64 BRITISH SEA-WEEDS. 



one-third of au inch wide, of exceedingly thin texture and 

 pale olive-brown colour, growing in dense tufts round the 

 leaves of Zostera marina, etc. No fructification has been 

 hitherto observed. 



Genus XXIV. ASPEKOCOCCOUS. 



Boot sh'eld-shaped. Prond a membranous tuTDular sac, 

 sometimes compressed, but always consisting of two separ- 

 able membranes. Fructification in minute clusters of spores 

 scattered over the frond. — Aspeeococctjs, from the Latin 

 nsper, rough, and the Greek eoccos, a seed. 



Various species of this genus occur on the Atlantic 

 coasts of EuropCj Africa, and America, and in the Medi- 

 terranean. Three are indigenous to the British Isles. 



Asperococcus compressus. The compressed 

 Asperococcus. 



Frond flat, from four to eighteen inches long, and from a 

 quarter of an inch to an inch and a half broad, linear- 

 lance-shaped, with an obtuse apex and short stem. Spore- 

 clusters oblong, thickly scattered over the frond. 



This plant is the connecting link between the genera 

 Punctaria and Asperococcus ; but while possessing some 

 of the characters of the former, its tubular, although 

 much compressed fronds connect it more closely with 

 the latter. 



Asperococcus Tumeri. Turner's Asperococcus. 



Fronds growing in tufts, from a few inches to two or 

 three feet long, and from half an inch to four inches in 

 diameter, tubular, inflated, obtuse at the points, contracted 

 into short stems at the base, of thin substance, and very 

 variable shape. Spore-clusters minute, roundish, thickly 

 scattered over the frond. 



