138 ECTOCARPACE^.— EcTOCAEPus. iv. 



lY. ECTOCARPUS. Lyngh. 



Frond capillary, articulated, variously much-branched, flaccid. Articulations 

 composed of a single cell, short, rarely twice or thrice as long as broad. Apices 

 attenuated. Spores spherical or ellipsoidal, scattered (rarely produced.) Propagula, 

 or pod-like bodies, oblong, conical, linear or lanceolate, transversely striate, and 

 celluloso-granulated, formed either of transformed ramuli, or of some portion of a 

 ramulus, or of portions of the main and secondary branches. 



A large genus of confervoid Algae, usually much branched, and forming fine, 

 feathery tufts of slender, soft, brownish or olive green filaments. The articulations 

 are always very short, and nearly of equal size in all parts of the plant. They are 

 iTsually filled with endochrome, which is sometimes pellucid, sometimes granulated, 

 and sometimes condensed into a dark spot in the middle of the cell. The species 

 are difficult to determine or fix limits to, owing to the uncertain nature of the 

 ramification, which it is by no means easy to characterise, and which appears to 

 vary in dififerent specimens collected together and seemingly of one species. The 

 best characters are derived from the propagula^ or " silicules," as they have been 

 called ; podlike bodies regarded as fructification. These are either formed in the 

 substance of the branches, or of the whole substance of a shortened branchlet. 

 They contain a darker endochrome than the unchanged branches, and are divided at 

 minute intervals by transverse lines. The spaces between the lines are broken up 

 into granular cells disposed in transverse bands, and supposed to be reproductive. 



The American species are not yet fully worked out, and though I have proposed 

 some new ones below, I am by no means certain that they ought all to be retained. 

 Some are but partially known, and all require a careful investigation on the sea 

 shore. Solitary specimens of these plants are by no means sufficient, and when any 

 seemingly new form is observed among them, numerous specimens ought not only 

 to be collected, but the collector should notice what other seemingly diff'erent Ecto- 

 carpus was growing with the supposed novelty ; and should carefully compare one 

 form with the other before assuming that he has a new species to describe. This 

 cannot be done at a distance, and in many cases I have had to decide fi'om very 

 insufficient materials. 



* Propagula short or elongated ^formed in some portion of the larger or lesser branches, 

 (not in the ultimate ramuli). 



1. EcTOCARPUS hrachiatus, Harv. ; finely tufted, feathery, much branched ; tlie 

 branches free, opposite or quaternate ; ramuli opposite, very patent ; pi'Ojjagula 

 forming oblong or elhptical swellings in the smaller branches, or at the point where 

 two opposite ramuli issue. Harv. Phyc, Brit. t. 4. /. Ag. Sp. Alg. l,p. 20. 



