. 32 (1777); With. Arr. ed. 3, iv. 
p. 100; Engl. Bot. t. 1332; Turn. oe iv. p. 16, t. 204, figs. a 
toh. F pumilus Huds. Fl. Ang]. ed. 2, p. 584 (1778). 
Exsicc. Chalm. Alg. Scot. n. “40: ; Wyatt Alg. Danm. n. 155 ; 
Leight. n. 260 ; Larbal. Lich. Cesar. n. 51 ; Cromb. n. 1 ; Johns. 
n. 42. 
Long classified as a diminutive Fucus, though Lightfoot pointed 
out its great similarly to a Lichen. 
Hab. On maritime rocks below high tide.—Disty. General and 
common on rocky coasts, not recorded from N.E. Scotland.—B. M. 
Guernsey, Alderney and Jersey; Scilly Isles; Mounts Bay and St. 
Minver, Cornwall; Torbay, Ilsham Rocks, Boveysand Bay and Big- 
