42 ASPEROCOCCUS. 



Between tide-marks, attached to rocks, stones, corallines, or some of the 

 larger Alga. Annual. Summer. Various places on the coasts of Eng- 

 land, Ireland and Scotland. Fronds 412 inches long, $ an inch to ] 

 inch wide, obtuse, generally much tapered at the base, of a thickish mem- 

 branous, tough, subopaque substance and full brown colour. Dots of 

 fructification oblong, larger than in the preceding species, from which this 

 character, with the thicker substance and darker colour, serve to distin- 

 guish it. This has very much the outline and general appearance of 

 Laminaria fascia, with which it has sometimes been confounded. 



3. P. tenuissima, Grev. ; frond sub-linear, very thin, trans- 

 parent. Grev. Alg. Brit. p. 54 ; Hook. Br. Fl. ii. p. 279 ; 

 Harv. Phyc. Brit. t. ccxlviii. 



Parasitic on Zostera marina, &c. Annual. Summer. Fronds 2 8 

 inches long, 13 lines wide, fringing the plant on which they grow, al- 

 ways tapering at base, and often also at the apex, of an exceedingly deli- 

 cate, transparent substance, closely adhering to paper ; the margin more 

 or less toothed. Fruit unknown. According to Mrs. Griffiths this is the 

 young of P. latifolia. 



XI. ASPEROCOCCUS. Lamour. [Plate 8, C.] 



Frond unbranched, tubular, cylindrical or (rarely) com- 

 pressed, continuous, membranaceous. Root minutely scu- 

 tate, naked. Fructification scattered over the whole frond, 

 in minute, distinct dots (sort), composed of roundish, promi- 

 nent spores, mixed with club-shaped filaments. Name, 

 asper, rough, and xouxo;, a seed. 



1. A. compressus, Griff. ; frond compressed, flat, linear, 

 obtuse, tapering at base into a short stem ; dots of fructifica- 

 tion oblong. Hook. Br. FL ii. p. 278 ; Wyatt, Alg. Danm. 

 No. 8 ; Harv. Phyc. Brit. t. Ixxii. 



Cast up from deep water; rare. Annual. Summer. South coast of 

 England. Fronds 6 18 inches long, from a quarter to nearly an inch 

 wide, tapering from within an inch of the base into a minute, setaceous 

 stem ; thence upwards nearly of equal breadth, obtuse, formed of two 

 membranes closely appressed and cohering together. Colour a yellowish 

 or olivaceous green. Substance tender and adhering to paper. Dots of 

 fructification large, oblong, irregular, densely scattered over both surfaces. 

 The frond is sometimes constricted at intervals. I have gathered at the 

 Cape of Good Hope specimens exactly agreeing with those from Devon- 

 shire, except in being of larger size. 



2. A. Turner!-, Dillw. ; frond inflated, cylindrical, obtuse, 

 oblong or club-shaped, suddenly contracted at base into a 

 short stem, thin and membranaceous ; dots of fructification 

 minute, roundish. Grev. Alg. Brit. p. 51 ; Hook^ Br. Fl. ii. 

 p. 277; E. Bot. t. 2570; Wyatt, Alg. Danm. No. 59; Harv. 

 Phyc. Brit. t. xi. 



