64 One Thousand Objects 



branchlets. The entire plant is about four or five inches 

 in length, sometimes more. (PI. VI., fig. 47.) 



462. BRISTLY SEA WEED (Ceramium riliatuni). Several 

 closely allied species are found on our coasts, the bristly 

 filaments of which form beautiful microscopic objects. 

 The present species is found attached to stones in tide- 

 pools, and the filaments are about the thickness of a hair. 

 (PI. VI., fig. 48.) 



463. CAPSULE OF SEA WEED (Polysiphonia fibrillosd). 

 This is a common species of sea-weed on our coasts, 

 and will afford good examples of capsules, as well as 

 tetraspores. The capsules are ovate, and closely seated 

 upon the smaller branches. Any species of Polysiphonia 

 will afford capsules. (PI. VI., fig. 49.) 



The following are chiefly confined to fresh water : 



464. THE PHYLLACTIDIUM (Phyllactidium pulchellum), 

 This is by no means a common species. It is found 

 adhering to the sides of aquaria, like little green discs, 

 visible to the naked eye. The structure, as seen under a 

 low power, is given in the figure. (PL VI., fig. 17.) 



465. BEADED WATER-WEED (Batrachospermum monili- 

 Jorme. Met with in standing pools or running streams. 



Stems one inch or more long, branched, covered with 

 whorls of beaded threads, which are themselves branched, 

 and bear amongst them the granular fruit. 



466. SLENDER DRAPERNALDIA (Drapernaldia tenuis). 

 Filaments convervoid and free, but gelatinous, slender, 

 and branched ; four inches long ; cells two or three times 

 as long as broad, sometimes less. In sluggish streams. 



467. BEAUTIFUL TRENTEPOHLiA(7>^/^Ma/;//<r//(?//). 

 Found growing on stones in streams, in blue-green or 

 rosy tufts, a quarter of an inch in length. Filaments 

 branched several times in a forked manner 



468. COMMON NOSTOC (Nostoe commune). Like lumps 

 of dark green jelly on gravel walks, &c., after rain. It 

 consists of a mass of beaded threads, with here and there 

 an enlarged cell, involved in gelatine. Common in 

 autumn and winter. (PI. VI.., fig. 18.) 



