200 CLADOPHORA. 



Thompson. Root a mass of fibres. Filaments 4 6 inches high, setaceous, 

 extremely rigid, tough and wiry, tufted or subsolitary, rising with an undi- 

 vided stem for half an inch to an inch, then forked or trifurcate, and after- 

 wards repeatedly branched in a di-trichotomous or somewhat umbellate 

 manner, the uppermost branches more or less furnished with di-trichoto- 

 mous or tufted ramuli. Joints of the stem and branches very long, the dis- 

 sepiments rarely occurring except at the divisions of the branches ; in the 

 ramuli short, 3 or 4 times longer than broad. Colour a fine, glossy, trans- 

 parent green, fading much in drying. It scarcely adheres to paper. 



4. C. rectangular is, Griff. ; filaments setaceous, rigid, ir- 

 regularly branched ; branches distant, patent, set with short, 

 opposite, horizontal ramuli ; articulations twice or thrice as 

 long as broad. Harv. in Hook. Br. Fl. ii. Addenda, p. 10; 

 Wyatt, Alg. Damn. No. 145 ; Harv. Phyc. Brit. t. xii. 



In the sea, thrown up ; very rare. Summer. Torquay, Mr. Borrer and 

 Mrs. Griffiths. Roundstone, Mr. M'Calla. Arran, Galway, Mr. Andrews. 

 Filaments as thick as horse-hair, 8 12 inches long, divided in an irregu- 

 lar manner into a few principal branches ; branches patent, more or less 

 furnished with subdistant, horizontal, opposite ramuli, from a line to 

 an inch in length, and either simple or bearing a second series ; very 

 rarely, by abortion, they are alternate. Colour a full green, fading in the 

 herbarium. Substance rigid, very imperfectly adhering to paper. Joints 

 uniform throughout the plant, generally 2 or 3 times longer than broad. 

 One of the most beautiful and distinct, as it is the rarest, of the genus. 



5. C. Macallana, Harv. ; filaments setaceous, rigid, full 

 green, very flexuous, loosely bundled together, excessively 

 branched ; branches alternate, or rarely opposite, zigzag, 

 very patent; ramuli short, recurved, simple or pectinated, 

 obtuse; articulations twice or thrice as long as broad; en- 

 dochrome rather dense. Harv. Phyc. Brit. t. Ixxxiv. 



On the sandy bottom of the sea, in 4 10 fathom water. Annual. 

 Summer. Dredged in Roundstone Bay, abundantly, Mr. Wm.M'Calla. 

 Filaments forming crisped, sub-cylindrical, loose bundles 6 20 inches 

 long, bristling when removed from the water, of a rich grass-green, much 

 branched and inextricably entangled, rigid. Branches very flexuous, irre- 

 gular in length and insertion, more or less clothed with very patent ramuli. 

 This has much of the outer habit of C. rectangularis, mixed with which it 

 often occurs at Eoundstone, but may at once be known by the secund or 

 alternate ramuli. It is named in honour of its discoverer, the late Mr. 

 Wm. M'Calla, a most successful and acute explorer of Roundstone and 

 the neighbouring bays who added many new species to the Fauna and 

 Flora of Ireland, and whose early death is much to be regretted. Mr. 

 M'Calla fell a victim to the cholera in the spring of the present year, 

 (May, 1849). 



6. C. Hutchinsite. Dillw. ; filaments setaceous, cartilagi- 

 nous, rigid, glaucous green, flexuous, tufted, bristly ; ramuli 

 curved, simple or furnished on the interior face with processes 



