( 82 ) 



upwards more or less clothed with uniform short setaceous or sub- 

 clavate raniuli, of which the articulations are from one and a-half to 

 twice as long as bi'oad, those of the stem being about three times as 

 broad as long. Structure consisting of a wide tube, inteiTupted by 

 thin membranous diaphragms at the joints, which are somewhat con- 

 stricted in the ramuli, but not in the stems or branches. The tube is 

 composed of angular, coloured cells, somewhat smaller towards the 

 surface. Substance of the stem firm and cartilaginous, scarcely adhering 

 to paper ; of the ramuli soft and membranaceous, more or less adherent. 

 Colour, a diill brownish red. Favellse on rather long stalks, with three 

 to fom- short sj^ine-like involucral leaves at the apex, among which nestle 

 the favellse, which are gelatinous, roundish, bilobed or occasionally 

 trilobed almost to the base, Avith a few minute, dot-like masses of spores 

 in the middle of each. Tetraspores sessile on the ramuli, triparted, and 

 surrounded by a broad pellucid limbus. 



This species is not unfrequent on the southern shores of England, 

 extending as far north on the west coast as the Island of Anglesea, where 

 it is said to be plentiful ; but it has not yet, so far as we are aware, been 

 found either in Scotland or Ireland, although it is not unlikely that it 

 may yet be met with in the latter country. Its geographical range is 

 very extensive, reaching even to Tasmania in the Southern Ocean (Phyc. 

 Brit), and it is very abimdant in many intermediate points. 



It is not so attractive either in its form or colour as many of its 

 marine neighboixrs, and may not unfrequently be overlooked, especially 

 in j)laces where its stunted appearance shows but too plainly that it 

 has reached the utmost limit of the climate suitable for its develop- 

 ment, as with us it seldom exceeds five or six inches in height, and its 

 colour is pale and sickly, while in more southern climes it can boast of 

 richer hues, and more luxuriant vegetation. 



Its favourite habitat in our northern latitude is in warm open places 

 near low-water mark, where it can receive the full benefit of the mid-day 

 sun. In the Channel Islands it is by no means unfrequent. 



EXPLANATION OF PLATE XCVIIL 



Fig. 1. — Spyridia filamentosa, natural size. 

 2. — Branchlet with favella. 

 3. — Branchlet with tetraspores. 

 4. — Tetraspores. 

 5. — Transverse section of stem. 

 6. — Longitudinal section of stem. All magnified. 



