SUPPLEMENT. 



No. 1. Additional Species discovered siuce the publication of the 

 First and Second Parts. 



Part I.— MELANOSPERME^. 



Part 1, p. 61, add, 



I.* TURBINARIA. Lamour. 



Root branching. Frond alternately decompound, having a distinct stem, branches, 

 vesicated leaves and receptacles. Branches filiform, simple or pinnate. Leaves spirally 

 inserted, on long petioles, peltate, becoming inflated and changed into peltate air-vessels 

 with leafy dentate margins. Becepfades cylindrical, verrucose, much branched, rising 

 from the petiole of the leaf, near its base, on the upper side ; of similar structure to 

 those of Sargassum. 



A genus consisting of two or three tropical or subtropical Algse, distinguished from 

 Sargassum by its peltate leaves, whicli are at first thin and flat, but afterwards become 

 hoUow and are changed into flat-topped, margined air vessels. 



1. TuRBiXARiA vulgaris, kg. ; frond membranaceo-coriaceous ; leaves on an inflated 

 petiole obconic or top-shaped, the margin entire or toothed, the disc naked. /. Ag. Sp. 

 Alg. 1,|5. 267. TurUnaria denudata and T. decurrens, Bory. Fucus turhinatus, 

 Turn. Hist. t. 2A,Jig. a. and h. 



Hab. At Key West, Mr. Ashmead. (v. v.) 



Boot a mass of branching fibres, as thick as sparrow's quills, loosely entangled 

 together. Fronds several from the same mat of roots, either quite simple, or dividing 

 near the base into three or four principal branches ; or piunately compound by the 

 evolution of lateral branches, erect and rigid, 6-10 inches high, cylindrical and smooth. 

 Leaves spirally inserted, spreading to all sides, patent, rigid ; petioles at first cylindrical, 



R 



