rzS Mr. Turner's Defcnpt'iom of 



which they effentlally difFer, I fhould ftill have felt very unwilling 

 to defcribe them as fpecifically diftindl, were it not for the curious 

 lines of concatenated veins which I find both peculiar to this 

 fpecies, and conftant in all the fpecimens that have fallen under my 

 obfervation. In a frefh ftate thefe veins are fo eafily vifible, as to give 

 the plant a ftriated appearance i but when dried, efpecially if faft- 

 ened upon paper, a good glafs and ftrong light are neceffary to dif- 

 cover them. I have never been able to form a fatisfaftory opinion 

 upon the office which they are intended to perform in the internal 

 organization of the fpecies; nor indeed is this a fubjeil upon which, 

 in our prefent knowledge of the marine algae, it would be right to 

 hazard a conjedlure. I fhall therefore content myfelf with obferving, 

 that they run from the midrib to the fides of the leaf generally in pa- 

 rellel lines, but fometimes branching and anaftomofing; that they arc 

 quite pellucid; and that they are interfcfted at regular diftances with 

 joints, like the filaments of Conferva:. The colour of Fucus rufcl- 

 falius is always much darker than that of Fucut Hypogloffum', the 

 leaves of a different form, and, particularly when young, very 

 blunt; the texture of the membrane, under a powerful microfcope, 

 diffimilar; the ftem far ftronger; and the midrib more prominent 

 as well as more vifible: to which is to be added, that the months of 

 January and February are thofe in which this plant bears its fruit, 

 and in which it is mofl: frequently feen upon the Yarmouth beach; 

 wliereas Fucus Hypogloffum fruftifies only in the fummer, and 

 never appears at any other part of the year. Hence I conclude, that 

 the one is annual, the other perennial. I have a fpecimen oi Fucus 

 rufcfdius with the root completely fibrous; no tendency to which 

 I ever faw in Fucus Flypoglojfum; but, this not appearing to be al- 

 ways the cafe, Ihave not confidered afingle inftan.ce fufficiently im- 

 portant to ground any part of the fpecific diftinclion upon it. In 

 the mode of fructifying, the two plants completely agree; and, a.s 

 S xnuch 



