32 



filaments grow fumciently entangled to retain air bubbles, and are thereby- 

 floated on the furface of the water, were confounded together, and conftitute 

 the prefent fuppofed fpecies. 



7. C. canaliculars feems to me certainly nothing more than one of the nu- 

 merous varieties of C. amphibia, which grows about mills and other falls of 

 water, exactly as Dillenius has defcribed it. This opinion is confirmed by 

 Mr. Turner's Obf rvatins on the Dillenian Herbariutn, publiflied in the Tian- 



faclions of the Linnaan Society. 



8. C. amphibia. T. 41. 



9. C. rigida. My own obfervations at Oxford confirm Mr. Turner's 

 opinion, that this is nothing but C. glomerata encrufted with fome extraneous 

 matter. 



10. C.faniculacea. This is a Fucus, as appears both by the Dillenian Her- 

 barium, and by a fpecimen which Mr. Davies received from Hudfon. By 

 calling it a Fucus I do not mean to exprefs any opinion upon its fructification, 

 which is at prefent unknown, but merely to fay that it is quite deflitute of joints- 



11. C. Uttoralis. T. 31. 



12. C. tomentofa. T. 32. 



13. C. albida. This plant, which has long been wholly unknown to Bota- 

 nilts, appears from a very careful examination of the Dillenian fpecimen, by 

 Mr. Hooker, Mr. Turner, and myfelf, under the microfcope, to be really a 

 diftm£t fpecies, and is fo defcribed in my fynopfis, and figured in the fupple- 

 mentary plate E. Mr. H. Davies has obligingly favored me with a plant which 

 had been fo named by Hudfon, and which is the C. Hookeri of this work. 



14. C. aruginoja is defcribed in my fynopfis from the Dillenian fpecimen, of 

 which a fragment is alfo reprefented in the fupplementary plate E. 



15. C. nigra. Authentic fpecimens in the Herbaria of Sir Thomas Frank- 

 land, and the Rev. H. Davies, prove that my C. atrs-rttbefcens is this fpecies. 



16. C.fcoparia. T. 52. 



17. C. canccllata is Serin/aria fpinofa. 



