CRYPTOGAMIA ALG^E. 223 



Hob. On rocks near high-water mark, common. Spring. 7/ 



The air-bladders, when dried, become as black as ebony, and 

 are sometimes polished and strung into necklaces. " Boys 

 amuse themselves with the air-bladders, by cutting the 

 larger ones transversely, near the ends, and making whistles 

 of them." The air in the bladders is common atmospheric 

 air. F. nodoms just enters the river, where, however, it 

 grows luxuriantly. 



4. F. canallculatusj frond narrow, dichotomous, channelled, en- 

 tire, without vesicles; receptacles terminal, oblong, simple or 

 bifid. LIGHT F. Scot. 917. WITH. iv. 108. HOOK. Scot. ii. 96. 

 GREV. Alg. Brit. 18. 



Hab. On rocks near high-water, plentiful, in tufts 3 or 4 

 inches high. Summer If 



5. F. siliquosus, frond narrow, compressed ; branches distichous, 

 alternate, the branchlets plane, linear, entire ; vesicles stalked, 

 oblong, nodose ; receptacles stalked, podlike, lanceolate, terminal. 

 1 to 2 feet long, olive, spreading LIGHTF. Scot. 921. WITH. 

 iv. 95. HOOK. Scot. ii. 94. Cystoseira siliquosa, GREV. Fl. Edin. 

 9S3. Halidrys siliquosa, GREV. Alg. Brit. 9. 



Hab. In pools among the rocks between low and high wa- 

 ter marks, common. If. 



125. DESMARESTIA. 



1. D. aculeata, frond cartilaginous, compressed, very narrow 

 and linear, much branched ; branches scattered, alternate, elon- 

 gate, acute, the extreme ones set with erect subulate spines. 

 Olive green, 1 or 2 feet long GREV. Alg. Brit. 38. Fucus acu- 

 leatus, LIGHTF. Scot. 924. WITH. iv. 120. Sporochnus aculeatus, 

 HOOK. Scot. 96. GREV. Fl. Edin. 287. 



Hab. Frequent on the coast in deep water. If 



126. FURCELLARIA. 



1. F. lumbricalis, olive-brown or reddish, a span high ; stalk as 

 thick as a crow-quill, thickening upwards, and at the height of 3 

 or 4 inches dividing into a level-topped bundle of acutely-forked 

 branches HOOK. Scot. 97. F. fastigiata, GREV. Alg. Brit. 67. 



