for the Microscope, 63 



coast. When in fruit, the smaller branches are swollen 

 at intervals into darker striate receptacles. 



452. GRANULOSE CONFERVA (Ectocarpus granulosns). 

 Not an uncommon marine Conferva, growing on othei 

 sea-weeds. Differing considerably in appearance from 

 the last and the mode of producing its fruit. 



453. RED DASYA (Dasya cocdnea). A section of the 

 lower portion of the stem of this sea-weed is recom- 

 mended. 



454. THREADY POLYSIPHONIA (Polysiphonia byssoides). 

 One of the handsomest of British sea-weeds, especially 

 when young, and of a beautiful pink colour, with delicate 

 slender branches. 



455. LATTICED CONFERVA ( Enteromorpha clathratd). 

 Grass-green, much branched, with latticed cells. -^Com- 

 mon in rock pools. 



456. ELONGATED POLYSIPHONIA (Polysiphoniaelongata). 

 A section of the stem of this rather common species is 

 also deserving of notice. 



457. DITCH CONFERVA (Conferva litorca). A common 

 Conferva, found in salt-water ditches, of a dull green 

 colour. Cells one and a half times as long as broad, 

 with here and there a pair of swollen cells. 



458. INVOLUCRE OF SEA WEED (Griffithsia sp.}. In 

 some species the tetraspores are attached to short branches 

 arranged in a circle, so as to form a kind of involucre. 

 (PI. VI, fig. 44.) 



459. FRUIT OF CORALLINE (Coralhna officmalis). The 

 receptacles in this common coralline contain tufts of 

 tetraspores of an elongated form, with the four spores 

 placed end to end. (PI. VI., fig. 45.) 



460. FAVELL^E (Callithamnion tetragonwri). This 

 beautiful red alga is a parasite on larger species. The 

 tetraspores are very small, but the favellas are large and 

 easily detected, seated on plumules less than half a line 

 in length. (PI. VI, fig. 46.) 



461. BINATE SPORES (Ectocarpus Mertensii). This is a 

 common species on mud-covered rocks near low- water 

 mark. The binate spores are immersed in the smaller 



