FLORIDE^E. 



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FLORIDE.E. 



through the frond, but always grouped in 

 definite masses, generally enclosed in a spe- 

 cial capsule or conceptacle (which by the 

 naked eye may readily be mistaken for a sti- 

 chidium or tetraspore-case). The simplest 

 form of the spore-fruit consists of spherical 

 masses of spores attached to the wall of the 

 frond or imbedded in its substance, without 

 a proper conceptacle, in which latter case 

 the cells surrounding the mass of spores are 

 devoid of colouring matter ; such a fruit is 

 called afavellidium, and occurs in Halymenia, 

 and the same name is ordinarily applied to 

 fruits of similar structure not perfectly im- 

 mersed, such as those of Gigartina, Gelidium, 

 &c., where they form tubercular swellings 

 on the lobes. In some cases the tubercles 

 present a pore at the summit, when mature, 

 through which the spores find exit. When 

 such a fruit is wholly external, as in Cera- 

 mium and Callithamnion, it is called afavella. 

 The coccidium, characteristic of Delesseria, 

 Nitophyllum, &c., which is nearly related to 

 this, either occurs on lateral branches, or is 

 sessile on the face of the frond, and consists 

 of a hollow case with thick cellular walls, 

 containing a dense tuft of angular spores 

 attached to a central column. It is generally 

 imperforate, but occasionally exhibits a pore 

 through which the spores escape. The cera- 

 midium is the most complete form of the 

 conceptacular fruit, and is an ovate or urn- 

 shaped case, furnished with an apical pore, 

 and containing a tuft of pear-shaped spores 

 arising from the base of the cavity. The 

 walls are usually thin and membranous, and 

 the hollow space considerable, as in Poly- 

 siphonia, Laurencia, Dasya, &c. 



Peculiar bodies, forming external warts, 

 and composed entirely of vertical fibres, but 

 without spores, called nemathecia, are some- 

 times confounded with the conceptacular 

 fruit, and are probably immature forms of it. 



3. The spermatozoids are found in peculiar 

 structures, to which the name of antheridia 

 has been applied, from the supposed analogy 

 to the organs so called in the other Crypto- 

 gamous plants. The antheridia are produced 

 pretty much in the same situations as the 

 other organs of fructification, and are always 

 developed on different individuals. They are 

 collections of very small colourless cells, 

 sometimes collected into a bunch, as in 

 Griffithsia, sometimes enclosed in a transpa- 

 rent tube, as in Potysiphonia, or clothing a 

 kind of irregularly-shaped flat plate, as in 

 Laurencia, &c. Each of the minute cells is 

 said by Nageli and Derbes to contain a sper- 



matozoid; according to the former, a spiral 

 filament, which he did not see move ; ac- 

 cording to the latter, a transparent globule, 

 with a tail-like appendage moving actively 

 for a few moments. Thuret could not see 

 either the spiral filament or the whip- or tail- 

 like appendage, but believes that the cell of 

 the antheridium contains a transparent cor- 

 puscle, spherical in Polysiphonia, more or 

 less elongated in other genera, presenting no 

 trace of a spiral thread, but with slightly 

 granular contents. These corpuscles were ex- 

 pelled from the antheridia by a slow move- 

 ment which appeared purely mechanical, and 

 when outside, they remained at perfect rest. 



Synopsis of the Families. 



1. RHODOMELACE.E. Frond cellular, 

 areolated or articulated. Ceramidia external. 

 Tetraspores in rows, immersed in ramuli, or 

 contained in proper receptacles (stichidia). 



2. LAURENCIACE.E. Frond cellular, con- 

 tinuous. Ceramidia external. Tetraspores 

 scattered, immersed in the branches and 

 ramuli. 



3. CORALLINACE.E. Frond calcareous or 

 crustaceous, rigid. Ceramidia external, con- 

 taining the tetraspores. 



4. DELESSERIACE^E. Frond cellular, 

 continuous, areolated. Coccidia external. 

 Tetraspores collected into definite clusters 

 (son). 



5. RHODYMENIACE^E. Frond cellular, 

 continuous, the superficial cells minute. 

 Coccidia external. Tetraspores scattered 

 through the frond, or forming undefined, 

 cloud-like patches. 



6. CRYPTONEMIACE.E. Frond fibroso- 

 cellular, composed of articulated fibres, con- 

 nected together by gelatine. Favellidia 

 immersed in the frond or sub-external. Te- 

 traspores immersed in the frond. 



7. CERAMIACE^E. Frond filiform, con- 

 sisting of an articulated filament, simple, or 

 coated with a stratum of small cells. Fa- 

 vellee naked berry-like masses. Tetraspores 

 external, or partially immersed. 



8. PORPHYRACE^B. Frond plane and 

 exceedingly thin, or tubular and filiform, of 

 a purplish colour, with oval spores in sori, 

 and tetraspores scattered over the frond. 



(See under the heads of the Tribes for 

 further information.) 



BIBL. Harvey, Brit. Marine Algce, 2 ed. 

 1849, Phycologia Britannica ; Kiitzing, 

 Phycologia generalis. See also under the 

 families. 



