IV. LAMINARIACE^.— Nereoctstis. 85 



Hab. Shores of Califoi'nia, Beechey, Coulter, Wilkes, ^'c. Unalaschka and Sitclia, 

 Postels and Bujyrecht. (v. v. ad C. B. S.) 



Boot much branched. Stems from five feet to several hundred feet long, filiform 

 or flattish, eventually subdichotomously branched. Leaves lateral, secund along 

 the branches, lanceolate, varying much in length and breadth, membranaceous or 

 coriaceous, smooth or wrinkled, bordered with slender cilia or subulate teeth ; each 

 leaf rising from an air-vessel. Air-vessels as variable in form and size as the leaves, 

 globose, ellipsoidal, pear-shaped or fusiform, or long and narrow-club-shaped. 



I fully concur with my friend Dr. Hooker in the view of this species Avhich we 

 have jointly taken in another place. {Fl. Ant. vol. 2, p. 461.) We have together 

 carefully examined specimens representing most of the forms distinguished as species 

 by authors, and still retained by Prof. J. Agardh ; and each of us, — Dr. Hooker 

 very extensively, — has had an opportunity of verifying opinions arrived at in the 

 study by observations made fi'om the living plants on the sea-shore ; and we have 

 both, independently, arrived at the conclusion that all the forms separated by 

 authors are referable to a single, and not very variable species. ]\Iany of these 

 reputed species may indeed be found growing together on different parts of the same 

 stem ; the diflferences observed being either the result of age, or of a different degree 

 of submersion, or other modifying cause. 



n. NEREOCYSTIS, Post, and Rupr. 



Stem filiform, simple, terminating in a club shaped air-vessel, from which springs 

 a tuft of dichotomously divided leaves, formed by the continual splitting, from the 

 base upwards, of an original, simple, terminal leaf. Boot branching. Fructification 

 unknown. 



Nereocystis LiitJceana, Post, and Bupr. Illustr. p. 9. t. 8. 9- Endl. Gen. PI. 3rd 

 Suppl.p). 27. J. Ag. Sp. Alg., vol. 1, p. 148. Kiitz. Sp. Alg. p. 584. Fucus Liit- 

 keanus, H. Mert. in Linn. 1829- />. 48. Hook. Bot. Misc. vol. 3, p. 3. 



Hab. North West Coast, at Norfolk Sound, Dr. Henry Mertens. (v. s. in Herb. 

 T. C. D.) 



I copy the following account of this remarkable plant from the paper of Dr. Henry 

 Mertens, its discoverer : — 



" A root, ramified in the manner of the Laminarias produces a stipes like pack- 

 thread, and everywhere of uniform thickness, about two or three feet long, and 

 suddenly swelling at the end into a perfectly round, large, bladder-nut. The upper 

 portion of this hemispherical body bears a tuft of geminate leaves, mostly rising on 



