SIPHONACE.E. 31 



VII. BKYOPSIS. Lamour. 



Root fibrous. Fronds tufted, each consisting of a single, erect, branching, unicel- 

 lular, cylindrical filament ; branches and ramuli either imbricated or pinnate. Cell- 

 vmU firmly membranaceous, glistening. Endochrome granular and viscid, at length 

 converted into zoospores, which escape through apertures formed in the cell-wall. 



This genus consists of several littoral Algte of small size, but among the most ele- 

 gant of marine plants. They occur in tufts, seldom more than two to four inches in 

 height, and grow either on the rocky margins of clear tide-pools, or epiphytically on 

 other Algae. The frond is affixed to the rock by a slightly developed fibrous radicle, 

 or simply by a disc, and consists of a single cylindrical elongated branching cell, filled 

 with dense, starchy endochrome of a deep green colour, and destitute of any septum or 

 interruption of the cavity throughout the whole length of the tube. The ramification 

 is very generally on a pinnate type ; a primary undivided filament emits lateral virgate 

 branches, also quite simple, and these are generally naked in the lower half of their 

 length, and furnished with lateral, distichous or imbricated ramuli in the upper half. 

 In some species, as in B. Balbisiana, there are either no ramuli or very few ; in others, 

 as in B. myura, the ramuli are exceedingly numerous and densely set. Very many 

 species have been named and described, with more or less care, by authors ; but many 

 rest on very uncertain characters, and I fear that several must be regarded as mere 

 varieties of B. plumosa, the original and most widely dispersed species. All are 

 remarkable for a glassy lustre, when dry. They retain their colour, if carefully dried, 

 and adhere closely to paper. 



1. Bryopsis plumosa, Lamour. ; frond setaceous, decompoundly much branched ; the 

 ultimate branches filiform, virgate, naked in their lower half, and. more or less plumoso- 

 pectinate above ; ramuli simple. Ag. Sp. Alg. 1. p. 448. Harv. Fhyc. Brit. tab. 3. 

 Kiitz. Syst. Alg. p. 493. Ulva plumosa, E. Bot. t. 2375. — Var. P. densa ; branches 

 excessively crowded, the ultimate divisions pinnate near the apex, the pinnai some- 

 times secund. — Var. 7 secunda ; tufts matted ; fronds irregularly much branched ; 

 branches flexuous, many of them naked, others set in the upper half with falcato- 

 reflexed, secund (occasionally bilateral) ramuli. (Tab. XLV. A.) Var. h ; ramulosa ; 

 branches nearly naked, with a few scattered, secund ramuli. Bryopsis ramulosa. Mont. 

 Hist. Cuba, p. 16. Tab. S.Jig. 2. (Tab. XLV. A.) 



Hab. Between tide marks in rock pools. Various localities near New York, com- 

 mon. Charleston, South Carolina, and Key West. Vars. /9, 7, and B, intermixed with 

 the ordinary form at Key West and Sand Key, W.H H. (v. v.) 



Root small, scutate, accompanied by lateral, entangled fibres, and sometimes matted. 



