THE ALGAE OF BERMUDA. Ill 



Gracilaria dichotomo-flabellata Crouan in Maz^ & Schramm, 

 Algues de la Guadeloupe, p. 218, without description. A disco parvo, 

 stipite brevi subtereti vel compresso, mox in frondem planam regulari- 

 ter dichotomam abeunte, segmentis linearibus 5 mm. ad 2 cm. latis, 

 apicibus obtusis vel truncatis; axillis latis, rotundatis; substantia 

 membranacea, juniore tenuiore, adultiore crassiore et firmiore; colore 

 laete- vel fusco-rubro; tetrasporangiis sparsis; cystocarpiis magnis, 

 ad superficiem utrinque sparsis. 



8. G. horizontalis sp. nov. Fronde a disco centrali irregulari 

 horizontaliter expansa, ramis quoquoversum exeuntibus, subteretis, 

 crassis, ramos ferentibus densissimos, minime attenuatos; cellulis 

 interioribus magnis, corticem versus minoribus, cortice submonostro- 

 matico, cellularum minutarum coloratarum. Fructificatione ignota. 



Frond expanding horizontally from a central irregular disk, emit- 

 ting on all sides very densely set branches, tapering very little; inte- 

 rior cells large, becoming smaller towards the submonostromatic 

 cortex, which is formed of small colored cells. Fructification unknown. 



The habit is unique in the genus; the plant seems to creep over the 

 bottom of the pool in which it grows, much in the same way as do the 

 haptera of a Laminaria; the tips of the branches, or short projec- 

 tions on the margins or lower surface, adhering to the substratum quite 

 firmly. If a young but vigorous frond of Laminaria were cut off at 

 the base of the stipe, just at the level of the upper haptera, the remain- 

 ing basal part would give a good idea of the appearance of this species. 

 Plants growing together are almost inextricably entangled, and even 

 when a plant is not in contact with others, it is difficult to detach it. 

 The substance is tough and cartilaginous, the color of the more or 

 less wrinkled surface is dull yellowish brown, but the lower part, not 

 exposed to the light, is of the clear purplish red found in other species 

 of Gracilaria. It was found in rock pools at low water mark at 

 Gravelly Bay, Aug. 27, 1913, Collins. Type in Collins herb.. No. 

 7818. Since found at the same station in Feb. and April, at Harris 

 Bay, April, Hervey. 



Hypnea Lamouroux. 



1. Branches long, virgate, often with hooked tips. 1. H. musoiformis. 



1. Branches not virgate, no hooked tips. 2. 



2. Forming a low, dense, matted expansion. 3. H. spinella. 



2. Erect fronds from a matted base, slender, with patent ramuli. 



2. H. oervicornis. 



