282 ALGtE INARTICULATiE. [Haliseris. 



Marine rocks at Appin, Argyleshire, Capt. Carm'whael. Miltown 

 Malbay, Ireland, Mr. Harvey. Slaty and sandstone rocks near high-water 

 mark in Berwick Bay, Dr. Johnston. — An inch to an inch and a half broad, 

 the specimens often imbricated, deep rich brown, opaque. This has, at 

 the first appearance, a close affinity with P. (Zonaria, Ag.) squamaria from 

 the Mediterranean, where the fronds are often equally orbicular, but 

 they are woolly beneath, the substance is thinner, less opaque, and the 

 concentric lines are very evident. P. deusta had hitherto been considered 

 a native only of the extreme northern regions. " Fronds gregarious, coria- 

 ceous, opaque, of a brownish purple colour, and marked with concentric 

 strise or zones, about an inch in diameter, suborbicular, flat, and adher- 

 ing firmly throughout the whole lower surface, but separating without 

 much difficulty. Fructification unknown." Carm. " Thin slices," 

 Mr. Harvey observes, of this plant, "placed under a high power of the 

 microscope, appear closely cellular, with irregular polygonal meshes or 

 cellules, for there is no regular reticulation, like that of others of the 

 Genus. This species is often papillose, and much resembles a Thele- 

 phora. I believe it belongs to a distinct genus, of which I doubt not 

 there are many species often overlooked as crustaceous zoophytes." 



3. P.pdrvula, Grev. (small Padina) ; frond resupinate sub- 

 orbicular membranaceous deeply lobed, lobes orbicular some- 

 what imbricated, scarcely at all marked with concentric lines. 

 Grev. Crypt Fl. t. 360, Alg. Brit.p. 63. 



Rocks in the sea, near Sidmouth, Dr. GrevUle. Rocks near low- 

 water mark, Miltown Malbay, Ireland, rare, Mr. Harvey. . March.— 

 I have not seen English specimens of this plant. Mr. Harvey, who 

 communicated his Irish specimens to me, observes in a letter, " Since I 

 have become possessed of the Cryptogamic Flora, I find by Dr. Gre- 

 ville's figures, that the reticulation on our plant is different ; yet they 

 quite accord in habit, resembling a Marchantia, creeping by its white 

 radicular fibres over a space of a foot or more in extent ; sometimes 

 very closely attached to the rock, at others comparatively loose. In 

 structure, both plants are true Dictyotece. The reticulation in my plant 

 is less regular than in Dr. Greville's, and the meshes are shorter than 

 they are broad. If distinct, I propose to call mine P. decumbent." 



21. Hali'seris. Tozzetti. Haliseris. 



Frond flat, linear, membranaceous, witb a midrib. Root a 

 mass of woolly filaments. Fructification; ovate seeds, forming 

 distinct sori or groupes (mostly arranged in longitudinal lines). 

 Grev. Alg. Brit. p. 63. t. 8.— Name, aM, *M, the sea, and <rgg/;, 

 endive; signifying sea-endive. 



l.H.polypodioides, Ag. (Polypodium-like Haliseris); frond 

 dichotomous obtuse entire at the margin, seeds solitary and 

 scattered over the frond or arranged in oblong clusters parallel 

 to and near the midrib. Ag. Sp. Alg. v.}. p. 142.— Fucus 

 poh/podioid., Lamour. — F. membranaceus, Stackh. Ner. Brit. t. 6. 

 Turn. Syn. Five. p. 141, Hist. Fuc. t. 87. E. Bot. t. 1758. 



Rocks in the sea, Torbay and Sidmouth, Mrs. Griffiths. Cornwall, 

 Mr. Rashleigh. Shields beach, Mr. Winch. Opposite Quilty Strand, 

 at extreme low-water mark, Miltown Malbay, Ireland, rare, Mr. Harvey. 



