The subject of the present plate, though in some degree known 

 to Linnaeus, who confounded it with Fucus disticJius, was first 

 clearly described by Desfontaines in 1798, under the name of Fucus 

 polj/jjodioides ; and in 1801 figured by Mr. Stackhouse in the first 

 number of his " Nereis Britannica," under that of Fucus membra- 

 naceus. The former appellation, which alludes to the resemblance 

 which its fructification bears to that of a Polypodium has been 

 generally adopted. As may be seen by the number of stations on 

 record, this plant is widely distributed over the warm parts of the 

 world. In the British Islands it is decidedly rare, and chiefly found 

 on the southern and western shores. It does not appear to be found 

 in Scotland. In the south of Europe it is common, especially in 

 the Mediterranean, and has been brought from the tropics of 

 either hemisphere. I have not seen Cape specimens, but Ecklon 

 is reported to have gathered it in Algoa Bay. 



Mrs. Griffiths, who first discovered the scattered spores, finds 

 occasionally specimens in which the frond is marked, in the place 

 usually occupied by the sori, with brown, wavy, map-like lines 

 enclosing spaces which are usually more transparent than the rest 

 of the frond. They probably indicate a diseased state of the fruit- 

 producing cells. 



Several other species of Haliseris are now known, all natives 

 of warm latitudes, and all with much the same habit. Some have 

 thick, almost coriaceous fronds ; and others are much more tender 

 and delicate than the European species ; some have serrated, and 

 others crisped margins ; but the mode of branching is similar in 

 all. 



Fig. 1. Haliseris polypodioldes, with sori. 2. A segment, with scattered 

 spores : — natural size. 3. Portion of a frond with scattered spores. 4. Por- 

 tion of a frond with a sorus. 5. Spores from the sorus : — all more or less 

 highly magnified. 



