66 ALQM. 



very similar to those existing in the antheridia of the 

 mosses ; these, escaping through the pore of the con- 

 ceptacle, fertilize the spores. 



The figure (20) in the plate was drawn from a con- 

 ceptacle of Fucus serrdtus, another common species, 

 differing from F. vesiculosus in having the margins of 

 the frond serrate ; the antheridia of the two species 

 do not, however, differ in any important respect. 

 To examine the conceptacles of Fucus and their con- 

 tents, the receptacles should be soaked in water, if 

 not fresh, and thin sections made with a sharp knife. 

 They form very beautiful objects, and may be pre- 

 served in chloride of calcium or glycerine. 



FLORID'E^E, or Rhodosper'mese (poSov, rose, crTrep- 

 fj,a, seed). The second Order of Algse, forming the 

 Floridese (flos, a flower), comprises the red sea-weeds; 

 a few of them are purple, or greenish-red ; so that by 

 the colour alone they may be readily distinguished 

 from the Fucoids, and from nearly all those of the 

 next Order, the Confer' voids. A few of them are leaf- 

 like, or possess flat fronds ; but most of them consist 

 of finely divided or feathery fronds. They are often 

 found upon the sea-shore of a dirty white colour, the 

 colouring matter having been decomposed or washed 

 out by rain. 



We shall consider a few of the genera and species 

 under the heads of the families to which they belong. 



CORALLINA'CE^E, the Corallines, or calcareous Algae. 

 In this family we have the beautiful Corallina offi- 

 cindlis (PI. IV. fig. 28), the common Coralline, which 

 is very abundant on the sea-shore, attached to larger 

 sea- weeds, shells, and rocks. It is hard and chalky, 

 from the presence of a large proportion of carbonate 

 of lime in its minute cells. The fronds are composed 

 of jointed and branched filaments. The fructification 

 (figs. 29 and 30) consists of ovate cellular capsules, or 

 ceramid'ia (/eepa/uov, earthen vessel), placed mostly 

 at the ends of pinnate stalks, and containing a tuft 



