LOW-WATER MARX. 79 



verse section, we find six siphons. The fruit is broad 

 oval capsules and small tetraspores imbedded obscurely 

 in slightly swollen ramiui, more or less dark pnrple. 



This is very local, abundant near Plymouth, and is 

 one of the proofs why a seaweed collector should by 

 no means despise mud-banks, for here also will be 

 the finest CallitJiamnions, such as Callithamnion Bor- 

 reri and Blumula. 



Poltsipho^ia Parasitica. — This is so different 

 from the others, that it must be obtained if possible. 

 Look for it on the Ilelolesia at low tide. It has 

 fronds more like a tiny fern, when spread out fan- 

 like on the paper. Colour, a fine clear red. To find 

 this pretty specimen, go to the extremest edge of the 

 water, and on the sides of the rock, on clumps of 

 the coralline called Melobesia, we find small tufts of 

 one or two inches high, well worth bringing home. 

 The stem is like Polysiplionia Elongella, marked by 

 hexagonal cells concealing eight siphons. This plant 

 in structure closely resembles another, Bytiplilosa Com- 

 -planata, and may be compared with it. (See " Mid- 

 tide Pools.") 



Poltsiphoxia Atro-Eubescens. — This grows in 

 dense tufts of brown-red in lowest- tide pools. Though-; 

 from its somewhat straggling and black appearance, 

 we might not value it much, yet the structure is sur- 

 prisingly beautiful under the microscope ; the twelve 

 siphons being twisted spirally up the joints, and under 

 water it is of a delicate crimson lake colour. The fruit 

 is abundant, and the plant common on our coasts. 



