SECT. n. SPONGIOCARFE&. 237 



threads running from wall to wall. Bhabdonia (fig. 26 A) 

 belongs to this group. 



The Wrangeliacese are filiform, many species consist- 

 ing of a central thread coated more or less with smaller 

 ones, sometimes so disposed as to form a most elegant 

 lace work. Each joint of the stem, branches, and branch- 

 lets is beset with whorls of short slender forked and 

 jointed ramuli. They have clusters of spores in stalked 

 capsules. The spore threads of Wrangelia penicillata 

 (fig. 26 c) are surrounded by a whorl of ramuli composed 

 of radiating pyriform spores arising from the endochrome 

 of terminal cells. 



The Squamarise resemble lichens in spreading them- 

 selves in a red crust over stones and rocks. They have 

 roots below, and warts, on their upper surface, in which 

 there are tufts of moniliform spore-bearing threads. 

 The tetraspores of Cruoria pellita are shown in fig. 26 D; 

 its repeatedly forked filaments taper upwards, and the 

 tetraspores are formed in the swollen centre cell of the 

 filaments. The Peyssonnelia grows on shells and other 

 marine objects, and extends from the Mediterranean to 

 Ireland, and the east coast of North America. 



The Polyides rotundus (fig. 23 A), representing the 

 only genus of the Spongiocarpese, has a dark purple 

 solid gristly cylindrical stem, repeatedly and regularly 

 forked, all being of the same thickness. The tips of 

 the last forkings, which are small and equal, give the 

 top of the plant a rounded form. The microscope shows 

 that the stem and branches are composed of a central 

 column of interlaced threads and radiating cells; it 

 shows, moreover, that hyaline nuclei containing a cluster 

 of conical spores whose broad bases radiate in all di- 

 rections from a centre, as in fig. 23 a, are scattered 

 among the articulated threads of oblong irregular spongy 

 warts which clasp or embrace the stem and branches. 

 The tetraspores are buried in the ends of the last forks. 



