54 RHODOMELACE^. v. 



Hab. California, Capt. Beechey. (v. s. frustulum in Herb. T. C. D.) 



One to two inches high, with the aspect of a CladostepJms, or perhaps more nearly 

 resembling Rhodomela larix in miniature. The ramuli, though very densely set on 

 all sides, imbricate, and crowded round the ends of the branches, are scattered, not 

 whorled. The articulations are on a close examination clearly visible in the 

 branches as well as the ramuli, but, owing to the opacity of the substance, only 

 after long steeping the dry plant. The internodes are uniformly very short, the 

 tubes broad. 



I regret that I can throw little additional light on this imperfectly known plant, 

 of which I possess merely one or two minute fragments. These are different 

 from any North American specimens I have seen, but seem nearly allied to 

 P. dktyurus. The specific name verticlUata conveys an incorrect idea. 



28. PoLTSiPHONiA fastigiata, Grev. ; tufts globular, fastigiate ; filaments rigid, 

 setaceous, of nearly equal diameter throughout, many tiines dichotomous ; axils 

 patent ; internodes shorter than their diameter, many-tubed, with a dark central 

 spot; tubes sixteen to eighteen. Ag. Sp- Alg. Vol. 2, p. 67. Kiitz. Sp. Alg.p. 

 809- Harv. Phyc. Brit. t. 299- Conferva polymorpha, Linn. Dillw. Conf. t. 44. 

 E.Bot.t. 1764. 



Hab. Parasitical on Fucus nodosus and F. vesiculosus. Common on the East 

 Coast from Halifax to New York. Golden Gate, California, Capt. Pike, (v. v.) 



Tufts globose, one or two inches in diameter, dense. Filaments rigid, dark- 

 brown, excessively branched from the base, the main branches and their primary 

 divisions dichotomous, with wide axils, the ramuli less regular in ramification, and 

 often alternately multifid. All the apices are of nearly the same length, giving 

 the tuft an appearance of having been clipped all round like a thorn bush. The 

 internodes frequently show, besides their longitudinal bands, a dark central spot, 

 which is the coloured bag of the axial cell seen through the outer walls. Concepta- 

 cles ovate, somewhat acuminate, sessile near the ends of the branches, often two or 

 more close together. 



This species, though named polymorpha by the earlier writers on Algas, is very 

 constant to its characters, and if once seen, can hardly be mistaken for any other. 

 It is very constantly found on Fucus nodosus, wherever that common littoral plant 

 grows ; and more rarely on F. vesiculosus. Capt. Pike's specimens from the Pacific 

 coast are identical with Atlantic-grown individuals. 



IX. BOSTRYCHIA, Mont. 

 Frond dull purple, filiform, branched, inarticulate (or sub-articulate with very 



